Has anyone successfully figured out what is the cause? I have looked through threads that touch on this, but I wanted to try to narrow this down.

Does the AC ever make the low speed fan stop, or is it always the fan stopping the AC.

Is there a common switch that can cause both symptoms?

Based on what I have been reading the low speed fan is likely the cause of no AC at this point (though I have not run the car to see if it kicks on due to temp) I know that just a few weeks ago it was working fine.

EDIT: (see below) next step seems to be to visually inspect the low speed resistor to make sure it is OK. The images I see of the failed ones suggest they are very obviously bad when they don't work. If it looks OK, I will check continuity and move to the next (unsure what ATM) step.

I don't want to waste time on the AC if it is the fan, but conversely if it could be the AC, I want to trouble shoot that obviously.

The pressure switch had three wires. One wire I got what seemed to be a weak voltage (test light not bright). Are these switches open ground? Can they be shorted to test the ac? If so, which wires? (Looked like 2 black and 1 brown) There was not much room and I am not tiny.

Car is a 2003 MCs.

I checked the fuses, looked OK.

Refrigerant is just under 90 lbs on both sides (compressor won't kick on, it was a bit lower, but I put in a little to try and get lucky). Low fan won't kick on.

What is the next suggested step. I would love to fix this myself, but my bad back wants me to pay someone. (brain says no, fix it yourself)

I am wondering, do I need to pull the radiator to look for a bad resistor? (Can I just jump something to check?)

Do I become a parts monkey and start changing things (Like pressure switch, etc.)

Guide me or my back will win the battle.

EDIT: My buddy is a prep tech at a mini dealer. He is suggesting the first thing he would check is the low speed resistor on the radiator. Since they are known for failing, there is pressure in the system, this is step one.

Wife needs the car, so no more work today.

 

No. The A/C logic turns on the low speed fan. If the low speed fan resister is open the low speed will not turn on and when the temps and pressures rise, then the high speed fan kicks on. I think that no low speed put undo strain on the compressor and components and clearly makes the A/C less efficient but our systems usually fail because the hoses or compressor clutch fail and not mostly because the fan is bad. Frankly I think there are a LOT of Minis out there with no low speed fans and the owners don't have a clue. Fortunately with the post 2003 Mini's the external resister works and is easy to install. On the pre-2003s (the ones with two fan plugs. One large and one small) the fix is changing the assembly as to even fix it you have to remove it and at that point a new fan at $80 seems the way to go for most people.

Is your compressor coming on? If not, it is usually the whole compressor that need to be replaced although occasionally a low pressure or high pressure condition can cause it not to come on. But then it would usually come on for a while and then shut down. It could also be a sensor but that would be unusual too.

Rich

 

Thank you Rich. With the probability being the compressor, I am prepared for that, but I just want to check everything first.

Do you know any way to force the compressor to run, but jumping wires or something. It would be nice to confirm it before I spend the money.

 

To the best of my knowledge, the ac should still operate with the low speed fan blown...it may not be as efficient, and the higher pressures in the ac system may put more strain on the compressor, but it should still run unless you have a secondary problem. My ac ran fine with the low speed failed, but was not as cool when the car was stopped. Many folks have reported that runnng the ac too long with the low speed fan blown did cause the ac to fail...or have been told this by the repair shop/tech.

 

No.On mine and another one I played with it was the compressor clutch so no amount of jumping could get it to come on. And we couldn't source a clutch without a compressor. Unfortunately it is a big job with expensive parts. $1000-1200 even at an independent and a bunch more at the dealer.

But you should bring it to someone who knows A/C systems and not simply tell someone to replace the compressor. And it should also be someone who has worked on Minis as, again, it is no small job to get to the compressor.

Rich