In my 92 w250 it appears to me that the previous owner must have wired the A/C compressor to a toggle switch under the dash. I am not sure but from reading a few previous posts it seems like maybe it has something to do with everyone wanting to eliminate the ecm circuit controlling the clutch engaging on the compressor. Any how I tried it to see what it does and the a/c works clutch engages and the air starts to get cold "BUT" it looks like smoke starts to rise up out of my steering column while I have the compressor clutch engaged. I turned it off and let it sit and fired it back up and after running it with and without the compressor engaged it seems to only do it when the compressor is turned on. Anyone heard of this or think you could maybe lend me a bit of advice? If i can id like to follow one of ya'lls designs and fix it to where the compressor will cycle on and off itself. Thanks guys

 

If possible you need to find where they took the power supply from for the sw and is it fused? They may have tapped into something else with smaller wire and it could be frying those wires.

Just a thought but..... are you sure it's smoke? I have seen systems that are running so cold that ice crystals would come out the vents. This is easily mistaken for smoke.

 

Ice from the vents, that sounds realy good to me since I'm in houston and mine doesnt work. lol

Check to see where the 12v is coming from, and where he grounded it. It shouldnt pull to many amps so even 16 gauge should be fine.

 

I guess I should clarify that statement, Ice crystals from the vents in humid weather when the system is not running properly and is on the verge of freezing up, which could be the case with yours if it is being controlled ONLY with the sw.

 

I wish ice coming out of the vents was all i have to worry about. I tried to take some pics but they didnt come out good after i resized them. I belive I found the source of my problem. The smoke I was getting was coming out of my steering column. It appears this guy just wired in to the first 12v acc wire he could find. It was causing the smoke because he spliced into the big black wire with an orange stripe coming from the ignition to where it enters right behind the fuse panel. I havent found the diagram or taken time to look and see what circuit/function that black&orange wire ties to because I have to go to work but apparantly it cant handle the load of the compressor while doing its own job. Not to mention he just peeled back some of the insulation and wrapped the other wire around it and duck taped it. SHeeSH Man that sucker was getting HOT i thought that wire was going to spontaneously combust. Any suggestions of where I can run the new wire Straight to the battery with an inline fuse or anyone have a diagram to where i can return it to its factory switch? Anyone see a reason why he would do this other than bein lazy or cheap and not wanting to buy a cylcling switch??

 

go to autozone and get an $7.99 fuse block and an $5 lawnmower battery cable (I used 19" shortest one I could find) and then you have a new fuseblock.I redid my fuseable links and some other junk through them. I got 2 new block (12 fuses) and just got a short peice of amp wire and made a short jumper to the 2nd. Only thing is that they are always hot so what ever you run to them you have to turn off.

 

Ghostrider - the logic behind this is the fact that we have now way to close off outside air when the heater is on...By wiring the switch, you can turn on 'MAX AIR' and turn up your heater and your fan - but not engage the a/c...Now you're recirculating the heated air in the truck instead of outside air...Truck heats up faster, and better when you get REALLY COLD outside...

My LeBaron Conv had a switch in the controls that did the same thing. Even tho the conv top let in some outside air, I was nice and toasty inside on max air ( recirculate ) and the temp about 3/4 to max...

 

Does anyone know if those 91' wiring diagrams in the stickys would apply to my 92 a/c system? If not anyone know of a good diagram

 

You might check with loch, he fixed my a/c today for me. He had a couple of them, might be one that you need. Good luck, my a/c was down for a month and of course the hundred mark was hit during that time....

 

Ok I'll take any help I can get id really like to return in back to the factory wiring so the cycle switch and low pressure switch control the compressor and keep it from burnin up. I still have R-12 in the system and have a buddy that has some of that liquid gold layin around so i wanna keep it that way.

 

No, the '92 and up A/C systems involve the PCM. The only difference is that all the switches that would just turn on the compressor in the old setup tell the PCM that you want A/C, and the PCM turns on the A/C relay.

Is the truck charging?

 

Anyone know where I can track down a diagram I can follow or a good place to look for one. It really didnt suprise me when I looked through the chiltons and it had engine wiring for 92 w/ diesel but no chassis section for my truck. Any tips are greatly appreciated. Thanks for the headsup Wannadiesel Ive been studying the wiring diagrams for the A/C for a 91 from the stickys so i reckon its time to toss em and start over. LOL Do you know if the color coding is the same as on a 91 as far as the wires coming from the switches? I havent gotten deep into looking at it but im assuming thats where the toggle switch would be going to.

 

i reckon ill see if i can get one from the local dealer