AC blower motor wiring help. 72 Runner

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

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sco440
Satellite Coupe (RL)
Posts: 2
Joined: Sat May 16, 2015 9:53 pm
My Cars: 1972 Plymouth Road Runner

AC blower motor wiring help. 72 Runner

Post by sco440 » Sat May 16, 2015 9:57 pm

My question pertains to my AC blower wiring. According to my FSM p. 8-154 there is a green wire C5-14DGN attached to the air conditioning motor (assuming this is the blower motor). I have a green wire with a grey plastic boot plug plus a ground on the engine bay side of my blower. The FSM says this wire goes to the # 4 spot in the bulkhead. I am I reading it right? This powers the blower motor? When I hook it up like this I get nothing from my blower switch. What am I doing wrong?

71Satellite98661
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Re: AC blower motor wiring help. 72 Runner

Post by 71Satellite98661 » Sat May 16, 2015 11:46 pm

Assuming the 20 amp fuse is good and the blower motor ground is good, I'd check the following. Fuse output to the 5-terminal block on the control switch, the output from there to the blower switch connector, from there to the resistor block on the passenger side plenum, then from there to the to the bulkhead connector you described earlier and also out on the engine side of bulkhead (that connection is most likely to losen or corrode). You could work in reverse of its easier. Have you tested the motor with a jumper from a 12V source?

sco440
Satellite Coupe (RL)
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Joined: Sat May 16, 2015 9:53 pm
My Cars: 1972 Plymouth Road Runner

Re: AC blower motor wiring help. 72 Runner

Post by sco440 » Sun May 17, 2015 8:59 pm

THX, it seems to be in the high med low blower motor switch. Got the blower to work by jiggling the switch but only on high level with ac lever on max. I have no med or low blower levels. Took the switch apart and cleaned terminals, no change. Do they go bad?

71Satellite98661
GTX (RS)
Posts: 280
Joined: Sun Apr 21, 2013 7:14 pm
My Cars: 71 Satellite
70 Challenger
07 300C SRT8
13 Ram C/V (Caravan) work-issued
Location: Vancouver, WA

Re: AC blower motor wiring help. 72 Runner

Post by 71Satellite98661 » Tue May 19, 2015 10:41 pm

A faulty switch sounds reasonable. There are a couple of new ones on eBay now.

http://www.ebay.com/itm/1971-1972-Dodge ... 1305534069

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