1995 Olds 98 - A/C Will Not Come On FIXED

[autoxperts]

1995 OLDS NIETY-EIGHTY REGENCY ELITE. CAME IN WITH A/C CLUTCH OUT. CHANGED COMP. DRYER ORFICE. PULLED VACCUM STARTED CHARGING COMP. WOULD NOT COME ON. CHECK FUSES,RELAY ALL GOOD TRACED WIRES.

EVERYTHING HAS POWER EXCEPT GREEN WIRE GOING TO COMP.

[liljoe]

Will it come on if you jump the relay?

[autoxperts]

YES

[liljoe]

Is the PCM commanding the compressor to come on according to your scanner?

[autoxperts]

NO

[autoxperts]

SORRY YES

[steven kiser]

i remember that on some gm's they would store a code and if it wasn't cleared the climate control wouldn't work.

[liljoe]

At the relay, check both pink wires and make sure they have battery voltage on them, then ground the dark green/ white wire and the relay should close and engage the clutch, if so check the dk grn/wht wire back to the PCM, if wire is good then PCM is bad.

[autoxperts]

pcm did not fix problem.

[ricmorin]

Is this a manual or automatic climate control? If it's automatic, you'll need a scanner that can access the module.

[steven kiser]

like ric said, you'll need a scanner to access the module. the air temp sensor in the car may be bad keeping the compressor off. i'm still not seeing anywhere that you read for codes in the climate control system. if there are codes system will not activate.

[autoxperts]

it is automatic. do you have to have a tech 1 scanner

[ricmorin]

I have a Tech2. New and improved. You need to talk to the HVAC module and see whats going on there.

[autoxperts]

all i have is a solus pro

[ricmorin]

Have you tried accessing the module? Snap-On makes some pretty good stuff and will often get access. If not, you'll need to find someone who has one or has access to a Modis.

[autoxperts]

it will not access .thanks

[sbebenelli]

Have you tried accessing the module? Snap-On makes some pretty good stuff and will often get access. If not, you'll need to find someone who has one or has access to a Modis.

Solus Pro & Modis have the same scanner functionality so if the Solus doesn't do it neither would the Modis.

[steven kiser]

ok, you've replaced the pcm and chased all the wires. all the pressure sensors are working. the power wire to the compressor isn't powering up until the relay is jumped. is the relay getting a signal to trigger? it may be a ground signal as well as a power. haven't looked into the schematic. if there is no signal and you can't read the system the the issue may be in the control head. on occasion i see collateral damage in these systems. the issue may have been the control head (module) shorted and caused the compressor to overheat. i don't think these are programmable so a used one from a salvage yard should be ok. if i'm questioning a burnt module a quick sniff can end any question. if the board is bad it will still carry that burned smell. it lessens but never leaves. another quick tell is if you use a magnifying glass to look at the plug on the module an over heated circuit will usually discolor a lead. it may be grey instead of silver. the shade change is noticeable. the other control sensor is the cabin temp sensor. if this is shorted it may disable the module as well. good luck.

[autoxperts]

it does have power to the relay. if you jump the sensors will not work.

[steven kiser]

ok, so i'm hearing that when you turn on the a/c in the car the compressor relay powers up.

it does have power to the relay. if you jump the sensors will not work.

in previous posts i read that the sensors all are working correctly. the only wire that won't power up is the compressor clutch wire. you stated that it would trigger if you jumped the relay. now i'm reading that the relay is powering up but the compressor still wont trigger. i know that i miss things being posted and although i can carry on a great group or one on one conversation my communication skills on the forum wane at times but, if you jump the relay and it works and when you turn on the a/c the relay powers up then the relay is junk. the other question i have is when you're jumping the relay are you powering it up from an outside source or jumping pin to pin. if you're using an outside source have you checked the amp load at the relay? i've seen 12 volts with very little amps because of a bad connection. the relay may in fact have a secondary trigger. a starter relay will only trigger when it's triggered by the safety switch and the ignition switch at the same time. the in line sensors work on two levels. one side is pressure control both positive and negative (high or low) others are temperature controlled. on some systems if the pcm is reading high engine temp it will kill the compressor. the quick test is if the cooling fan is on high as soon as you start the car look at that circuit. i wish we were sitting at a table discussing this. it would be so much easier bouncing ideas back and forth.