535 A/C wiring question

BimBim2oo2 · Post by **BimBim2oo2** » Wed Oct 30, 2013 7:59 am

The other day my blower fan for my A/C unit would not shut off (this is the fan that sits in front of the condensor). For some reason the fan had a line that ran directly to the battery. Unhook it from the battery and it shut off. I believe there is a temp senser or switch somewhere in line with the fan that blew that or a switch.

Does anyone know where the temp senser for the fan would be located? I am assuming it is much like a engine temp sensor for the rad fan. Will stay on til it reaches a certain temp than closes.

My first question is. Is this normal? Should the fan be connected directly to the battery? If not where is the proper.

If this is not normal what is the correct wiring?

I have looked at Real OEM already and there is not much there in the form of guidence.

Thanks
Josh

Mike W. · Post by **Mike W.** » Wed Oct 30, 2013 9:55 pm

I had that on my first E12 and I never really tracked it down, IIRC I could stop it by turning the temp control to the off position, but I'm pretty sure it is a shorted diode in the wiring down by the compressor leading to the compressor. The temp switch should be located in the right hand radiator tank. On US spec cars, 530s got one, 528i's got two for a two speed fan.

BimBim2oo2 · Post by **BimBim2oo2** » Wed Oct 30, 2013 10:04 pm

Mike W. wrote:I had that on my first E12 and I never really tracked it down, IIRC I could stop it by turning the temp control to the off position, but I'm pretty sure it is a shorted diode in the wiring down by the compressor leading to the compressor. The temp switch should be located in the right hand radiator tank. On US spec cars, 530s got one, 528i's got two for a two speed fan.

I got it to shut off. Thinking it was the diode as well after I spent some time looking at the diagrams. I drove the car to work the other day and it started to rain so I am thinking some moisture got caught up in there.

The line that went directly to the battery had a 25A fuse in series with it. After further inspection underneath the steering wheel column was the same thing. Whether or not the second one goes to the AC or not I do not know as I have not traced it yet. I am honestly thinking of just ripping the AC out. Added weight and I never use AC to begin with.

Mike W. · Post by **Mike W.** » Wed Oct 30, 2013 10:12 pm

Ah, lets see, what's the elevation in Boise?

My current one, courtesy of a prior owner, doesn't even have but a few of the parts in spite of it coming that way from the factory. My first had great A/C and got used regularly, especially on Las Vegas vacations in August. Is yours factory air or aftermarket, they had a couple of different ones I believe.

BimBim2oo2 · Post by **BimBim2oo2** » Wed Oct 30, 2013 10:13 pm

Mike W. wrote:Ah, lets see, what's the elevation in Boise? My current one, courtesy of a prior owner, doesn't even have but a few of the parts in spite of it coming that way from the factory. My first had great A/C and got used regularly, especially on Las Vegas vacations in August. Is yours factory air or aftermarket, they had a couple of different ones I believe.

It is aftermarket.

Have you ever had a car with a aftermarket AC system?

Right now I am a bit confused on whether or not I can use the OEM lateral trim panel with a aftermarket system. The one on the car now does not line up right and to be honest I can not even find a picture of the current one on the car in Real OEM

This is the part I am wondering if it will work with a aftermarket AC

This is the current trim panel. It is one piece unlike the one you will typically see on a MT car with AC

Josh

Mike W. · Post by **Mike W.** » Wed Oct 30, 2013 10:24 pm

I've never seen one that looked like that and while I had an early car as a parts car one time, it was a looooooooong time ago. My guess is it's aftermarket, or an adaptation of a factory part, but I've never seen one like that.

The only cars I've ever had sort of aftermarket A/C in were e21s which often came with dealer installed air. It wasn't factory, but it wasn't aftermarket. Not the same parts at all, but available at the dealer.

BimBim2oo2 · Post by **BimBim2oo2** » Wed Oct 30, 2013 10:31 pm

Mike W. wrote:I've never seen one that looked like that and while I had an early car as a parts car one time, it was a looooooooong time ago. My guess is it's aftermarket, or an adaptation of a factory part, but I've never seen one like that.

The only cars I've ever had sort of aftermarket A/C in were e21s which often came with dealer installed air. It wasn't factory, but it wasn't aftermarket. Not the same parts at all, but available at the dealer.

I think I am just going to remove the trim panel off my 528 and give it a go to see if it fits. I did a measurement (can't say it was 100% accurate) but it appears that the aftermarket AC unit has the same dimensions as my 528. On my 528 I have a OEM panel so we shall see.

As far as the trim panel goes on my car I am puzzled to death on where it came from and who made it.