Help needed ... Electrical Issue

[pgunter]

Hello,

BMW Z3 2.2i Sport 2001.

Not that often I seek help, but this has stumped me.

From the beginning,

I changed the wing mirrors and a few weeks later they stopped working, Issue traced to a faulty motor I assumed, so motor changed but fuse 24 the 10A still decided to blow. During this time the heater blower kept working even with the 10A fuse blown.

The other day the heater motor decided to stop working. It just died, also the issue of the mirror fuse still has not been sorted as it still blows.

The question is, has anyone come across a common issue wit this circuit. I find it very hard to find any articles on it. The wiring diagram is attached. Any thoughts would be much appreciated. I am not 100% with electrical terms, almost need a car electrics for dummies book.

I had help from Lees father Trevor for a bit yesterday and I had already pulled the dash apart tracing wires. We disconnected the mirror motors, fuse blew.
We disconnected the heater motor, fuse blew.
We reconnected the lot hoping it might have been a connection.. nope fuse blew.


Any help and any pointers appreciated.

@t-tony you ever come across this before ?

 

[Lee]

Because the mirrors share this circuit have you tried disconnecting the switch's too?

I would also look at the wiring of the mirrors to see if any of the wires are shorting.

 

[pgunter]

Lee,

Disconnected and also changed the switch. No joy. Next on the list is door cards off. Just incase a wire is shorting on the bodywork.

 

[t-tony]

Hello,

BMW Z3 2.2i Sport 2001.

Not that often I seek help, but this has stumped me.

From the beginning,

I changed the wing mirrors and a few weeks later they stopped working, Issue traced to a faulty motor I assumed, so motor changed but fuse 24 the 10A still decided to blow. During this time the heater blower kept working even with the 10A fuse blown.

The other day the heater motor decided to stop working. It just died, also the issue of the mirror fuse still has not been sorted as it still blows.

The question is, has anyone come across a common issue wit this circuit. I find it very hard to find any articles on it. The wiring diagram is attached. Any thoughts would be much appreciated. I am not 100% with electrical terms, almost need a car electrics for dummies book.

I had help from Lees father Trevor for a bit yesterday and I had already pulled the dash apart tracing wires. We disconnected the mirror motors, fuse blew.
We disconnected the heater motor, fuse blew.
We reconnected the lot hoping it might have been a connection.. nope fuse blew.


Any help and any pointers appreciated.

@t-tony you ever come across this before ?

Hi Paul, only just seen this as I'm only just having my lunch break. I would have a look inside the door cards first as that's where you were working at first. If the fan uses a different fuse I would unplug the fan switch or motor.

Tony.

 

[Brian4]

Hi Paul

Looking at the wiring diagram F24 supplies power to the heater relay to pull the contact in to allow supply to The Heater fan via fuse 20 (30A). So it could be a short in the heater relay which I think is the purple relay,

I would check there are no shorted/damaged wires in the door then disconnect all and pull relay and see if the mirrors work, if so would look like the heater relay.

 

[Brian H]

The screw in the top of the handle holding the door card in place is awfully close to the loom that supplies the mirror switch, on my last car the screw shorted the live wire to the chassis and blew the fuse, maybe worth looking at?

 

[andyglym]

The screw in the top of the handle holding the door card in place is awfully close to the loom that supplies the mirror switch, on my last car the screw shorted the live wire to the chassis and blew the fuse, maybe worth looking at?

Interesting to know, thanks

 

[pgunter]

Well had a very interesting morning with Kirk Wooley who is a local BMW Electrician. We started taking everything apart and took everything off the circuit and I mean everything. Then back on one by one. We managed to find that the electric passenger door window mech had been eating the cable .. and from the photo you will see it has had a nice snack. The issue would have only got worse.

Therefore as a warning to all, I would pay a great deal of attention to the routing of the mirror wires in the doors. It is not just a case of placing them behind the door car. They need to be tucked up away from the moving part of the window mech.

All back together and fingers crossed its solved the issue. A replacement was in my stores, lucky for me. I will have to order another one just incase this happens again.

So to recap.

If your heater fan fails to start and you are lost for what the issue might be. It could be the wires in the door feeding the electric mirrors. This circuit also supplies power to the heated washer jets.

Fuse 20 and 24. It was 24 that kept going. and a 10A for all that load.

As can be seen in the photo below, the outer wire has been stripped and the window was starting on the second course of the inner wires.

 

[t-tony]

Cheers for that Paul. More good info!

Tony.