Service A/C Light...how to disable?

[Guest Kitskaboodle]

My Service A/C light came on this morning on the way to work.

First time it has ever come on.

Anyways, I dont plan on using the A/C for a while so I would like to disable the light until I do a re-charge in a few months. Is there a fuse I can remove to disable it?

Thanks, Kit

[Guest Mc_Reatta]

Resetting the BCM codes should turn the light back off. May have to disconnect the battery to do the reset though. 90s owners say they can't reset this code via diagnostics.

As to whether it will come back on is harder to answer. You must have been using the AC in some fashion to turn it on in the first place. Either the defroster was used or the control is in auto and it decided automagically it needed the AC when cabin temp got too high.

Not having a CRT, you don't know if you have a low refrigerant condition or a very low refrigerant condition which will latch. (You can check the code number in diagnostics though)

Don't think pulling the AC fuse # 19 will prevent the light from coming on if the BCM wants to turn the AC on for some reason as it will give a low pressure warning to the BCM no matter what by pulling the 12 volt signal away.. But you can short the pressure switch to tell the BCM that there is a charge, and pull the compressor clutch relay (J) in the underhood relay center so it doesn't self destruct by trying to run. That should work.

[charlie1]

Go into the CRT and change the mode to Economy or Heat until you can service the AC system.

[padgett]

Depends on whether the message is "Low" or "Dangerously Low" - the second requires disconnection of the battery to clear. Once clear you will need to set the system immediately to ECON (default after R&Ring the battery is AUTO) to keep it from coming back.

[Guest rendrag]

Try a piece of black tape on the IP.

[Guest Kitskaboodle]

I have never used the AC other than servicing it once early last summer.

(I anticipated using it but never ended up doing so)

I do however used the front defrost button/medium fan setting a lot on these "chilly" California mornings. That's probably what triggered it.

Will disconnect battery to see if it goes away.....

If not, I do have some freon lying around so maybe I'll fill it (again) this weekend.

Thanks, Kit

[ptt]

Id find out where the refridgerant is going first. From first-hand experience theres only one way to deal with Auto AC. Do the repairs right initially and it only hurts once ($)...just adding gas is just wasting money if you dont fix the leak first.

[Guest BAABUICK]

If you don't plan on using the A/C for a while, simply disconnect the compressor (I did this every winter). Clearing the code should take care of the A/C light.

[padgett]

If it is just the "low" (code 446) warning, it can go away (446h). Can happen on a cool day particularly at freeway speed & 134. The "dangerously low" will keep the light on until the battery is disconnected. I take it this is a 90 or 91 ?

I have a local shop that is very good at diagnosing, it is possible when you had it serviced, a schraeder valve started seeping particularly if the plastic cap was not replaced.

[waltmail]

I got a piece of advice from an a/c guy awhile back. I cannot vouch for its credibility. On the back side of the compressor, there is a manifold that is sealed by 2 o rings. If the A/C is not used for quite awhile, the O rings tend to flatten out and dry up causing a source for refrigerant leaks. This would be evidenced by oil on the oustside of the manifoild. Just firing the A/C up once in a while will allow lubing of the rings in this area and possibly prevent the degradation process. Can't hurt. might not help.

[Guest Kitskaboodle]

If it is just the "low" (code 446) warning, it can go away (446h). Can happen on a cool day particularly at freeway speed & 134. The "dangerously low" will keep the light on until the battery is disconnected. I take it this is a 90 or 91 ?

I have a local shop that is very good at diagnosing, it is possible when you had it serviced, a schraeder valve started seeping particularly if the plastic cap was not replaced.

I have a 90.

Oddly enough, when i drove home from work yesterday the light was off and never came back on.

Kit

[Guest Mc_Reatta]

Sounds like your just a little low on charge. You'll be OK til you turn the defroster on that next chilly morning.

[Guest Richard D]

If you have 134a I reccomend you put a small charge in it and use it. Keeps all the stuff lubed, freon moves with the oil through the system.

[padgett]

Need enough of a charge to carry the oil, too low won't (why the cutoff). HR6 has two different thicknesses of O'rings, GM has about six. Think you need a green and a red.

[Guest tomt]

Had the same issue:

Just switch to Economy setting till you get it checked. Don't have a Reatta anymore, but remember that one.