: 90 Brougham A/C died



Orph
05-10-05, 08:51 PM
I wonder if anyone can help me with the A/C in a 1990 Brougham that suddenly stopped working great. :annoyed: The A/C clutch won't engage now, although the belt spins when the engine is running and no strange noises are coming from it. Does the sudden stoppage with no noise mean the compressor has broken? I can't find a bad fuse in the fuse box. I can't find anything that looks like a relay in this car, which has automatic climate control. Do I have to get pressure gauges to check the coolant? :hmm:

Thanks.

Orph

gtm2u
05-11-05, 07:26 AM
I wonder if anyone can help me with the A/C in a 1990 Brougham that suddenly stopped working great. :annoyed: The A/C clutch won't engage now, although the belt spins when the engine is running and no strange noises are coming from it. Does the sudden stoppage with no noise mean the compressor has broken? I can't find a bad fuse in the fuse box. I can't find anything that looks like a relay in this car, which has automatic climate control. Do I have to get pressure gauges to check the coolant? :hmm:
Thanks.
Orph

I don't know the specifics of you car but may be able to give you some help. With the engine not running and not uncomfortably hot, reach down and try to rotate the centermost part of the compressor clutch. This is direct bolted to the crankshaft/swashplate and there should be some resistance and no clunking or other _ugly_ noises. Note the technical term ugly. :)

This may or may not work: turn the key to on, the A/C on with the blower on low, repeat trying to turn the clutch. If you cannot then in all probability the clutch and compressor are _not_ at fault. Key to off.

If you are comfortable with hooking up a jumper wire to the compressor clutch you could apply battery voltage and see if any of the A/C parts under the hood get cold or have cold air from the ducts inside the car. If it does then you could have an electrical failure, a module, a vacuum motor, mode switch etc. failure or open circuit such as a fuse.

A manifold set could tell you if the pressure is too low and needs a recharge. Most modern systems with have a low pressure switch which will prevent the clutch from engaging and not destroying the compressor. If you can locate this switch you can test for continuity and 12v, this can be used as another source to energize the clutch. If you have no voltage at this switch then the problem could be an open electrical circuit or failed component. You may be able to rent a manifold set from some of the chain auto parts stores though hooking things up wrong could cause serious injury. If you plan on keeping the car and doing repairs then you will have to bite the bullet and buy a manual with a good schematic and troubleshooting section.

Keep us posted on what you find.
GTM2u

Orph
05-11-05, 01:11 PM
Thanks for help on this. I think you're right about getting a repair manual.

I will try what you suggest and report back. Many thanks. :worship:

Orph

sleekster
05-11-05, 04:08 PM
could be a leak, i beleive there is a switch that senses when the system is low on freon and will prevent the compressor from turning on, the freon is also the lubricant so without a sufficient amount the compressor would burn up.

Orph
06-04-05, 07:51 PM
Sleekster and gtm2u, you both were right. It was a leaking Schrader valve and the low pressure switch shut off the compressor to prevent damage. I had to convert to R-134a but at least the A/C works now.

Thanks for your help. This is a great forum. :)