94 sse cold ac yesterday...today..not. comp is not engaged
 

My 94 acted weird yesterday.

new compressor last year.
Charged the system this year, I hit it with a can of chrge/oil/leak fix/find....it was cycling every 5 seconds or so. I hit it with another 12oz and it was cooling nicely in 100 degree heat with the roof open for two days. Compressor nice and quiet with no problems.
next morning...no cool.

this morning checked and the AC is not engaging the clutch...it is not trying. Checked underdash fuses..all OK. Checked all accessable connections and everything OK too.
All climate and fan controls working and OK.

Cant find any other fuse links etc....can you point me to any other fuse links etc that I can check?

any other suggestions? I have read the threads about jumping a switch on the firewall or accumalator but havent found those yet. I would like to check any other fuse links before I start jumping wires since that would be a new experience for me.

Dan

update....

ok...pulled of the master fuse cover.

checked all fuses there and checked the connection for the plug on the accumalator/dryer (not sure) two blue wires. Everything seemed tight and secure...moving the wires and plugs while car was running had no effect on the compressor engagment.

Maybe the refrigerant leaked out. Have you checked the pressure since it stopped working?

thanks Ted....no I havent checked the pressure...no gauge.


UPDATE

OK..I got brave and pulled the two (blue) wire plug out of the accumalator and jumped the connections while the engine ran and controls set to auto air.

The compressor engaged properly and ran without any noise, sounded great. I let it run for a few minutes but the air temp at the vents did not cool so I assume the charge is down probably from a leak that developed

I also assume from other threads and posts that the comptressor may be at a low charge condition to the point that the compressor is not engaging because of the low charge. If this is normal default/safety behavior for the system...then thats good news I guess.

Can some clear the air......low charge...no go? This would eliminate the probability of a bad fuse/switch/relay...yes?

At this point...I am thinking I need to get to somebody that can check for a leak unless you gurus have another suggestion.

Thanks in advance.
Dan

you hit it with some stuff that worked as a leak finder? should be able to see that stuff with a black light.

I don't know much about air conditioning but I'm 99% sure that there's a pressure switch that prevents the compressor from running with low refrigerant.

Yes, there should be a pressure switch on the low side of the system, low pressure cut out interlock with the a/c clutch engae permissive ckt. Too low of a refrigerant pressure=clutch engage inhibit. This is all controlled by the PCM.

thanks everybody.

the leak finder and a black light is next.

Also...last year when I installed the new compressor...there was an issue.

where the two bolts mount the hose block to the compressor...there was a little difference in the one going on and the one coming off. There wads a little bit of an offset where one of the lines met the compressor surface. We had to add one extra washer/spacer to that area to get it to seal up.

afterwards...we ran a vaccuum test for about twenty minutes and it held fine...fully charged the system and it worked great for almost a year without a problem.

This is probably a good first place to look for a leak...maybe one of the bolts loosened or something....we'll see.