A/C Help! (Getting hot)

[Synned]

Okay, well I haven't had a/c since last summer, and since summer is rolling again I kind of need to get this fixed. I thought it was freon, but I put a can in and it didn't get any colder. A few weeks later I bought a can with a gauge on it, hooked it up and it read 100psi. Oops. So the car blows warm air, I don't even know what the next step is to take because I know there is a leak in the line.
What should I do next? I don't really have money to take it to a shop...but will if needed.

Thanks guys
Joe

 

[94gts]

you have a vert why need a/c?

 

[sage2k]

passenger side by firewall there is a black thing attached to firewall with an electrical connector on top of it, mine was cut and i fixed it, took 1 minute literally lol, and now its cold again

 

[Synned]

Yeah, the vert helps but 85* on your head in humidity gets old after a while. I love the vert on summer nights though.

Anyway, I looked at the passenger side firewall and saw two connecters, one that was like roundish and it was a wire that ran along the top, plugged into another, looked fine and the other I think was the FPR. The computer plug was also there.

Everything looked okay.
ANy other suggestions?

 

[HISSIN50]

You really need to hook up a manifold gauge and note the low and high side pressures, noting ambient temps.

A shop would probably do this for you for very cheap. If you were close, I'd loan you my manifold gauges.

Good luck.

 

[SeventyMach1]

100 psi seems a bit high. Were you adding to the low pressure side or high pressure side? I believe you're supposed to use the low pressure side.

I think they have different fittings on each side to prevent this .... but I'm not totally sure.

 

[HISSIN50]

Justin is right on, as usual. 100 is out of sight for the low pressure side. And one should not be able to hook one of those can taps into the high pressure side.

We should ask - does the clutch engage? The switch Sage mentioned is the low pressure switch. If the A/C clutch is engaging, the LPS is working (the switch kills the juice to engage the clutch if the system is low).

Good luck.

 

[mo_dingo]

The first thing I would do is evacuate the system and recharge it to the right pressure (30-40psi is right I think, should say on the gauge). Then see if the low pressure sensor is passing current through to the clutch. If it isn't, r/r the pressure switch. If it is then check for 12V at the compressor. If you have it, your magnetic clutch is bad. If you don't, you have a 12V wiring problem and need to trace it.
Scott

 

[Synned]

The side I have been filling and see 100psi is the driver side. I'm positive it is the low pressure side. How would I get the extra pressure out, because I think the clutch won't engage if there is too much pressure as well.

EDIT:
Okay, I relieved the system of the excess pressure, probably not the right way but I did it.
Still no cold air, and I'm pretty sure the compresser is not kicking on.

 

[94_Teal_GT]

IIRC, if the compressor isn't switching on, then you will get about 100 psi reading on the low side. I remember seeing my readings about that high when my compressor wasn't working.

There are two switches that can stop the compressor from engaging. One was mentioned further up(low pressure black 'canister' near firewall). The other one is between the airbox and the radiator(high pressure switch). If either of those switches is bad or corroded your compressor won't start.

For me the front switch was corroded and wiring had lost all the insulation near the switch. If the wiring looks good, unplug that high pressure switch and look inside if it's corroded clean it out. I repaired the wiring and I had to slightly bend the prongs apart to get a good contact from the plug. Mine has been working for several months. Click here for some more info

You will probably have to re-recharge the system if you bled it down and the compressor wasn't running.

 

[Synned]

I'm going to go try to jump the high pressure switch, the one near the radiator. How would I try to jump the switch near the firewall?

EDIT

Okay, I just jumped both switches, the one on the freon line i jumped blue yellow to green orange, and the other switch I jumped the two together.
Neither helped anything.
Am I supposed to jump them on the female side or the prong side?

I also checked the fuse, its fine.

 

[94_Teal_GT]

I'm going to go try to jump the high pressure switch, the one near the radiator. How would I try to jump the switch near the firewall?

The low pressure switch only has 2 wires on it purple and blue/yellow. Just connect those 2 together.

If your system pressure is really low, do not run the compressor long or it will burn up! By all means if a switch is bad, replace it, don't use a jumper wire just to get the system running again.

EDIT:Jump the wires(female) not the switch(male). BTW, when you jump the high pressure switch it takes about 5-10 seconds from the time you jump the wires until the compressor kicks on.

 

[HISSIN50]

If you didnt have enough pressure to kick on the A/C clutch compressor (it isnt kicking on, right?) then relieving pressure probably isnt the answer. As was said, numbers need to be evaluated with the compressor engaged and engaged for a relatively decent duty cycle.


Good luck.

 

[Synned]

If you didnt have enough pressure to kick on the A/C clutch compressor (it isnt kicking on, right?) then relieving pressure probably isnt the answer. As was said, numbers need to be evaluated with the compressor engaged and engaged for a relatively decent duty cycle.


Good luck.

Even with the pressure re-filled, jumping both switches yielded nothing. The pressure is re-filled back to 100psi with no compressor (Around what it should be w/o it).
So, with freon in there, and both switches jumped, why else wouldn't it kick on?
The fuse is also good. #6 in the dash.

 

[HISSIN50]

Because checking pressure with the clutch disengaged is pretty useless, the trick that everyone is getting at is:

If the clutch wont kick on (engage), it's very difficult to introduce fresh R134 gas (not liquid) into the system. So just to charge it back up enough to get the A/C clutch to kick-on by itself, you would have to jump the Low pressure switch terminals. Assuming the rest of the wiring is sound, this kicks the compressor on, and you can now introduce your fresh R134 into the system. Dont run the system very long with the LPS bypassed/jumped. Keep an eye on your pressures so you can know when to stop filling and unjump the LPS jumper. Now the clutch should engage on its own.

DO be real careful with refrigerant - it can freeze fingers, eyeballs, etc.

To others - I dont mean to step on toes (I REALLY hate it when others repeat what I have already posted). I rehashed some of what was already said, but it wasnt because your posts were already noticed and noted.

Now if you know pressure is good, the clutch itself could have crapped out. It has a tight tolerance (it's electomagnetically activated).
To chase the electrical side further, I would look for a drop in the 12 volt signal on its way to the clutch. Start at the A/C clutch. See if it's getting 12 volts with the A/C on. For fun, make sure it has ground too. Working backwards, I would have to check a schematic but I bet the pathway is through a WOT relay (in the CCRM IIRC). Then it goes back to the LPS. Make sure the LPS has 12 volts in and out.

Good luck bud.

 

[Synned]

Okay, so today
I jumped the low pressure switch, there is 12 volts there when a/c is on. Compressor doesn't kick on, however the fan does.
There is NOT 12 volts at the compressor. I found the plug, no voltage there. I also tried to jump the high pressure switch. Didn't check the voltage there.
I guess I have a damn wiring problem. Where do I start?

Thanks for all the help guys
Joe

 

[Synned]

ttt!!

 

[HISSIN50]

IF you have juice at the LPS but not at the clutch, I would look at the WOT relay (in the CCRM).

 

[Synned]

Does anyone know where the accumulator switch is?

I found someone with almost the exact same problem..

I have a 1994 Mustang and the air conditioning works intermittently. The low-side pressure reads 80PSI. I put some LEDs around the AC electrical and noticed that initially the line out of the AC high pressure cutoff switch is normal (12V) (this feeds into the CCRM). When the CCRM decides to assert the compressor clutch, the AC clutch pressure switch cuts out (goes to 0 volts) and the CCRM disengages the compressor clutch. I do not see a change in pressure on the low side (constant 80 PSI). Also, I never see the clutch engage (compressor never turning).
I have noticed that sometimes, I do get AC.

This seemed to help him out
Try jumping the cycling switch on the accumulator

BTW Sorry for posting this in two places guys, just two different groups of people!

EDIT:
Well the accumulator switch is just the switch by the firewall...right? So I already tried to jump that.

Any help would be appreciated guys .
Thanks

 

[smokediver27]

Not sure if this will help you or not, but I just got mine back from AC work today. I did the same thing, tried jumping both switches without luck, checked for voltage at the compressor, ect ect ect. When I hooked up the charge unit, I knew it was low, but I could not get it to fill since the compressor wouldnt kick on . 138 bucks later, my AC works again. It was low on freon, and while they were at it, I had them replace all the o rings and such to eliminate a few small leaks I had. Air blows ice cold now.