Heater/Defroster

Technical Question and Answer - On topic to 71-74 Plymouth B-bodies only.

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beepx2

Heater/Defroster

Post by beepx2 » Wed Jan 16, 2008 6:39 pm

Hey all,
I've got a '71 RR non ac car. It has the StratoVent option. The problem I'm having is with the heater/defrost door. It doesn't seem to be opening. I know the cable from the switch on the control panel is connected because the door to the dash vents open when I move the switch to "vent". When I put the switch to heat or defrost, nothing seems to happen. Is the heater/defrost door controled by a vacuum like the vent door? Anyway, what must I do to check and/or fix this .
Thanks.

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JosephGiannini
GTX (RS)
Posts: 130
Joined: Tue Oct 21, 2003 9:40 am
My Cars: 1972 roadrunner 340 4 barrel with 727
Location: washington dc

enviromental controls 1971-1972 ssp s rr and gtx

Post by JosephGiannini » Sun Mar 09, 2008 8:14 pm

what happens is the ecu is all vacuum operated no surprise there
rubber and plastic cure overtime and dry rot.
sadly to say there is no stop to this even oem prior to abs plastics
yellow become brittle crack and are of no use for vaccum you can try to replace the switch with oem is you wish however last ones made where in 1974 that you need making it 30+ years that is some aged plastic
there are 3 lever vaccum pod actuators one drivers side two passenger side one controls defroster one controls vent and one controls floor heat
i have replace my unit will all new switches from www.surplussales.com
I own a 340 850hp Dick landy industries spec engine god rest his soul.
A Mopar god Is dead.
1972 roadrunner.

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rr6pak
GTX (RS)
Posts: 1007
Joined: Sun Jan 30, 2005 10:29 pm
My Cars: 1971 Tor-Red RR
Location: USA

heat

Post by rr6pak » Mon Mar 10, 2008 12:27 am

J Giannini...What swithes are you talking about? Does this surplus store have them? Do you have a pix or P/N?
Thanks

beepx2

Post by beepx2 » Mon Mar 10, 2008 11:49 am

If I could just get them opened, I think I would be satisfied with that.

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