a/c not working in 96 explorer

[greger]

alright i got a 1996 ford explorer limited and the a/c decided not to fire up this year i checked the pressureat the anticipator and its reading about 125psi wich is way to high. and my compressor is not turning on.i checked the power at the pressure switch andfound nothingi even jumped the connectiong fromthe pressure switch to thecompresser to seeif it would turn on and nothing so then i checkedmy fuses and they areall goodso doesany one have any ideas?? imthinking maybe a pinchedwire or something cause i did just get a bunch of work done to mysuspension so could thgat be a possibility? plkease any help will negood cause lasttimeitookthe truck in to get the a/c checkedi walked out with a $3000 bill.so any help on thingsto checkwill be appreciated.


thank you.

 

[96eb96]

alright i got a 1996 ford explorer limited and the a/c decided not to fire up this year i checked the pressureat the anticipator and its reading about 125psi wich is way to high. and my compressor is not turning on.i checked the power at the pressure switch andfound nothingi even jumped the connectiong fromthe pressure switch to thecompresser to seeif it would turn on and nothing so then i checkedmy fuses and they areall goodso doesany one have any ideas?? imthinking maybe a pinchedwire or something cause i did just get a bunch of work done to mysuspension so could thgat be a possibility? plkease any help will negood cause lasttimeitookthe truck in to get the a/c checkedi walked out with a $3000 bill.so any help on thingsto checkwill be appreciated.


thank you.

Are you saying the static pressure at the accumulator/drier is 125psi when the truck is off? Should be about 75-80. Are you jumping the switch on the accumulator (passenger side)?

Check for voltage at the clutch connector (on the compressor) when you jump the switch. Maybe the compressor clutch is bad?

 

[charsawbis]

I have the same problem...no AC.
I havent checked the pressure like you have but my compressor clutch seems to be the issue. It cycles on and off but wont engage.
Does you clutch cycle at all on the compressor? Set it to max AC and see if it tries to run the compressor. That might be the problem.
The pressure will build up too if the clutch doesn't run properly.

Good Luck

 

[greger]

yea i have checked the voltage at accumilator andi get no voltage at allandi get 125psi when the truck is running..so its not getting any voltage at all. so mycompressor isent doin anything becuase its not getting any power or a signal to do anything thats why i thought fuse but my #18 in side the driver door is fine and thats the only one that the book says is connected to the a/c that is then why i was thinking broken wire???

 

[Dilbert5]

You have verified that there is no 12 volts at the clutch,, so I checked the schematic, and 12 is supplied from the climate comtrol, passes thru the pressure cycling switch, then thru the WAC switch (high pressure cutout). It then passes thru the WOT AC RELAY, from there it goes to the compressor clutch. I would probably start at the relay and see where the12v is lost.

 

[greger]

ok well i do have high pressure so that wac is looking good where would i find these parts? and the samewith the wot ac relay. any idea where they are located? and how can i get the pressure down on the accumilator?

 

[Dilbert5]

I don't believe that you need to worry about the pressure right now, it is not high enough to trip the overpressure switch, so it will not keep the compressor from engaging (off the top of my head, the high pressure cutoff is close to 300psi). The relay is easy to get to, it is located under the hood and is clearly marked. You will need to determine if there is 12v to the switched side, and if the coil is enabled. Depending on what you find here will tell you which direction to go from here.

 

[greger]

Alright so this relay is just in the fuse box under the hood cause there is a blower motor relay is that it? And just switch it with another relay to test it?

 

[Dilbert5]

it's on the left hand side of the engine compartment, on the inside fender well. It is labled WOT AC relay. it is located right next to the PCM power relay. As a quick check you can swap it with a identical relay. But if that doesn't work you will need to use a DVM to check voltages.

Of course, shut the car off before swapping relays

 

[marragtop]

You can swap it with the fuel pump relay, but then the engine won't run. Shouldn't matter, you just need to find out why you don't have 12v at the low pressure switch. Don't forget to check the associated fuse(s) as well.

 

[greger]

oh ok so its sjut in the under the hood fuse box then? so i will try to check that tomorrow thanks for the help i will keep you posted guys

 

[greger]

do I just swapped the relay with the fuel pump one and I still get nothing happening no power at the pressure switch connection and with jumping that even I don't get the clutch ingaging what to do now?

 

[Dilbert5]

In post #2, there is a link fo download manuals, I would download the appropriate one. You will need the schematics in there to trace where the signal is bing lost.

 

[greger]

Hmm alright well I'm actually doin all this off my phone so it will be a while untill I can get that file downloaded

 

[Dilbert5]

Unfortunatly they don't allow the uploads here, or I could upload a copy for you.

 

[greger]

those are jsut the manuels arent they which i have to factory one and the haynes one..and they werent much help.

 

[marragtop]

Have you tried running a jumper from the positive side of the battery to the compressor to see if it engages? This will bypass the relays, the low pressure switch and the dash switch.

 

[greger]

not soi guesseiwill try that nextbut i figurewith jumping /checking for power at the connectiongat the pressure switch thatits prittymuch the samething

 

[moga]

I also am without A/C. I don't know what the pressure is but I was told that the system has too much pressure to add any coolant.

After reading this thread, I got my voltmeter out and checked the power at the A/C compressor and got zero.

Q:

1) Because the dongle for the electrical connector to the compressor is so short, I did not check the voltage while running the engine. Instead, I read the voltage while the ignition switch was in the position that's just before the starter is engaged. Should this position give me a reading while the A/C setting is engaged?

2) If the ANS to Q1 is yes, should I then back trace the system according to the instructions in post #5?

EDIT: The compressor wheel does not move when the car is running and the temp selector is set to A/C or MAX A/C.

 

[Dilbert5]

I also am without A/C. I don't know what the pressure is but I was told that the system has too much pressure to add any coolant.

After reading this thread, I got my voltmeter out and checked the power at the A/C compressor and got zero.

Q:

1) Because the dongle for the electrical connector to the compressor is so short, I did not check the voltage while running the engine. Instead, I read the voltage while the ignition switch was in the position that's just before the starter is engaged. Should this position give me a reading while the A/C setting is engaged?

Being cautious around moving parts, very good, but unfortunatly the ECU does not allow the engine to engage the compressor until after the engine has been running a few seconds. You can measure the resistance of the clutch to dtermine if it is open.

2) If the ANS to Q1 is yes, should I then back trace the system according to the instructions in post #5?

EDIT: The compressor wheel does not move when the car is running and the temp selector is set to A/C or MAX A/C.