A/C compressor?

[b_train_98]

I'm not having much luck finding info for this. My compressor doesn't want to kick in. I pulled a few fuse's and tested the relay with a jumper wire, it's all good. I'm %75 sure I'm getting power to it. I don't know what the pressure was before I charged, now it's at the top end of a full charge. I used a dummy gauge for DuraCool, it doesn't have psi just color coded. I don't remember the last time I heard it kick in, even in the winter (it de-humidifies right?). Not sure what the next step should be. I'm melting already and it's not even summer yet! Any idea's? Thanks for your help.

 

[seth247]

all you've got to do is push in the fan knob, pull the connector off of the compressor and check it with a voltmeter. if it shows voltage then i would say youve got a problem with the clutch. if not then id say you're low pressure switch is jacked maybe. i think there is a forum just for the explorer a/c system and the people hangin out in there would know more than me.

and yes when you push the selector switch into "defrost" the compressor should kick on

 

[b_train_98]

not good

I tested the wire before starting the truck, nothing(a starting point). Started her up a/c on max a/c and tested the wire. I got nothing. Also I forgot to mention, I can turn the clutch by hand with resistance and it springs back out. I don't know much about clutch's, I think it's normal. As for posting to the a/c forum, well that just makes sence. If my hat rack was working properly I would have looked closer and notice there is such a forum on here. Holy crap I need sleep. I gues I have some copying and pasting to do, thanks for the help.

 

[glfredrick]

You are probably low on freon. It takes a minimum charge to actuate the pressure switch in order to kick on the compressor. Dump a can in and see what it does.

 

[b_train_98]

overcharge?

I did put a can in before I did anything else. The gauge said it's at the top of a full charge, meaning very close to a overcharge. What exactly happens when it's overcharged, I know it's not good? I will double check tonight or tomorrow, I have a 2 hour drive to do yet. Maybe I'll check it when I'm waiting on the rad to drain to replace it. I'll let you know what I find, thanks.

 

[slowhand9495]

Switch Maybe

If your not getting any any power at the wire when you push the fan switch in,Its possibly the switch. We've sold several of those already this spring for this model Explorer. I would take a test light, disconnect the wiring from the switch,turn the ignition on and make sure you do have a hot wire at the switch. If you have power at the switch, I'd replace it. Also, the pigtail at the compressor field coil is notorious for giving problem. Check it really good.
Good Luck

 

[b_train_98]

psi?

I should be getting power to the fan switch, the light does come on. I assume it's the same wire that provides power for the light. I kinda lied a little to. My Duracool gauge does have a psi number (oops). Right now the low side is sitting at 30psi, as I understand it should be between 25 and 38? This compressor just doesn't want to kick in for some reason. Could there be to much of a gap between the clutch and compressor? I did read something about that, not sure where though. My rad job wasn't all that bad, found a chunk of cardboard in between the rads. Must have been from previous owner, it explains allot!

 

[safn1949]

OK,find the low pressure switch and jump it with the A/C on,engine running,if the wiring is good and you have power the clutch will engage even with no freon.Just pull the plug from the low pressure switch and jump the connector,that will at least give you a starting point.

 

[b_train_98]

jumping=nothing

I jumped the switch today. It was a little awkward to get the wire in the plug so I played for a few minutes, couldn't get the compressor to respond at all. Correct me if I'm wrong, there is diode in the wire somewhere, maybe that went south? What do you suggest next, if you haven't noticed I'm not to familiar with a/c systems.

 

[safn1949]

If you had the right switch and jumped it correctly then you have a power problem somewhere,I would also take a test light and see if you have any power at the switch with the A/C on and the blower switch on.I don't have my book to look at the wiring diagram as I drive truck over the road and am out on the road right now,so I can't help you much more now.Although I have a 94 explorer,I did all my work on GM vehicles so I can't tell you of the top of my head.

 

[b_train_98]

Technically I never did OTR, I have been on the road for weeks at a time though. I used my multi-meter on the switch and wire. It's a tight fit to probe it so I'm not %100 positive I had a good connection (I did take my time). I think I have a test light in my truck so I will see if I have power to the compressor then the switch. When the wire is disconnected from the switch, I don't see how the switch would get power so no point in jumping that? I'll see if I can find a wiring diagram, don't see one in my Haynes.

 

[safn1949]

No,just see if you have power to one side of the switch harness,if not then you need to find a diagram of the power circuit. Haynes and others like it are ok but if you can go to a dealer and ask to see a factory service manual,they might still have one.

 

[b_train_98]

perplexing

Lets add to the confusion. Thanks to another post, I used a paper clip to help with this. I now know (beyond a doubt) I have power to the switch, just under 12v (my truck wasn't running, key on and a/c was on max). I do have power to the compressor, no where near 12v though (how much should it have?). Then I jumped the wire harness for the switch (I'm starting to like paper clips) and the compressor did not come on at all. What should the pressure's be? I thought around 35psi for the low, could be wrong. Also the psi is down again (25). I have a can of sealant that I haven't used yet. Is it possible to charge the system when the compressor doesn't kick in? That's not the plan yet, just wondering. Thanks again.

 

[safn1949]

The truck needs to be running then jump the switch and the compressor should kick in no matter what the pressure.Get that to happen first,then go and have some dye put in and recharge the system and look for a leak. The dye will show up real easy,I guess you could do that yourself and refill also,but in the end,if and when you find a leak you will need to repair it and then do a vacuum drawdown and let it sit for an hour or so to remove all of the moisture and then recharge. All of the air and moisture must be removed,it forms acids in the system and lessens the cooling output.

 

[b_train_98]

Pita

What a pain in the ** this is becoming. Just to be sure I did it again. I used a paper clip and jumped the switch, this time with the truck running. No luck. This is what I'm thinking; remove the belt and make sure I can turn the compressor by hand; I'll jump the compressor directly from the battery and see if it starts and look for and hopefully find a diode that sounds like IS in this system? If I have to take it to a shop and I really don't want to, I'll get it vacuumed and hopefully do the rest myself. I know a/c is not the thing to go cheap with and I would like to save a major expense, I don't trust shops around here, I've been burned a few times already (brakes I didn't need). Hopefully have time tomorrow to play.

 

[seth247]

you don't have to pull the belt. When the ac clutch engages it will make a loud click. As in hear it inside the car loud. If you haven't heard this click the clutch is not engaging. Or it is stuck. The compressor won't turn with the engine off but it will click.

 

[safn1949]

Yep,he's right,I just happen to be deaf as a plank,so I can't hear it most times.If the clutch is bad,now you are talking more money then you want to spend,I would guess.The easy way to fix that is a rebuilt compressor and then all the stuff I told you before,as I said big bucks.The clutch is nothing more than a magnetic switch so if you have power to it and can turn it by hand,it's hosed.You must make sure there is power to the clutch before you decide it's bad.Go ahead and jump it from the battery,you will hear it click and then try to turn it.However if you are losing pressure you might have more then 1 problem although the clutch seal could be leaking,or a compressor fitting,in that case a new compressor would fix that.It's a pain and expensive,I know I used to do that for a living.Good luck.

 

[b_train_98]

Ok. I couldn't figure out which connector is the power and which is ground. I had my test light on the positive battery looking for ground on the compressor. It didn't light up. The compressor it self is grounded though. And yes I tested my test light it does work. The only power I can get to the wire harness for the compressor is less than 1 volt. I don't think that would be enough to get it going? I had just under 12 volts at the switch. Losing power between the switch and compressor. I assume the connector under the accumulator is going to the fuse box to get the power in the first place (from the relay). I would have to rip things apart to be %100 sure. I like troubleshooting like this, even though it's getting frustrating.

 

[safn1949]

OK,I would now get a wiring diagram to save yourself a lot of time and headaches,take your time and make sure you understand the diagram and then start testing.

 

[b_train_98]

Would I fry something or cause more damage if I jumped the compressor and didn't know which connector is ground or positive? Didn't have time to goto ford dealer and get a wiring diagram yet, I will tomorrow so I can play on the weekend.