A/C Always On - Ideas?

Glenn3s

Member
:
2004 3s
Hi all,

On my '04 5-door, the A/C has just started loving itself. It's on (compressor running) whether the A/C light on the swich is on or not. The light toggles on and off when I push it but the compressor stays on. Anybody seen this and/or have any ideas for diagnostics and fixing (uhm)?

Thanks.
 
if your vent selector is at noon (foot) or anywhere after that it automaticaly turns the compressor on. part of the dehumidification system built in... regardless of the light... its in the manual
 
Knew that

if your vent selector is at noon (foot) or anywhere after that it automaticaly turns the compressor on. part of the dehumidification system built in... regardless of the light... its in the manual

Yup, it's in the manual. That's why I should have used the word "always". As in, any position of the vent selector, any position of the fan switch, the compressor is "always" on. Any other thoughts?
 
mmm ok that is different..... i am not 100% sure on this but i would imagine there is a relay that turns the compressor on and off... it could be stuck? (happens with mechanical relays often enough that it could be that simple) though where this relay is i have no idea... see if we can't dig up a wiring diagram or someone that has the full boat manual and trace out the A/C circuit and see what could be causing it to stay on.
 
The relay is inside the under hood fuse/relay box located in front of the battery box.

this shop manual link (I believe it's a European manual but it appears to be similar to our cars in the a/c section) has a/c information and a basic wiring diagram plus some check and test procedures. Maybe it will help you figure it out. I don't have the answer but making voltage and resistance checks should help you locate the problem.

There appears to be 2-3 identical relays in the box, I didn't pull them out to verify that, I'm going by the size. You could try swapping them around to see if the relay is bad.

Clifton
 
I'll try it

OK guys, thanks. I'll check the relays this weekend. If I find anything really good I'll post it.
 
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