Hey there! I just got my hands on a slightly damaged E66 and I'm trying to fix it up. One of the problems is the electric fan, which was busted. I replaced it, and now everything is working fine except for the control wire, which is black and green with yellow stripes. No matter what I do—turn on the engine, turn on the ignition, turn on the fan—through a scanner, it always shows 0.04v. Any suggestions?
Where does it receive its signal and is there a nearby connector where I can test for continuity? I thought the line could be pinched, but I can't seem to locate any pinch. There are no additional electrical problems with the vehicle, despite the damage.
How to wire an electric fan
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felix_okaforp
- Posts: 11
- Joined: Mon Apr 06, 2026 7:44 am
Re: How to wire an electric fan
The duty-cycle energy converter (DME) sends a pulse-width-modulated (PWM) signal to the fan circuits, which regulates the fan's speed. You can't use a voltmeter to check it.If the fan has failed, there should be a code in the DME (no CEL set, because this failure is not an OBDII protocol issue). Read the codes to find out.
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emmatorrescj
- Posts: 7
- Joined: Mon Apr 06, 2026 7:44 am
Re: How to wire an electric fan
Just right. A DME code for FAN ACTIVATION (or something similar; I can't remember exactly what mine stated) will be sent to you.
Upon starting the car, DME also checks the fan. If you're fast enough, you can get out of the car just in time to witness the fan start to spin gently as soon as you start the engine. But hurry, it doesn't last long at all.
Upon starting the car, DME also checks the fan. If you're fast enough, you can get out of the car just in time to witness the fan start to spin gently as soon as you start the engine. But hurry, it doesn't last long at all.
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felix_okaforp
- Posts: 11
- Joined: Mon Apr 06, 2026 7:44 am
Re: How to wire an electric fan
Oh, that's helpful information; I've never dealt with such complex electronics before.
I am using Foxwell NT530+ for BMW, in case it makes a difference, and I just removed this fan from my e65, which also worked flawlessly (the e65 went for parts because I couldn't sell it, but everything was good). The code is 41F1.
And although I can't say for sure that the fan was to blame, the only electrical damage was a ripped off connection on the outer temperature sensor (the one that sits forward of the wheel); I'll solder a new one on.
I am using Foxwell NT530+ for BMW, in case it makes a difference, and I just removed this fan from my e65, which also worked flawlessly (the e65 went for parts because I couldn't sell it, but everything was good). The code is 41F1.
And although I can't say for sure that the fan was to blame, the only electrical damage was a ripped off connection on the outer temperature sensor (the one that sits forward of the wheel); I'll solder a new one on.