[gtoformula]

A buddy of mine is restoring a 1970 GTO that he says is equipped with a backglass wire grid defroster not the blower motor type). He has the backglass in the car, but is missing the switch that mounts in the instrument panel. Anyone know (or have one) of these switches?

[gtoformula]

A buddy of mine is restoring a 1970 GTO that he says is equipped with a backglass wire grid defroster not the blower motor type). He has the backglass in the car, but is missing the switch that mounts in the instrument panel. Anyone know (or have one) of these switches?

[lawbreaker2]

I do.

[gtoformula]

Lawbreaker2 - is the switch in your car or do you have one that you would sell?

[lawbreaker2]

No, it"s in my car. I heard it is not that rare for the defroster in these cars but I did not know they had two kinds of defrosters.

[CDN2PLS2]

The one with a fan is a defogger,the one with a grid is a defroster.

[Brutus_5150]

I don't know if it makes any difference if its a blower or window grid switch, it just transfers power, but I'm wondering if it's a switch by the steering column to the right or on the heater controls itself..

[gtoformula]

The defroster switch is supposed to be mounted to the right of the steering column ... not in the HVAC control assembly. Anyone know where these can be purchased?

[TonySD455]

I posted a similar question today, but I'm looking for the blower style switch for a 73 TA I'm purchasing. I believe for the TA's (probably the same for GTO's) that the grid uses a 2-position (on/off) switch, whereas the blower style one I believe is a 3-position, center-off switch with high and low fan speeds. Can anyone help confirm/correct? I'm trying to find out too.

[Dens71TA]

Yes, Firebirds used a Low/Off/High switch for the fan blower rear window defogger and a On/Off switch with a built in relay/timer circuit for the window grid style defroster. The defrost style switch is different for early firebirds. I'm not sure when it changed but I think it was around 1975.

[Brutus_5150]

I believe F-T/A's had a different switch all together than the goats. I also think grid windows are pretty freakin rare in the 70-72 GTO/lemans.. Look north if you want to find a defogger/defroster switch too...

[TonySD455]

Hey Brutus,

Thanks for the tip. It just so happens that when I looked north, low-and-behold there it was...a rear defroster (uhh, I mean defogger - thanks CDN2PLS2) switch! I can't believe it - I mean, my computer faces south, and so naturally I looked east and west, but I never thought to look behind me (North). Just kidding everyone- thanks for the tip.

[Lloyd-TX]

FYI:

From my Pontiac MPC's: (All PN's are within the 9.778 group)

1970-1972 A-bodies with the blower-style rear "defogger" used switch PN 9799923, and with the grid-style "electric defroster" they used switch PN 479050.

1970-1973 Firebirds with the blower-style rear "defogger" used switch PN 477878; and with the grid-style "electric defroster" they used switch PN 477877 or 494579.

Hope this helps!

[Brutus_5150]

All you had to do was turn your chair around, Tony.
Is your car a 4-gear?

[Steve Barcak]

I have a Defroster in my '72 GTO. It is an extremely rare option here in Az. The defroster/defogger switches in the GTOs are different from each other. The defroster switch has a light in it, the defogger switch does not. I think the light is an amber color. The GPs from the same years used a different back glass but they did use the same switch and it is much more common to find a GP with this option than a GTO. Keep an eye out for a defroster switch from a GP. Steve www.pontiacheaven.org

[Lloyd-TX]

FYI Steve:

Again according to my Pontiac MPC's:

1970-1972 GP's with the blower-style "defogger" used switch PN 9799923, same as the A-bodies.

1969 GP's with the grid-style "electric defroster" used switch PN 9798478, and 1970-1972 GP's used switch PN 479049.

[TonySD455]

Yes, Brutus. Why do you ask?

[rchamberlin]

Can anyone help with a wiring diagram for 70 grand prix electric back window grid defogger.