Steve, I'll take a look tonight and let you know.

 

Ok, on my wiring pigtail from the switch, the orange wire goes to the fan. Then on the fan there should be a black wire. Ground the black wire.

I am a little confused on this. I traced the below on my buddy's '72. Some of the wires in his overall harness were different colors. So take this for what it's worth.

My pigtail is shaped like a "T." I have one of each of the following colors...
Orange> Fan
Brown> Power from fuse block
Red> Hot when key and heater switch is on
Light Blue> No idea (could be the black one mentioned below)

The wiring diagram I have does not cover the heater in detail. Here is what it does cover.

Brown starts at the 20 amp fuse in the fuse block and runs to the heater switch. That matches what I found above. Then it mentions a black wire. I don't have this. The black wire goes to the windshield wiper switch. Don't know if you are familiar with how the ws wiper switch pigtail looks like. On the ws switch there is a pigtail with 5 female ends. That harness comes from the windshield wiper motor. Then there are two other male connectors on the back of the wiper switch. According to the diagram, the black from the heater switch goes to one of the two male ends. The other from the wiper switch is also black but it goes to the windshield washer pump.

I will email what diagram I do have.

Hope I didn't confuse you!

Bryan

 

step side,

I removed the two bolts that are on the side of the heater assy that hold the pirtail on there. Inside i found the resistor. I am guesing that the fan will work just fine with out the resistor, I just would not have speed control correct? I do not have the dash control unit anymore because the dash has been redone for racing. But I guess if i wanted to use speed control since i do have the resistor i could use a three way switch???

What do you think?

Let me know.

Steve

 

Steve, I'll bet the reason why I had no speed control is that I am lacking the resistor. What wire is it attached to? I would think your three way switch idea would work for off, low and high settings. Let me know on the resistor placement. Thought I had a bad switch or some other wire was hacked like the rest.

 

The resisitor is bolted with two little bolts on the side of the blower housing. The wires for it is a pigtail that has several wires attatched to it, being the red, orange, blue, and I guess a brown from the dirty colors. Then the end of that pigtail is what I think plugs into the control assy.

Hope this helps you too, I'm not for sure it my resistor is bad or not but I know you can get them through restoration catalogs for decent prices.

 

I just figuered it out stepside.

The pigtail that plugs into the back of the controler wiring is like this for the speed controls if you want to know. orange is high, blue is medium and red is low, the brown wire there is for power to the switch.

hope this helps you out, im on the look out for a four way switch.

thanks

steve

 

Ok, so I do need the resistor. The only wire that was connected on mine was the Orange. That is why I only had High! Is there a part # on your resistor? Or can you post a picture? Two heads are always better than one. Thank YOU for your help too! Check out www.blueovaltruckparts.com for the switch. I know I have seen them there, just can't remember the price.

Bryan

 

stepside,

I could not find any part numbers on the resistor, but if you are still looking for it, it is on the side of the blower bolted with two small sheet metal bolts. be careful when you take it out mine ended up braking the non conductive plastic stuff but it is still ok. thanks for that link lmc has some good stuff two, you just have to wait on the catalogs.

thanks

steve

 

put the heater back in and got it all powered up and heater hoses running to it now. WOW that thing really has some heat output and blower power, I am so glad I decided not to sell it on ebay.

just letting you know

 

Steve, I haven't gotten a chance to look yet. I had to work on the '99 this weekend. Thanks for all of your help. I have a feeling that the resistor is not there. I'll look better as soon as I can. I am doing the babysitting thing at night now. Put the wife to work so I can spend more $$$ on the trucks! Just kidding! LOL!

 

Steve,

I finally got a chance to look the heater over really good today. I don't have any resistor on it. The black and orange wires come right out of the fan itself. No sheet metal screws. Could you email me a picture? Does anyone know the technical name for the resistor we are speaking of so I can shop for one?

Bryan

 

So what was at the other end of those wires that go to the heater motor?

The heater resister should be at the other end .

 

The black wire on the fan is ground and the orange one is for power in. That should have plugged into a resistor block that has two resistors. The switch has one wire for power in and three wires for power out. These three wires go to the resistor block. It switches power to the resistors such that on low speed the current goes thru both resistors, mid speed only thru one and high speed directly connected to 12 volts. These resistors get hot and that's why they're mounted in the airstream. Sorry I don't have a diagram with wire colors but that is the way the system should work.

 

If I coud get my damn scanner to work again, we would have solved this one ages ago

 

Ok, so they are inside the case for the blower motor?