Car A/C weirdness

June 18, 2005 7:23 AM

Strange things are going on with my car's air conditioner.

I'm driving cross-country from Fort Lauderdale to LA (almost there now!). While still in Florida my car's A/C went out... the blowers worked, but there was no cold air. I took it to a shop, who deduced an electrical problem, replaced a fuse and a relay and sent me on my way. The air conditioner worked well after that.

Ever since then, when I turn off the car and take the keys out of the ignition the air conditioner will still stay on. Not every time, mind you, but occasionally. Leaving it alone for a couple of minutes, then moving the car and shutting it off again seems to fix the problem, but just repeatedly starting and shutting down the car when the problem first manifests doesn't. I'm not noticing a correlation between when the problem happens and other factors (e.g. length of time driven, number of miles driven, etc.)

In case any of this is relevant: It's a '94 Honda Accord, 114,000 miles, and was just fully serviced (the 90,000 tuneup, timing belts replaced) earlier this week. Taking it to the shop where the airconditioning unit was fixed isn't an option; it's in Tampa and I'm writing this from Arizona.

posted by the_bone to travel & transportation (6 comments total)

Try Car Talk
posted by growabrain at 7:32 AM on June 18, 2005

I've noticed that older Hondas have loud fans that run for a while to cool the engine after you turn the car off. People always used to tell me I'd left my Civic Wagon running in the parking lot when it was just the fan.

Looks like this is still the case even with the hybrids.

Is it possible that the fan is either powering the A/C or just continuing to send already cooled air into your car's interior for a while after you turn it off? Can you hear and see that fan running?

Looks like the Edmunds Accord forums are pretty active. Might try over there.
posted by climalene at 8:04 AM on June 18, 2005

Is it possible that the fan is either powering the A/C or just continuing to send already cooled air into your car's interior for a while after you turn it off? Can you hear and see that fan running?

Hmm. Yes, the fan is still running even though the car is shut off... however, cold air is continuing to be generated and all indicator lights for the A/C remain on. I've left it alone for up to 5 minutes at a time while this was happening (didn't want to try any longer than that and risk running down the battery) and it didn't shut off of its own accord (a pun! ha!). I needed to drive the car a short distance and turn off the ignition again.
posted by the_bone at 8:27 AM on June 18, 2005

Man, I know nothing about cars or electricity, but I wonder if somehow the mechanic messed up the job and hooked the A/C up to whatever circuit the fan is on. This does sound like an intriguing Car Talk question.
posted by climalene at 8:53 AM on June 18, 2005

If the engine is turned off there is NO way the A/C is truly operating. The A/C compressor is driven by the engine.

Is there air blowing into the interior of the auto? If not, what you are probably hearing is an electrically driven fan under the hood that is controlled by a thermostat. It runs depending upon temperature rather than whether the engine is on.

If air is still blowing into the interior after the car is completely shut down and the keys are out of the ignition I bet you've got an ignition switch that is remaining in the accessory position even when the key is remove. When you have the problem with the A/C will the radio also come on?
posted by Carbolic at 9:01 AM on June 18, 2005

Carbolic speaks the truth. No A/C without a spinning engine.
posted by Kwantsar at 10:17 AM on June 18, 2005