Help with heater needed
 

OK, someone PLEASE help!!!! It's starting to get cool in the morning here in the mountains, and I've got no heat/defrost. I drove to work today like my dog...head out the window!!!

First pic is my fuse block, note the good "heater" fuse

Attachment 500870

Second pic is of the firewall terminal, and the 2 wires I have in querstion...

Attachment 500871

Third pic is that #2 wire labeled in the previous pic, but it's never been attached to anything...where does it plug into? it comes across the firewall to the passenger side, then down with a purple and yellow wire that both run the the starter (bendix?)

Attachment 500873

Fourth pic is where the #1 wire, terminates after running across the firewall with the #2 wire, and the above mentioned purple and yellow wires. What needs to happen to this wire?
Attachment 500874

Last pic is the wiring on the heater core under the hood...

Attachment 500872

I found a plug on the side of the heater controls in the dash...it's all plugged in and wires are good.

Also found a plug under the glovebox, one wire is the above shown orange wire that runs to the heater core under the hood...that plug under the glovebox is all plugged in and wires are good, too.

The manual I have has nothing about the actual heater wiring, so if anyone can help...please do.

Thanks,

Re: Help with heater needed
 

#2 wire is for an oil pressure light setup and would have hooked into the block behind the distributor.

#1 wire is for the engine temperature and was probably a "hot" light hookup.

Starting at the heater motor make sure it runs by connecting a 12 volt jumper wire to it.

If the motor runs then check for power at the heater switch, before and after. If no power at the switch recheck the fuse holder connections. From your picture it looks like there is a corrosion problem with the contacts. If power is going through the switch check the resistor block and wiring.

Jim

Re: Help with heater needed
 

Thanks Jim, I'll check it out...really appreciate it!!

Re: Help with heater needed
 

hey slate, look and make sure that your heater control cables are all connected and moving freely, they can bind up and stick.

Re: Help with heater needed
 

Might also check that ground strap on the fan motor.

Re: Help with heater needed
 

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The A/C fuse also has to be good for the heater to work. At least it did on my '71 4x4...

LockDoc

Re: Help with heater needed
 

Thanks guys...the ground needed to be cleaned up. Now it's either on or off, that means resistor right? and is the resistor under the glovebox? How do I get at it?

Re: Help with heater needed
 

Can you feel the three positions in the switch when you move the lever? I have seen more problems with the switch then I have with the resistor. Removing the glove box will help you in getting at the resistor.

Jim

Re: Help with heater needed
 

Yeah, you have to take out the glove box liner to get at the resistor. They're available on-line. When the blower motor resistor went on my '95 astro, I had only off and high speed for the blower. It could still be the switch but my bet is the resistor.

Re: Help with heater needed
 

Don't for get to check the blower motor resistor mounted inside the truck in heater plenum, access it through the glove box is easiest. This reduces voltage to blower motor to vary it's speed...the part inside the plenum looks similar to light bulb filaments on larger scale, these are apt to break causing no power to get to blower motor...they reduce voltage by producing heat...the heat/ cold cycles lead to its demise. It is attached to the heater plenum by 2 small screws or bolts and has a wiring pig tail with like 3 wires in it I think.