MCR

Hey Kyle...

I had a fan that only ran slow and eventually refused to turn on at all. I traced the control wire back to the dme where I found the pin corroded. There was next to nothing left of just that one pin at its base down in the dme plug houseing. When I removed the plug... The pin came with it!!

I bought a used dme having the same part number and had the original cloned for $240.

KyleB

Thanks for that! this is what I'm in the process of checking now, no corrosion on the PWM signal wire coming off of the DME. I think the PWM signal is on pin 4 of the DME, do you remember if that is correct?

was this an E60 you had your problem with too?

RCB

I just replaced my entire fan assembly due to cracked fan blades and my motor was fine. I'm not sure how if the blade assembly can be pulled off the shaft without damage or if your car uses the same motors but if so I saved my old motor. My car is 08' 535xit with 850watt round fan motor. If it looks like it would work let me know.

MCR

Bottom row, fourth from the left. Dunno what pin number it is. 2004 545i

KyleB

thanks for the offer. my car is an '04 build M54, there are a couple of different versions of the fan, I think your turbo car uses a different fan assembly. thanks again though

KyleB

awesome, thanks for the info

MCR

The harness plug comes apart. There are two strips of wires housed together. I would disassemble the plug and inspect the female pin. I don't remember the wire color pattern, but it will match the colors at the other end where it connects to the fan.

Seeing I had a very weak connection prior to me removing the plug and the pin coming with it... I would guess a weak connection via a loose female pin could cause similar issues.

KyleB

just got done opening up the E-box and inspecting the yellow/red wire that comes off of the DME and goes to the fan. E-box and DME were bone dry (this is good), all pins in DME are clean, DME connector is clean, yellow/red wire is completely intact. also checked PWM signal wire at the fan connector, all is well there. I am confident it's all in the final stage unit of the fan, which is NOT an uncommon failure in late model BMWs.

I'm going to put in a new fan and see what happens.

MCR, thanks for the tip. I was sort of planning on checking that but your photo definitely motivated me more. FYI everyone, keep your climate filter housings clean!!! if you don't they back up with water, and the E-box sits right underneath the filter housings. if water gets inside of the E-box that up there is what happens

and finally, I can't wait for this year to be over. 2016 sucks a werewolf's ass with hoisin sauce.

MCR

My ebox coverings and ducts etc were completely free and clean. When I first bought the car, I found several of the cover screws undone so water likely got under the cover when driving in rain. In any case, I put a plastic bag down before installing the cover for extra protection.

I would bet its your fan itself also... Let us know how it goes!

KyleB

smart move, I started doing that after we had a rash of E36s come in with water logged DMEs after going through car washes. This was back before EWS came into play and you could freely swap DMEs from car to car. I used to wrap the replacements with a plastic bag before putting them back in the E-box.

Bummer about the loose screws. It's funny you mention that too, I found one screw loose on my E-box cover, and sure enough there was a slight water stain at the gasket right were that screw is. Thankfully the surrounding screws were nice and tight so I didn't see any signs that water ever entered the E-box.