Does e-Box Fan Run On a Relay?

[Jehu]

My e-box fan is not working.

My DME's are overheating in this Summer heat and when they get hot enough the engine runs roughly at idles.

The reason I connect them is I have two DME's .

I can swap in a cool unit and the idle smooths out.. then I can replace the DME after the hot one cools and again the engine is smooth at idle.

Perhaps the DME units suffer from some weakening solders on the circuit boards.

I also discover there is a relay socket lacking a relay so wondered if the e-box fan is run off that.

All the wiring for the fan and tenp sensor seems to be intact.

I tried searching for "ebox relay" but didn't actually locate any specific reference to one.

[shogun]

we discussed that here 2 years ago http://www.bimmerforums.com/forum/showthread.php?2125097-Fan-Blower-Sound-Behind-Glove-Box
My E32 has a temp sensor in the e-box and runs on 2 speeds, but apparently the E34 onlu on/off

Old thread here about that http://www.bimmernut.com/forum/showthread.php/23732-There-s-an-E-box-fan

[Jehu]

we discussed that here 2 years ago http://www.bimmerforums.com/forum/showthread.php?2125097-Fan-Blower-Sound-Behind-Glove-Box
My E32 has a temp sensor in the e-box and runs on 2 speeds, but apparently the E34 onlu on/off

Old thread here about that http://www.bimmernut.com/forum/showthread.php/23732-There-s-an-E-box-fan


Thank you..

I have since found the missing relay is a White five blade.. it'll be interesting to see what connects through it.. I've been driving the car for over two years without it ..

So as far as the e-box fan then if its wiring is intact yet it fails to operate the motor is likely dead?

[shogun]

Can be several reasons: unplugged connector because the motor made noise, temp sensor defective, wiring, fuse,.....

[genphreak]

Never oil the sintered bearings in electric motors. Only roller bearings can benefit from oil. Sintered ones will become worse. If there are bad bearings, the fan will be noisy and may not turn smoothly. Best to replace the motor. I'll do this one day and update, I found some rare 12V/3000rpm (low speed) motors to suit my e46 and will get into the e34's ebox too as I have to do the cabin filter soon... maybe it will be the same