# rear windows defogger gto 1966



## Franckh (Apr 12, 2020)

hello Friends of the gto 🤘🤘.
I'm looking for plans and diagrams of wiring and installations for rear windows defogger. because not found on the internet. 
The French 🥐


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## GTOJUNIOR (Aug 7, 2011)

There really isn't much out there; Attached is a page from the service manual and some images from my '66 showing the layout.
Switch power wire runs across to the passenger side and along the transmission tunnel to the rear shelf.
Shown in image 3 are the wire routing and the rear seat wire cover/protector.
The fan unit and grill can only be installed on the driverside of the package shelve.
Retained by the 3 bolts/nuts of the grill. The plastic diverter is shown ( GM Box) and is needed for optimum air control.

These fans really don't do much but they are a neat little gadget 
Hope it is of some help.


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## Franckh (Apr 12, 2020)

Thank you for your answer 😉. Where can find rear window defogger because don't exist in France 🤔


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## GTOJUNIOR (Aug 7, 2011)

You'll likely have to run a parts wanted ad and/or look for a good used one on-line.
Cheers.


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## Sixty7GTO (May 4, 2017)

How does the fan operate with two speeds and have only one wire feeding the motor? There must be another wire up at the control switch that has a resister in it ?? Can someone tell me how you get the drop in voltage to run low speed. I can't find it in the wiring diagram. If it's already there I'd like to use it. My control switch has a brown, a light green, and a remnant of a broken-off wire with no color, just a bare that's still attached to the third terminal of the switch.


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## GTOJUNIOR (Aug 7, 2011)

IIRC It's a basic resistance/capacitor type switch to control Hi-Low.


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## O52 (Jan 27, 2019)

Of the three switch wires, one is the 12 volt feed wire. Of the other two wires leaving the switch, one is a resistor wire similar to the one for the ignition coil. This resistor wire is for the low speed. The other for high speed. 
Depending on year, the resistor wire may be from the switch to the rear harness plug or after the harness plug and as part of the rear harness. These two wires splice together before or after (depending on the year) the plug. 
After the splice it is one wire feeding the fan. 

Photos are from a 68 harness. Purple wire with plug is the fan end.
Purple and white wires are at the dash end. Cloth covered white wire is the resistor wire.


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## GTOJUNIOR (Aug 7, 2011)

A much better description.
Here is a better pic of a '66-'67 switch/wiring showing the two into one factory splice.


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## Franckh (Apr 12, 2020)

Good evening
Sorry for the translation (google)
yes, there are two wires of different cross section. This is what makes the engine speed as in the photo


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