&*&^%$$#!! CEL takes out AC????

Drat. I've got an intermittaent boost problem I can deal with and am working on but I tried to use my AC (taking a few guys to lunch....NO GO I'm thinking its because of the cel......Does that sound correct? The reason I'm agitated is I'm soon to be going to NC and back with my wife and kids...No AC will not be a welcome addition to a 12 plus hour drive.
Rob m concord, MA

You DO NOT want to come down here to NC without a functioning AC this time of year...

I don't see how it could have anything to do with your boost problem. Have you checked your fuses? It could be that simple. Of course, it could be low on R134a... could be a bad compressor, could be a bad sensor... who knows.

I'm going to cry.

but first per bentley I'm going to brige terminals 1 and 2 of the high pressure switch with the engine running to see if "the refrdgeration circuit is empty"

Rob M

might want to check for coolant migration while you're at it.

The drill the connector mod has been performed but I suppose its easy to check..is that the migration you're talking about?

The bently procedure says there are 4 wires on that switch. There are only 3. There was a wiring change made in 2000. If you have the same manual as I do, look on page 97-329. Check fuse #5. Check for voltage on the A/C clutch when the switch is pushed in and that the fans turn on and the light. Check the wiring both at the clutch and at the fan control module (below the battery?).

For the pressure switch, the white wire is the control to the fan module. Black/Blue goes to V+ and brown/white goes to ground.

The 3 wires are B+, signal, and Ground. To test check the center wire by back probing with a volt meter. You can't bypass this sensor. The normal reading will be 50hz and between 25% and 50% on time. Volt reading will not tell you anything. Set meter to volts then press Hz button 1 time for Hz reading 2 times for % reading .The Hz reading tells you that the sensor is working the % tells you the state of charge.The state of charge/pressure must be above 20% I beleve for the compresor to turn on.

If this checks out ok You can by pass the ambent temp switch located under cowl panel on the driver side. This is just a temp switch not a sensor (will show open or closed when tested)also look at the wires to this switch I have seen lots of rodent damage to this wire.

Also be sure to look at the fuses on top of the battery pull out the 3 green ones look for burnt markes if there are replace the fuse holder.Very common problem.

Good Luck

Thanks for the additional info....I checked that ambient temp sensor. wiring looks good....some debris (not much) associated with potential rodents but no visisble damage...I'm thinking clutch at this point...the headlight dim a tiny bit (barely perceptable) for an instant when the ac switch is pushed in. this could be because of the fans kicking on of course but could it also be the clutch trying to engage but somehow stiff or siezed? I rapped on the end of the compressor with the switch on and the car running but there was no change. It was late but I swear I was getting 9 volts at the compressor with the car running and the switch off. then I was getting 0 volts with the switch on.....does any of this make any sense...I'm resolved to traveling without the AC but am eager to keep trying what I can to pinpoint the porblem......Rob M Concord, MA

I leave Sat@4AM MA > NC hoping for cold front. "kumbaya" will only last so long....

If the fans come on when the ac is turned on and the engine RPM flares slighty at the same time. I would think it is the fan control module located under the battery. To remove it you can just see the two 10mm bolts from on top (In front of battery behind headlight) remove them then it comes out from under the car.you might be able to get it from on top never tried. you dont need to remove the battery