Need Help! AC Compressor is ALWAYS on when the X is running!!

[unpredictable1]

Need Help! AC Compressor is ALWAYS on/UPDATE: FIXED!!!!

Update: I fixed it last night and heres what i did. Ripped the whole dash bezell out, the piece all around the stereo, your light button and everything. Hauled the stereo out, hauled the heater controls unit out.

Plugged in the AC compressor, started the truck. AC never started automatically. got inside and turned on AC, compressor started. turned it off...it stopped. wtf??

Then I found something on the heater controls, that is located inside the dash when everything is put together. A small little lever. With the AC off i pushed the lever down, the AC came on. It must be some sort of manual override for testing.

Turns out from what I could see, the extra cables and wires from my stereo must have pushed this lever down (the AC didnt work when I bought the truck, I had a stereo installed right after purchase, so i never would have noticed this problem). I re-routed the cables and put it all back together and it works great. NOTE: I placed a nice strip of weather strippingunder the lever so it can't be pressed down so easily.

Thanks god this was an easy fix!!!!


And thanks to all those who replied!
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A while ago for those who can remember, I had my AC replaced and it got upgraded to the new refridgerant.

I recently had a problem and some board members steered me in the right direction that it was the compressor that had seized....even though it was freshly rebuilt...anything can happen.

it got replaced today, and they found out something..

somewhere i have an electrical problem because my Compressor is on all the time. whether you push the AC knob in the truck or not. whether you just want to use the regular panel heat....AC is on and the compressor is running.

They did a very basic troubleshooting test and theres current going through the relay ALL the time. its always open.

where can i even begin to look to find this problem??? the actual switch mechanism/heater controls themselves??

Thanks!!

Leo

 

[MyExpWork]

Well, you gotta trace it short (or whatever) from the switch all the way to the relay and then to the compressor itself. Just curious, but since it sound like this is your second compressor from this place already I would test the compressor. Just unhook the connector from the compressor. If the clutch disengages, then once again its the compressor. Then apply 12v directly from battery to see if it re engages.

Basically take a 12v meter and run it along all of the relays, switches, etc from the A/C switch on the dash out to the compressor. If you get 12v when your not supposed to have 12v that is your problem area.

I would start at the A/C switch. Dissconect and see if that is closed circuit all the time. With the switch turned off it should be an open circuit (no volts), when you press switch on, you get a closed circuit (12v).

Good luck. Hoped this help some.

Brian

 

[unpredictable1]

thanks for the reply. but heres some more info...

when i brought the truck back i had said maybe the compressor was why my AC was always on, they said it was possible and went ahead and replaced the faulty compressor.

they put it in and realized that the thing was always engaged. they tested the relay and theres always power going through it. so somewhere before the relay something is telling my air conditioning to stay on.

i was thinking that since there is a signal going there to turn the ac on, or heat or anything, it just can never turn the ac off unless you shut the heating system off all together...it would be the switch...i'm shooting in the dark.

i haven't picked up my truck yet, and well i want to check it out myself before i end up paying through the nose for labour getting it looked at.

that compressor can't be at fault because it hasn't even left their premises yet and they are trust worthy, i know it wouldn't be the compressor at this point...

thanks for the reply!!!

keep em coming

leo

 

[MyExpWork]

I would start at the switch. Find the wires that lead to the switch, put a volt meter on them, I imagine it will be something like one wire going in and one comming out.

Test both-if both have 12v the switch is probably bad. But just to make sure I would then remove the wires from the switch, then if one goes cold and the other is still hot, its the switch. Then, be carful not to blow a fuse, but touch the bare wires together to see if the compressor engages then disengages after you seperate them. If everything goes as I wrote it =bad switch. If not, you'll need to follow the circuit to where the 12v is "entering" and turning on the compressor.

Its like anything else, finding a short is easy, if you know what you're doing.

Good luck.

Brian

 

[unpredictable1]

so basically, i could just run a new wire and re-attach the existing plug that goes into the compressor with a new one can't i? can't be that hard.

i'll try what you said, when you say put a volt meter on the wires, how do i get a conncetion? shave off some of the wire insulation/coating? or jump the connections right at the connector...

i'll have to rip it out to see what i'm messing with.

i hope it comes out easy enough, looks like it comes out from under the dash.

thanks again!

leo

 

[MyExpWork]

I have a volt meter but if you have one of those pen looking things that has a sharp point, a light on the end and an aligator clip (for grounding) you can typically push the sharp end through the outer covering of the wire. Put the aligator clip on a good ground (maybe test the ground first) and push the other end through the wire skin. If the light goes on you have voltage. The cool thing is that light acts like a volt meter in that as it gets more power from the wire, it will shine brighter.

Otherwise you'll have to put your voltmeter in the plug. Push it in the "hot" side, then try the "cold" side.

There may be more than two wires going into the switch, I am just giving examples, get a repair manual and find the a/c switch in the wiring diagram, it will tell you how everything works.

I am not an expert at this stuff but this is what I would do.

As far as running a new wire, I would use that as a last resort. Try fixing the problem by finding the short. I don't think you have a bad wire, but only a bad switch or relay.

Anyone else have any suggestions?

Good luck.

Keep us posted.

Brian

 

[OL Crony]

i'm not as technically savvy as the rest of you guys, but on my 92, the compressor runs all of the time unless it's in the panel position. it's real annoying. i also, a couple of years ago, replaced my compressor and added the new refridgerant. the garage showed me the cost differential and swayed me in the direction of the new refridgerant. i don't think it's as cold as before and the new compressor is louder. the new stuff seems to only work if the truck is driving. i think that those few things are the only changes. tell me i'm crazy.

az

p.s. - after i got mine changed out, someone on this site replied to one of my posts about this exact thing and he said that the early fords were programmed to do that exact thing - just keep cycling. i have learned to live with it, although, admittedly, i wish i had gone the other way and went with the old stuff (r-12?). then again, maybe the new r-12 compressor would have been just as loud - who knows. we need an ac tech to answer here.

 

[unpredictable1]

well see, cycling or not, it will always blow cold air via the AC compressor instead of just taking vented air to do the same.

for example, i get in my truck and put the temp selector on cold and then place the selector for air position to panel or anything and it will blow icy cold air, even with the AC off. see what i mean?

BRIAN: thanks for your replies, i'm going to test the controls themselves because, for what i think, if there was a short somewhere, it wouldn't come on/blow cold air at all.....

thanks to all those who looked and replied...

leo

 

[unpredictable1]

ttt