1970 GTX rear defroster install

[Mark Pifer]

Hello, I would like to install a rear window defroster in my 1970 GTX.
1. Does anyone have this option on their GTX or Roadrunner?
2. If you do where is the defroster on/off switch located.
3. Do you have a photo or diagram showing the switch location on dash board and blower unit under deck in trunk?
4. Would you have the part numbers needed to do a complete install of the defroster unit?
Thank you for anything you can share.
Regards,
Mark

 

[PurpleBeeper]

First, I will say I'm not sure.... so take this with a grain of salt. For a 70 GTX, I think the rear defrost on/off switch is exactly the same as a 70 convertible top switch with the toggle installed backwards. Those toggles say "top" (?) on one side and "defog" (?) on the other side. I also believe the defroster mounts in your back package tray in one of the rear speaker holes.

 

[HawkRod]

I added a rear defogger to my 70 Road Runner (it did not have one originally). The right rear "speaker" hole is actually a hole to mount the defogger unit. Since I wanted two speakers I mounted the unit in the trunk instead with a 6x9 speaker grill and it pulls air from under the back seat. Not ideal by any means, but a way that I could still have two speakers with the defogger. The defogger unit, hose and vent are fairly standard. I don't remember the specifics for mine, but I think many years will fit and work.

As far as the switch: I made my own switch that is hidden under the dash. I would prefer an original, but they are hard to find.

 

[Under Pressure]

First, I will say I'm not sure.... so take this with a grain of salt. For a 70 GTX, I think the rear defrost on/off switch is exactly the same as a 70 convertible top switch with the toggle installed backwards. Those toggles say "top" (?) on one side and "defog" (?) on the other side. I also believe the defroster mounts in your back package tray in one of the rear speaker holes.

This is correct, my 70 GTX came with this option, I am stopping by this week where I keep the car in storage and can get a pic of the switch if you need

 

[RJRENTON]

I posted this in the other section.....
I have this option installed on my RS23V0A******. The on/off switch is immediately to the right of the heat/defrost control system and recrives its power from the same source as the heater fan. A better solution may be to have the rear fan operate when the heater fan receives power, for total air movement. The center of the rear parcel shelf is where the outlet located to blow air directly on the rear window. The system air inlet is located to the right side of the the rear parcel shelf and the inlet looks like a rear seat speaker, ~ a 6" x 12" opening. A short piece of flexible (1-1/2" diameter x ~12" long) defroster fuct hose connects the fan's outlet to the defroster distribution nozzle. The system just recirculates interrior air to the rear window.....there isn't any heat source involved.....just re-circulated air. How good is the system ??.....its OK....marginally better than nothing. No pix...The car is in storage for the winter. Hope this helps......
BOB RENTON

 

[Mark Pifer]

Thank you so much for all the great information. I thank you too for planning to send photos of it later this week.
Best Regards,
Mark