Factory A/C & Heater Help
 

Turned on the A/C the other day and started getting a bunch of smoke from under the dash. Figured it was probably the electric switch on the controls so took it apart and found a few issues. First picture shows the burned up switch, second picture shows burned up compressor clutch wiring, third picture shows the high speed blower relay, forth picture shows the outside of the blower motor assembly with a mystery hose that's cracked.

http://img118.imageshack.us/img118/304/dsc00144sa1.jpg

http://img118.imageshack.us/img118/2209/dsc00146tv9.jpg

http://img118.imageshack.us/img118/317/dsc00140py5.jpg

http://img516.imageshack.us/img516/7900/dsc00150uh3.jpg

Two questions, first of all, should the relay be mounted to the firewall, or is a remote ground sufficient? Secondly, what is the hose in the forth picture, and where can I get a new one? I haven't been able to find anything online about it, am I going to have to just get a plug fitting and new hose? Anyone know what it's called, and what it's for?

Thanks,

Re: Factory A/C & Heater Help
 

The relays are normally mounted on the inside heater box with a remote ground so what you have should work.

The hose pictured is to circulate air through the blower motor. From looking at the picture it does not look too bad. Does the blower motor have a hole in it for the flanged end of the hose?

Jim

Re: Factory A/C & Heater Help
 

Re: Factory A/C & Heater Help
 

Thanks for the input guys. Jim, the hose is actually cracked, it looks like from the picture that the hose is still somewhat intact, however it's actually broken off and the molded end (flanged end) is still in the hole in the blower motor. Anyone know where I can track a new one down? As far as the wiring, I think that I'm going to create a dedicated ground somewhere on the firewall, because I think that's what led to the whole burn up.

Re: Factory A/C & Heater Help
 

Looks like your missing the 4th wire on the AC switch too. That give you your low, mid, high setting. I have the ac wiring diagram on my pc at home.

I might have a good hose at the house, i'll look when i get home. I'll drop it in the mail for yah if its good.

Re: Factory A/C & Heater Help
 

Another reason to replace my A/C wiring harness.....

Re: Factory A/C & Heater Help
 

Appreciate the help Jay. Yeah, I think you're right about the 4th wire. I need to check out a diagram and go from there. Definately one reason to completely go through the wiring in these oldies and update. Thanks for the help guys...

Re: Factory A/C & Heater Help
 

BTW, anyone know of any good online places to get wire pigtails for older style switches like in our trucks? i.e. 4 pin A/C control switch, 2 pin Compressor clutch, etc. I'd like to put all new connectors on these and would prefer to use factory style rather than just spade connectors and electrical tape.

Re: Factory A/C & Heater Help
 

Well i didn't have the motor cooling hose, but heres a diagram.

Re: Factory A/C & Heater Help
 

Here is what I would do (and actually did do a few years ago):
First I ordered a new switch and a new plastic connector for the back of the switch from LMC. Folks here hate LMC. If you don't like them find a board sponsor and see if they carry these pieces. I didn't have to order the 2-pin compressor connector so I don't know if they are available. If not just go to the junk yard and clip one off a donor. Then go to NAPA and order "type 56" connectors. At NAPA they won't know what you are talking about so just tell them you want 20 or so pieces of part number 725147. The male side of that connector is 725145. You may as well grab some of those too. Buy extras because most of the connectors in your truck have this brass colored insert for the actual connection. I keep a handfull of both around my shop. Then go to Lowe's, Home Depot, Menard's, your local hardware store, where ever and purchase spools of the correct color wire.

Once you got all that stuff just make your own wires. Notice the wiring diagram jayharrell posted. It tells you exactly what color and gauge of wire you need. If you didn't know, 14Y = 14 gauge yellow. 14DBL = 14 gauge dark blue, etc.

I hope this helps.

Re: Factory A/C & Heater Help
 

Thanks for the diagram, and I also appreciate the part numbers. I'm gonna give that a go for the next step. I'll keep posted...

Re: Factory A/C & Heater Help
 

Got pretty much everything all fixed up, replaced all the bad wiring, made new solid grounds for everything, replaced all the vacuum lines, etc. Now I'm having an issue with the factory wiring diagram. On the diagram, the clutch green wire, and 14ga yellow wire from the control switch go to a 'compressor switch' (circled in picture).

http://img296.imageshack.us/img296/4...ramcopyef9.jpg

The problem is, I don't have anything on the back of the A/C controls that these wires can connect to. Where is this 'compressor switch' supposed to be mounted? Does anyone have a picture? Also, my harness does not have the anti-dieseling wiring, that shouldn't have anything to do with the 'compressor switch' wiring anyway, right? Thanks,

Re: Factory A/C & Heater Help
 

Thats the difference between the diagrami posted and the one you have. The anti dieseling deal is more of a saftey add on deal. Supose to keep the clutch on the compressor locked for about 5 seconds after the key is turned off to keep the moter from jumping up after the key is off due to the new HP from the compressor being uncluchted. If that makes sense. mine didn't have it, so i went with the non dieseling diaghram.

But i'll get a picture of the compressor switch. its on the back of the dirvertor. There is supose to be a switch that attaches to the back of the divertor box, its actuated by a cam on the divertor itself. When you move the controlls to AC, it pushes that switch.

Re: Factory A/C & Heater Help
 

Yeah, I'm pretty sure that I don't have that switch on the divertor box. If you could post a picture, that would really help out.

Thanks,

Re: Factory A/C & Heater Help
 

Most cars and trucks have the blower motor hose that is cracked on yours.Just go to a junkyard and find one that is close enough to fit if you cant order one.

Re: Factory A/C & Heater Help
 

Thanks for the tip, I'll check into a couple yards around here.

Re: Factory A/C & Heater Help
 

i couldn't get a picture of my box last night, but found this pic. The bracket on top there should have a switch on it. Hope that helps