# Electrical current drop issue...



## lil65gto (Jan 19, 2017)

So my 1st cruise of the year ended with a tow home...The Fitech unit once again failed and would not all the car to start (mostly hard to start when warmed up).
I call Fitech and they stress to check the white wire which is my switched wire that is tied in with the ignition switch. I meter this while on the phone with tech and it shows about 12v exactly when switch is turned but drops as low as 1.5v when i roll the engine over. Tech advises me that i cannot have voltage drop here and this is the source of my issues.
Battery is older but meters out at 12.4v at rest. 
The voltage regulator is new as well.

Suggestions? Bad ignition switch or voltage regulator or even battery? I'm a bit confused here...

Thanks!


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## PontiacJim (Dec 29, 2012)

Temporarily, I'd run a known 12V sourced jumper wire, something with a toggle switch (on/off) to your white wire to eliminate your switch, voltage regulator, & battery. Turn the switch "on" to provide power as you fire your car up normally. If it runs well, and you do not see any voltage drop as you did with the current wiring, then I would begin to do some tracing. But me, if it worked with an on/off toggle switch, I'd keep it that way and maybe even hide it as a means to foil any would-be thief. Just sayin' as this is the best I can come up with not using anything but the old antique carburetor thingy on my cars. :thumbsup:


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## lil65gto (Jan 19, 2017)

I did run a jumper wire from the battery to this white wire, essentially bypassing the switch. The car fired right up.
I guess my true question is: would this be a sign of a bad ignition switch? It just seems odd that the voltage drops so low when you crank the engine.


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## PontiacJim (Dec 29, 2012)

lil65gto said:


> I did run a jumper wire from the battery to this white wire, essentially bypassing the switch. The car fired right up.
> I guess my true question is: would this be a sign of a bad ignition switch? It just seems odd that the voltage drops so low when you crank the engine.




Hmmm. Tough to say. I would think that some voltage drop would occur when you normally crank your engine. An ignition switch can go bad and I have had several go out on me, but they usually get finicky in that one time they start them they don't, then repeated tries gets it to fire, etc.. This is usually the tell tale sign its going.

Now there could easily be some resistance within the system somewhere due to age/corrosion of one of the wires. I found a wiring diagram here, if this is for your car: Pontiac wiring 1957-1965


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## lil65gto (Jan 19, 2017)

Thank you...lots to look at here i guess. Easiest thing would be to just find another switched source to splice into...lol


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## Lemans guy (Oct 14, 2014)

I had a bad ignition switch do exactly that on my lemans. Changed the switch and back to normal. But I also wanted to get 12 volts to my distributor since I put in a Petronix instead of points. An easy way to do this is to take the white "ballast" run wire, and connect it to the 12 volt start wire, I spliced them with a crimp,solder,shrink butt connector.......

Then run a wire from that to the switch contact on a 12 volt relay. You then run a solid regulated 12 volt power source to the relay hot...and from the relay out to your coil.

You also add a small inline diode to the brown wire from the alternator that goes to dash battery warning light, to prevent run on.

This then works this way,...your start gives the relay switch 12, your run gives the relay 9 volts or so,...but the relay will close at about 5 volts and will stay closed with about 1.5 volts........but all the time will give full regulated power to your coil through the relay...and spark of course.

Now you have to fix the problem first, like a bad ignition switch if that is it. But using a relay will keep you running at full power, even if some contact or wire somehow somewhere creates a little resistance.

I use new wiring harnesses and soldered contacts etc, but I like the full 12 volts and or 14.2 etc that cool gets from full regulated power...

Starts every time...:nerd:

Cost, a relay, a diode and a few connectors:nerd:


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## PontiacJim (Dec 29, 2012)

lil65gto said:


> Thank you...lots to look at here i guess. Easiest thing would be to just find another switched source to splice into...lol


HMMM, just thinkin' again. You did not say which wire on the ignition switch you hooked to and I did not ask. LOL So let me try this again.

If you connect the white wire to the ignition switch "start" wire, the voltage will only show up when you turn your ignition key to the "start" position - it only sends current down the purple wire to activate the starter to fire up the engine. Once the engine fires up, you let the key snap back to the "run" position and the 12v running through the "start" position on the key shuts off (otherwise your starter would keep spinning when the engine was running).

One of the wires found in the plug that goes into the back of your ignition switch will be the "run" position/hot wire and should have 12V coming out of it. This should be the wire you want to tap into for continuous 12V power (which may be the red wire on the plug). Use your voltage tester to find the 12V (hot) power wire at the ignition switch plug. When you turn your key "on" this allows the 12V power to flow through your ignition system to both "start" and let the engine "run." When you turn your key "off" it cuts the 12V (hot wire) that keeps your engine running.

Now if that doesn't confuse you. So I am deleting my post on the "purple" wire as you need continuous power, not just at "start-up." :blush:


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## Lemans guy (Oct 14, 2014)

Right PontiacJim,......the 12 volt start wire goes to distributor just for cranking,....once started the white cloth covered "Ballast" wire is the run wire which drops voltage to about 9 for running so points don't burn up.

If you have no points, you can run the full 12 volts in fact if you read the Petronix literature it actually recommends the full 12 volts.

The relay can go right on the firewall near the coil and the diode on the drivers side where brown wire is. No need to crawl under the dash to put on relay and diode.....

If you run points you must keep the ballast wire, or a ceramic ballast to drop run voltage.

I don't think one system is better than the other, in fact points gives a nice snappy throttle and start-up and won't usually leave you stranded. However I have had cheap imported "condensers" fail and the car won't run without changing the condenser. .....kinda like changing the module.

But if you have Petronix or HEI you can use full regulated voltage 12 to 15 volts as coils are rated like 8 to 19 volts, so it works good.

:nerd::nerd:


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## Lemans guy (Oct 14, 2014)

Ps some starters have the "R" terminal some don't and there is the purple wire to starter etc...."

Just talking about power to coil...!


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## PontiacJim (Dec 29, 2012)

Lemans guy said:


> I had a bad ignition switch do exactly that on my lemans. Changed the switch and back to normal. But I also wanted to get 12 volts to my distributor since I put in a Petronix instead of points. An easy way to do this is to take the white "ballast" run wire, and connect it to the 12 volt start wire, I spliced them with a crimp,solder,shrink butt connector.......
> 
> Then run a wire from that to the switch contact on a 12 volt relay. You then run a solid regulated 12 volt power source to the relay hot...and from the relay out to your coil.
> 
> ...




Ah, sounds too much like rocket science to me. :yesnod: Sounds like a good solution, but, I think a pencil drawing, however crude, might really help here (at least me, anyway). I am trying to picture this myself in how you got it set-up, but my feeble mind is struggling to imagine how this all goes together - "This then works this way,...your start gives the relay switch 12, your run gives the relay 9 volts or so,...but the relay will close at about 5 volts and will stay closed with about 1.5 volts........but all the time will give full regulated power to your coil through the relay...and spark of course." 12, 9, 5, & 1.5 volts????? 


Will this work on most year cars?
Will this only work for HEI or electronic ignitions/conversions?
Maybe some pictures too of your relays/connections?


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## Lemans guy (Oct 14, 2014)

You are right PJ it does sound like a mess....!

So let me see if I can make it better, can't get a diagram at the moment....

So the wiring harness has 3 wires that come out....a purple wire to starter solenoid......and two others to coil one is a cloth covered ballast wire

For run, about 9 volts,...the other forget the color but is the full 12 volt start wire.....

So when you crank all the way over the full 12 go to coil...when you let go to run 9V ballast wire takes over So points don't burn up.

So if you don't need the 9volts and want 12+ al the time, you take those two wires off the coil + and strip and twist the ends together....

Right behind the coil on firewall mount a relay, which has 4 wires....a ground to a screw in firewall,...one a switch that activates the relay...

And 2 others that are full power in and out...the high power you are using the relay for....

Take the 2 twisted wires and with a female connector attach to "Switch" wire of relay. That activates relay.

Then from a regulated 12v source ......connect a wire to one side of the relay,...and the other side of relay to coil....

Now when you turn the key, the 12 volts from the start wires closes the relay.....the powered relay goes direct to coil full regulated power...

When you release the key, the 9 volt ballast wire takes over to the relay switch..still way more than enough to close the relay......

If the relay is closed then full power goes to coil, it does not matter that 9volts holds it closed or even 2 volts, if it is closed full power to coil.

So it is more power and very forgiving.....you must splice in a diode in brown alt wire, real easy.....

Sorry I can't draw you something right now, but is basically splicing a 12 volt relay, ...(make sure you use a relay that has no internal ballast drop.....).....between the coil and ignition switch but at the firewall where it is much easier to do....

Don't mean for it to sound convoluted, my apologies:nerd:


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## Lemans guy (Oct 14, 2014)

Yes it will work on HEI Petronix, but cars originally HEI won't need it as they did not have a drop to 9 volts.

Some cars have a ceramic ballast on the firewall, corvettes, and you can connect there and just eliminate the ballast, or you can trace the ballast wire to the firewall and eliminate it there and connect it to the 12 volt source there, or do some work under the dash splicing at the ignition switch, or run 

wire that has no ballast drop.....

But the relay is real easy to do, does the same and better as any resistance in that switch wire that develops, from wire contacts vibration would have to get awful low for that relay not to give a full 12 to 15 volts...

As 8 said the relay switch will close at about 5 or 6 volts and it only takes 1.5 volts to keep it closed....

It is an easy install if you don't like pulling out the connectors at firewall and under dash stuff.....Petronix even recommends it, if you don't want to do all that other stuff.


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## lil65gto (Jan 19, 2017)

PJ, I don't recall the color that I spliced into with that switch but it supplies power when turned "on" or "acc" and during "crank" (I will look tonight when I get home).

LG, I have a Petronix unit installed in my original points-style distributor

This is a 1967 Lemans that originally had an OHC6 (now a 400) in it. I don't recall seeing any ceramic ballasts anywhere.

Thanks again...I will jump into it tonight and see what kind of damage I can do!


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## Lemans guy (Oct 14, 2014)

so PJ asked for some photos....here is the relay on my firewall.....

the blue wire is what switches on the relay. it is attached to the white cloth covered ballast wire and the run wire which is black with white stripe....

they both originally had been hooked to coil positive....now switch on relay

the green is just ground for relay to a screw..... the red wire goes to "regulated power"...

the yellow wire then goes to coil Poitive. a diode is in the brown wire from alt that goes to dash light, it is in my harness where the white line appears above the bus bar.

I use the MAD Electrical system plan, Mark Hamilton at MAD is a genius on this stuff...but if you don't have that normally regulated power is available at the Horn Relay positive terminal....

so a car that was originally points can go to full 12v to coil easy this way and go back to points easy be taking out the relay and diode and untwisting the two wires, Ballast and run and hooking them back to coil

if you run an MSD box you don't need it as the MSD box internals basically do the same thing and provide full power out on their big wire...

and the switch wire in does not need much,...same as a relay really for that effect..

cars originally HEI don't need it....but if drop an HEI or Petronix in a original points car this is a little better than letting run on 9v, they still work but the margin for just a little resistance is slight.

so I hope that helps, just a standard 12v 30 amp relay with no internal resistor


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## Lemans guy (Oct 14, 2014)

can't find a way to rotate those images.....yet

just standard relay like this...didn't use the center pin.....


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## lil65gto (Jan 19, 2017)

Lemans Guy,
Can I do this, for simplistic reasons (I will never be an electrical engineer):

1) Acquire a relay
2) Run a wire directly from the battery, to a leg on the relay
3) Run my current switched power from the ignition switch to the relay (This is the one where I'm getting low voltage on 'Cranking')
4) Finally, tie my white wire (running my fuel pump) to the relay.
This would give me my solid 12v power that I need, correct?

I've read this elsewhere and cannot believe it would be this easy?


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## Lemans guy (Oct 14, 2014)

Lil65.....No not exactly,....you must tie power to the relay to "Regulated Power", not straight battery power.
The reason is the coil has to operate with That when the car is going. The "voltage regulator"is either external or inside your alternator grabbing that power is what you want for any thing like a coil.

You have to first find and fix that voltage drop,..then make changes, but if you are running an elder
Trick fuel pump you may want to call Mark Hamilton at MAD Electronics,....just google it and get his kits. They take care of all that stuff, and make the system very reliable and powerful.mfrom strong headlights to reliable start-up. If you are not going for total originality, and want real bright lights and full power to all systems his full power kits are really great. 

You are paying for his knowledge but his wiring is superior stuff he has special made even the wire cover is thick with high heat resistance..

Just Google him and call him,....tell him a guy in Tennessee told you to call!


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## PontiacJim (Dec 29, 2012)

OK, turned these around for a better view.

lil65gto - "I have a Petronix unit installed in my original points-style distributor"

PJ - I assume you are not using the factory resistor wire and have run a jumper wire? You need 12 volts when using this conversion. 

If you are still using the factory wiring, you get 12volts when you hit the "start" and then your points will run on the resistor wire when you snap the ignition back to the "Run" position. The resistor wire gives lower voltage so the original points do not burn out. Lemans Guy's set-up will take care of this and give you the 12V you need if you don't already have it.

Just checkin' :thumbsup:


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## lil65gto (Jan 19, 2017)

PJ, no...I did not remove any resistor wire. It is my understanding the original Petronix did not require this (Petronix 2 did?). 
I pitched using a simpler Lemans Guy resistor idea to do a quick elimination of my voltage issue at hand, with the voltage drop with the fuel pump. I gotta say...electronics or electrical isn't my thing. I can do most ANYTHING but I'll send the car down the road if I have to keep messing with electrical...


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## PontiacJim (Dec 29, 2012)

"PJ, no...I did not remove any resistor wire. It is my understanding the original Petronix did not require this (Petronix 2 did?)."

OK, not sure. I used a 12 volt jumper wire on mine (the first version of the Petronix conversion). But, I found this on one of the threads, "Feb, 2006 - Called Pertronix today, was told that their coil (Flame Thrower) needs 12volts to work properly so no resistance wire. If it's an OEM coil use the resistance wire and if you are using an later model coil it probably will need the full 12 volts."

I used a hotter coil than stock. It may be worth an email/call to confirm this. Don't know if you still have any directions? There is a PDF online that shows ways to hook the distributor up along with the resistor wire in place by using a jumper wire, but don't know what version this applies to although this looks like the original conversion: http://www.pertronix.com/docs/instruction-sheets/1141.pdf


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## Lemans guy (Oct 14, 2014)

Petronix guide as PJ attached says A ....the recommended wiring...12 v.....B alternate, use ballast....

It still works with a ballast or ballast wire that drops v to 9. But leaves little margin for error.

Coils run at 7 v to 16 or 18 v.....with points you had to have 9V, with Petronix you can have 12... with 9 just a little resistance can drop you down to breakdown.....

Resistance comes from 1) old dirty brittle wiring. 2) heat in the engine compartment, heat = resistance, ( that is why guys starters don't work good when close to exhaust manifold, that is why they sell starter heat shields, the heat puts resistance in the copper wire windings of the bending)

3) vibration, which all cars have that can loosen a contact.

All those = resistance, the relay just lets you take full advantage of Petronix, gives full regulated power, 12 to 15 volts to coil.

And since the relay will close at about 6 volts and stay closed with 1.5 volts you flip the electrical equation to your side. Resistance from any factor would have to get awful low for a breakdown. And relay are very reliable.

Also you can run Petronix with a ballast. Lots of guys do and tell you they have for years no problem. But that mean it is ideal.

We all know the guy who says I never change my oil and my old truck runs great, been doing it 25 years,...ok well there you go. It works maybe just not ideal and he may be headed for a breakdown,..

Lil got to find and fix the voltage drop first, ...likely, ignition switch, voltage regulator, or wire with high resistance, rusty fuse holder, old fuse

Fix that first and then consider relays or not......:nerd::nerd:


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## lil65gto (Jan 19, 2017)

Thanks guys. To eliminate my immediate problem with the fuel injection pump, i installed a toggle switch and the car fires right up now. Not the fix i wanted but it'll work temporarily. I am currently digging into my engine side resistor wire, to hopefully replace it. Coil to firewall connector. There is 2 wires that go to my (+) coil that comes out of the harness. One is vinyl covered and the other is the fabric covered. I will remove the fabric covered wire altogether and replace with a standard 14-16 gauge wire. Fingers crossed here.


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## lil65gto (Jan 19, 2017)

Success. I removed the resistor wire...well, i actually left it in the harness and ran a jumper. Hardest part was removing the pin from the firewall plug (thank goodness for a spare gm wiring harness hanging around). Coil now registers 12.5 volts when key is turned rather than 9 volts. Unless I'm imagining too, the car seems to idle better.


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## PontiacJim (Dec 29, 2012)

lil65gto said:


> Success. I removed the resistor wire...well, i actually left it in the harness and ran a jumper. Hardest part was removing the pin from the firewall plug (thank goodness for a spare gm wiring harness hanging around). Coil now registers 12.5 volts when key is turned rather than 9 volts. Unless I'm imagining too, the car seems to idle better.




Sounds like success. The car probably does idle better as you needed the12V for the Petronix conversion - you are probably getting a better spark. :thumbsup:

I wonder if you could now use a relay ( one wire in, two wires out) and then split one wire off to the coil and the other wire off to your fuel pump. Would think this would work off your key and eliminate the toggle switch. No expert here, but just thinkin'. Lemans guy may have the solution for you.


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## Lemans guy (Oct 14, 2014)

lil65, super that is a perfectly valid fix, eliminate the cloth covered ballast wire and run full 12v to coil.

As PJ says it likely is idling a little better as that Hall effect sensor of the petronix switches off the electro-magnetism......so nice strong signal nice crisp switching....

points does need that as it is a mechanical switch.....like we said petronix will work...just works better with full voltage.

as far as full pump, not sure if you have the pump in the fuel tank, some put them close to engine but can cause other heat related vapor lock problems.

If it is in the fuel tank and your voltage drop problem is there it may be the length of wire that drops the voltage,.....the longer the wire the more resistance.

So a good solid regulated voltage to the fuel pump is also needed. If you have to run a long wire for full power you may want it a little larger, say a 10 gauge to run from engine compartment to rear of car. that could be used as the power shot for a relay, the switch wire for the relay could be the wire you have now.

For example I use MAD's system and have a strong wire, (10 gauge, if I recall,) to a buss bar in the trunk. there I can get direct full regulated power to anything. I do the same up front and have all my headlights on Relay's.

the line from the buss bar is short to the relay, the relay switch wire is long and thin...the original wire that goes to the headlight switch and around under the dash and back up the front of car. All that wiring is a recipe for 
Dim Bulbs!

Nobody wants to be a Dim bulb.... but you have done great Lil65, that coil will be sparking, nor the relay is just one way to do that where you don't have to get into that front wiring harness and all those related issues.

On these cars the original place for regulated power was the positive terminal of the Horn relay. so that would be a place to connect and run a 10 gauge wire back to trunk or rear of car if you wanted to relay an in tank fuel pump.

if it is in the engine compartment it could still be done.

anyway, I am no electrical expert, just like you guys always trying to make it a little better more reliable. I refer you to Mark Hamilton at MAD Electronics, 
He is the expert.

PS the original sytem can work fine if you maintain it carefully and keep wiring contacts fresh, points fresh, dwell set coil good etc etc. It just was designed for about a 7 year life, and manufacturing processes had to be fast and cost effective as well.

That is why the "Buss Bar" in your GTO is a three wire splice in the wire harness. Works OK but hard to add stuff to, like an electric fuel pump or electric fans, or even a relay for brighter headlights.

I say good work on your part and PJ's advice is always solid as is the crew here that just try to keep us all moving!

PS i still love Points might put mine back In!:nerd::nerd:


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## lil65gto (Jan 19, 2017)

Kind of nice when the car operates as intended. Thanks again everyone!


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## lil65gto (Jan 19, 2017)

Just as update, I have found two issues that might be related to that voltage drop issue. 

1) My ignition switch connector seems to be melted where it connects to the switch itself (brown wire). Just to eliminate any problems...a new ignition switch and cylinder is on order.
2) I had problems with the left brake light not working. Then my RF parking light decided to quit. WTH? It wasn't a ground issue as I could get them working for a split second by tugging on the turn signal switch wiring at the base of the steering column. I then ordered/received a new Delco switch, tore everything apart and realized I needed the Boyne-style switch. On order now. BUT, my wiring harness going up the steering column had several areas where the wire insulation was worn pretty bad.

Here's to hoping and will give an update!


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## lil65gto (Jan 19, 2017)

Just another update (so anyone searching with a similar problem can see my solution).
I replaced the turn signal switch. I was a little wary as I had never jumped into one of these before but it's not very difficult at all. The hardest part (which was easy) was removing all the pins from the arched clip so I could slip it through the column.
After removal of the old switch, the wire insulation was worn right off in a 3 areas so I'm sure things were grounding out and causing mayhem with the electrical. I cannot believe how many different circuits actually go through this switch! 
My brake lights, turn signals, interior lighting...everything cleared up. Best $85 spent!


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## Lemans guy (Oct 14, 2014)

Great work...perseverance pays off!


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