# Heater fan speed issues



## droptop69goat (May 12, 2008)

Hey troops;

Let's see if Y'All have had this issue;

I recently got (Just about) all the items for my heater and AC fixed/repaired/cleaned up, etc, and there is still one issue that my OCD mind is hung up on.

The car is a 1969 GTO. I have AC.

On the control panel for the heater and ac, in the right side of the panel is the fan speed switch. There are 4 definable positions , and they are labled slow on the left and Hi on the right. There is no "Off" position other than the total off with the main control lever.

When running, I get all three of the speeds from position one to position three.

When I switch to position four; the highest; it makes a click sound, and stops running.

During the process to get to here I have put in a new heater core, fan, speed switch for fan, rebuilt whole ac/heat control panel, cleaned up heater fan resistor, new fan relay on firewall, (which appears to be what is clicking) and etc.......... WHEW!

Has this happened to any of you? What did it take to fix and get all FOUR fan speeds??

HELP........I am in OCD H-E-double hockey sticks now over this!! LOL


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## droptop69goat (May 12, 2008)

Well folks, never mind.....after 49 views and NO advice I managed to figure it out my self.............:confused

For those of you that may have had this issue, I offer the following:

If you lose the HIGH speed on your fan (4th click) and all you hear is a click (the sound of the relay working) you have lost the power from the alternator. It could be the wiring, the 30 amp inline fuse, or possibly bad wiring AFTER the relay not allowing the voltage to make it to the motor.

In my case I have ZERO output at the alternator lug that powers the high circuit. With the key on or running, I have zero voltage at this lug. (on the Right rear of the alternator.)

So now I ponder rebuild it my self, or go buy a new chrome one to replace the one I have now...............................

Hmmmmmmmmm.............

Maybe this may help some of you out...who knows.


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## Rukee (Feb 8, 2007)

That single big wire to the back of the alternator should be connected to the battery, possibly at the starter + terminal with a fusible link.


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## droptop69goat (May 12, 2008)

So..........

Total completion!

I now have fan speed number 4! WOOT! arty:

Turns out there is no other hot post on the back of the alternator, and the wire was in the wrong position....it is supposed to be with the big to the started so there is always hot power to the relay.

Having not always owned the car and finding the wiring that condition I thought it was right....."twas not the case.... You sure learn alot about a particular car when you get a hold of it, both good and bad!

Anyway, I am really jazzed that I now have a fan that 'dern near blows you out of the car on high!


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## Eric Animal (Oct 28, 2007)

CHROME IT !!!arty:


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## joedee (Dec 13, 2012)

droptop69goat said:


> So..........
> 
> Total completion!
> 
> ...


Got a question. That HOT wire going to the relay means it is always energized? When I hook the battery up I hear the relay click. Does yours do that also?

Joe


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## 1970 Lemans (Jul 25, 2009)

joedee said:


> Got a question. That HOT wire going to the relay means it is always energized? When I hook the battery up I hear the relay click. Does yours do that also?
> 
> Joe


From the wiring diagram, the relay is closed from current going through the blower motor 'switch' at the dash. I believe this circuit (that actually closes the relay switch) is distinct from that which provides current for the high power feed to the blower motor. It looks to me like the power for the motor comes from the alt., through the in-line fuse, to the relay, which, when closed, alloys the current to then get to the motor. So, I believe that if you hear the relay close, it does not necessarily mean that you have power to energize the blower motor (at the high setting). You can disconnect that lead to the back of the alt., or remove the in-line fuse, and you would still hear the relay click.

The high setting does not work on my car either. I can hear the relay open and close when I move the switch to the high setting, and the fuse is OK. I am wondering if the relay is faulty (maybe fried from heat?).


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## joedee (Dec 13, 2012)

1970 Lemans said:


> From the wiring diagram, the relay is closed from current going through the blower motor 'switch' at the dash. I believe this circuit (that actually closes the relay switch) is distinct from that which provides current for the high power feed to the blower motor. It looks to me like the power for the motor comes from the alt., through the in-line fuse, to the relay, which, when closed, alloys the current to then get to the motor. So, I believe that if you hear the relay close, it does not necessarily mean that you have power to energize the blower motor (at the high setting). You can disconnect that lead to the back of the alt., or remove the in-line fuse, and you would still hear the relay click.
> 
> The high setting does not work on my car either. I can hear the relay open and close when I move the switch to the high setting, and the fuse is OK. I am wondering if the relay is faulty (maybe fried from heat?).


Thank you for the reply. I will have to try it with the 30 AMP fuse out and see if the rely clicks when I hook up the battery.

Thank you,
Joe


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## ajluzi1957 (Mar 22, 2017)

Good afternoon All,

I have been through similar issues that were described above after getting my car with bad wiring from a previous owner. After going through the wiring diagrams and fixing a couple of things that I found to be wrong, I now have all fan speeds.


My issue now is what Joedee described. The relay appears to be energized all the time. I can hear it click when I remove and reconnect the battery cable. Per with wiring diagram, there is a wire coming from the alternator to this relay that is live from battery voltage when the car is off.

Problem now is that after a few days, the battery goes dead. I measured the current draw with nothing on in the car and this relay is drawing 250MA, which is quite a bit.

Should the relay draw that much? or could it be bad?

I would think that the relay should use switched power, then it would work perfectly, but it is wired correctly (Black Double Orange from alternator pin to relay)

Any thoughts would be appreciated.

Armand


Does anybody know if this relay is supposed to draw that much?


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## ajluzi1957 (Mar 22, 2017)

Forgot to mention this is a 1969 pontiac Tempest with Factory A/C


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