Challenger Aircon Fan Query

[anderssenian]

I have a 2001 Mitsubishi Challenger and have noticed that the aircon electric fan doesn't come on when the compressor comes on. The fan does come on the first time I push the aircon button but doesn't come on again after the compressor stops and restarts. I thought it should start up each time the compressor operates but the dealer claims it doesn't have to. Can anyone verify that the fan may not always operate when the compressor operates? I was caught in a 5 hour traffic jam in Brisbane some weeks ago and the engine got very hot with the aircon on. Turning it off brought the temperature down - prompting the question.

I am obviously referring to the electric fan in front of the radiator - I think its for whats called the condenser that is mounted there

[ticky]

Im not familiar with the Challenger system, but most Electric fans these days are operated by a Thermo Switch.

My last Commodore had the fan come on with the Aircon but would come on without the aircon if the temp started to rise.

If it is wired to only come on from the Thermo switch, then it may not necessarily come on just because the Aircon is on, but if your engine was getting hot, it should have come on regardless.

Have you had your Radiator removed at any time? My son had heaps of problems with his car overheating after he had a new radiator put in. he brought it to me and I discovered the thermo fan wasnt coming on. while poking around to find a live wire when the ignition was on so I could do a quick and cheap fix, I discovered the plug that should have been plugged in after the new radiator was installed, but wasnt

Steve

[anderssenian]

Thanks Steve. Havent had any change to the radiator but have always had it flushed at appropriate intervals. I have had cars where the electric fan cuts in each time the aircon compressor cuts in which is why I feel the Challenger should work the same way.

[ticky]

I would suggest taking it to an auto electrician and
A. Find out when it should come on.
B. Find out if it is coming on when it should.

Steve

[Roach]

Most condenser fans on cars run on a high pressure switch, so when compressor starts pumping the fan will kick in when pressure reaches a certain amount on the high side. If it gets too high It will cut out compressor. I'd suggest getting the refrigerant level checked cos if their isn't enough refrigerant it may not be building enough pressure for the fan to come on. Therefore having an inoffecient system.

Is the air temp in cabin still very cold coming out vents when ac is on?
Does the challenger have a sight glass at the drier to check for bubbles?

Pressure switch could be faulty, Other option is to bypass pressure switch and hard wire fan to comp circuit, or your fan has seen the end of days and replace it.

[anderssenian]

Thanks Roach. Yes I think the answer is to get the system checked out by an aircon specialist. It still blows reasonably cold air but the rise in engine temperature in the Brisbane traffic jam with the aircon on really surprised me. If I could have, without creating irate drivers behind, I would have got out and checked then if condensor fan was operating!