DIY Chatroom Home Improvement Forum

DIY Chatroom Home Improvement Forum (http://www.diychatroom.com/)
-   Automotive Repairs (http://www.diychatroom.com/f46/)
-   -   ac comp doesnt kick on (http://www.diychatroom.com/f46/ac-comp-doesnt-kick-182075/)

noquacks 06-18-2013 05:20 PM

ac comp doesnt kick on
 
OK, nother problem with same car- 88 sunbird. Aftermarket ac system. No cold air, so I checked for voltage and no voltage to comp. All I can meassure is static psi, which is usually useless, but its about 110 psi.

Dont want to indiscriminately add R134a unless I check other stuff out. Why is comp dead? Its power source is the alternator, and I folowed it to the relay after which, no power. Theres a blue wire going to the cowl area, I figure, to the evap unit/TXV valve. What do I do now, people?

del schisler 06-18-2013 05:35 PM

Quote:

Originally Posted by noquacks (Post 1203545)
OK, nother problem with same car- 88 sunbird. Aftermarket ac system. No cold air, so I checked for voltage and no voltage to comp. All I can meassure is static psi, which is usually useless, but its about 110 psi.

Dont want to indiscriminately add R134a unless I check other stuff out. Why is comp dead? Its power source is the alternator, and I folowed it to the relay after which, no power. Theres a blue wire going to the cowl area, I figure, to the evap unit/TXV valve. What do I do now, people?

a few thing's , if low on feron the unit will not kick the comp. on, does the comp. lock on of is is just free spinning ? did it just quick? Best if you know some one to check the freon in the comp. i bet it has a small leak which when it get's to low it will not lock the comp. in ? good luck

noquacks 06-18-2013 06:13 PM

Thnaks, Del. I should have mentioned that I can spin the clutch by hand easily, and it turns prettu smoothly, and nice. I dont need someone to check the freon in the comp- he wouldnt do anything other than what I could, or you could- no way to know actually, unless one empties all out and weighs it.

JackDidley 06-18-2013 06:50 PM

Does it have a low pressure switch ? That will keep it from running if the pressure is indeed low. If it was mine, I would be tempted to apply 12 V to the clutch. That will make the compressor run and you can check pressure. Not being able to actually see what you have, not so sure.

cjm94 06-18-2013 07:24 PM

At 110 psi it should kick in and is probably around a full charge. You could have a bad psi switch. The low side ones tend to fail you can jumper the wires if it kicks on replace the switch. If its a dealer installed after market you may be able to get a wiring diagram from gm.

noquacks 06-19-2013 06:15 AM

Good tips. Where are these low pressure switches located? A picture of one would be great, if we could find one on the web. Yes, I could jump the lead wire with 12v too......

cjm94 06-19-2013 06:50 AM

They are usually located on the low psi line near the accumulator-filter/dryer.

noquacks 06-19-2013 03:01 PM

OK, then, theres no pressure switches anywhere. I heard some comps are like that. Mine is a V5 type- I think it steadily compresses as opposed to the click on/off styles, if that matters.

So, without a low pressure switch, maybe I should try to hot wire the comp from the battery to start it. Then, I can seee the running psi's and go from there, unless theres a beter idea....

meanwhile, lets not forget about that blue wire lead going from the relay thtough the firewall, ending up at the ac controller (a tiny black plastic box, about 2" cubic. I believe thats the controller). I suspect that is responsible for a signal to activate the compressor(???)

noquacks 06-19-2013 05:22 PM

Im bringing it to my buddy ac mech tomorrow........sheesh.

noquacks 06-20-2013 03:43 PM

Whew- ac mech found it was a fuse. There are 2 fuses on my system. Thought I would report back. Thanks, people.

noquacks 06-21-2013 03:58 PM

OK, I had cold ac for a day. Fuse blew again. Anybody know what could be the likely cause?

Thaks

Bigplanz 06-21-2013 06:17 PM

Bad ground. Internal short in a component? I'd check the ground first.

noquacks 06-24-2013 08:08 PM

Quote:

Originally Posted by Bigplanz (Post 1205226)
Bad ground. Internal short in a component? I'd check the ground first.

After 2 days poking/testing around, looks like grounds are OK, but the microswitch may be bad cuz the spade terminals are "burnt". Im removing it and getting new, but man, hard to find. Its a "Cherry", E-14. Gonna take it to NAPA. I hope/believe this is the culprit.

bad /weak switch can cause amps to go up, heating up wires too much, right? No other thing to blame in my ac system thus far.....wish me luck, people.

noquacks 06-27-2013 07:31 PM

OK- finally switched out 2 burnt spade ends- gotts be the culprit, adnt ehswitch ohms out OK at about 0.2 ohms. Started car, cold ac. Will test it tomorrow- driving it with ac on all the way to work! Whew- tired of drives in 90 deg heat!

lets hope it doesnt blow! (no voltage drop either across the switch terminals for 2-3 minutes- may require more time, though)


All times are GMT -5. The time now is 09:03 AM.


Copyright 2003-2014 Escalate Media LP. All Rights Reserved