Air compressor question?

[mgmgmg]

I have a 94 ltd just a winter beater. just wanted to see if the air still worked but the compressor will not "click or cycle. I check the level of 134a freon and no leaks....also the temp control orange light works. just wanted to know if theres a fuze or anyway to get the compressor working again?

 

[boggs1227]

i would check the a/c relay under the hood .

 

[muhl5443]

if the relay is good. you might need a new compressor.

 

[mgmgmg]

the black fuze box passenger side under the hood...top right fuze ?

 

[boggs1227]

try to take the relay out and tap it hard on something ( don't break it of course....) ....sometimes the little metal strip in the relay will become corroded over and contact will not be made .

or ..... your sig said you got 2 94's right ?? then just take a relay from the other truck and swap it to see if it's the relay in question .

 

[marragtop]

Use a test light to see if you are getting power to the compressor.

 

[Maniak]

to check the compressor clutch itself just take 12V and ground and run them to the two connectors on the top of the compressor clutch (doesn't matter which is which).. If the compressor starts to run then your low on freon (low pressure), low pressure switch/connection is bad, or the relay/wires have an issue.

~Mark

 

[BrooklynBay]

Check your pressure with a manifold gauge set.

 

[mgmgmg]

I did a swap with my other 94 no dice. i know I have freon because it shows 30 psi. im quessing its the compressor. not worth replacing only when i drive in winter. Mark this low pressure switch wheres this located? i see the switch ontop of compressor . just wanted to ask ... low pressure switch....

 

[Maniak]

The low pressure switch on on the receiver/dryer (I forgot the proper name for it on the X).. It is screwed into it. It the connector you normally have to short when you put freon into an empty system to get the compressor to start running before you have enough pressure in the system.

I'd start with jumping 12V and ground to the compressor.. If that works then the compressor/clutch is ok...

~Mark

 

[mgmgmg]

could u explain more with the jump start 12v? Just unplug the switch ontop of the compressor and then ?

 

[Maniak]

Exactly.. unplug that connector.. and there are 2 pins there.. with the truck running, put 12V to one pin and ground to the other.. If the compressor/clutchis ok it will start to run.. It doesn't matter which gets the 12v and which gets ground.

~Mark

 

[mgmgmg]

Ok dumb question like a 12v battery charger.... im confused with what source of 12v to use ...sry man....... u dont mean a 9v battery ?

 

[Maniak]

I mean run a wire from the positive side of the battery to on pin on the compressor and run a wire from the neg side of the battery to the other pin on the compressor.

~Mark

 

[mgmgmg]

ok i plan and doing the 12v wire from the battery to the compressor. Just one question will this short out any thing? will i see sparks flying here. just a concern. Should i have the ac on also?

 

[marragtop]

Before trying the jumper, just use a test light on the plug wire going to the compressor to see if you are getting power.

 

[Maniak]

That works too.. If your not getting power to the compressor it won't turn on. I pretty much always do the jumper wire test on the compressor first so I can eliminate the compressor from my troubleshooting.

I don't think I've ever seen a spark when I jump 12v & ground to the compressor. You bascially just doing what the a/c relay is doing.. putting 12v to the compressor. IIRC, the ground wire to the compressor is always grounded..

You don't need to turn on the a/c since that is what your doing with the wire.. If the clutch/compressor it will start to spin (the inside of the clutch) and then you know thats not your problem.. then start looking at electrical issues..

~Mark

 

[mgmgmg]

ok heres the deal i did the 12v test but i used pretty thin wires. what happened it clicked once very fast thats it. what type of gauge wire should i use? Now light test i dont know what that is or do i need a special tool for that. But it clicked once and thats it.

 

[Maniak]

click once if the truck is off is fine. . If the truck was running, and you put the wires there you should see the center of the a/c compressor clutch spin with the rest of the pulley..

if it does that, then you can forget the a/c compressor being your issue..

~Mark

 

[mgmgmg]

I did the 12v test again it cycles fine! what could the problem be?