Starter only just turning and brown/orange burning out

[nightroamer]

Gents,

My 320i has been fine all morning, started a few times with no effort.
Now the starter suddenly seems like it has bugger all power. Turns over once slowly then stops, battery is new and fine.
Also when cranking there was some smoke from a brown/orange wire in the loom coming out of the bulkhead near the battery.

Any idea what the brown/orange wire is? think its the wrong color for solenoid.

tried giving the motor a tap, no affect.

thanks

[ian332isport]

Brown/orange wire will be an earth.

Sounds to me like the engine earth strap has broken and the starter motor is trying to ground itself through other earth wires.

Ian.

[daimlerman]

Brown/orange wire will be an earth.

Sounds to me like the engine earth strap has broken and the starter motor is trying to ground itself through other earth wires.

Ian.

Brown with a tracer is an earth going via something,oil pressure switch?
Agree with failed engine earth,or just a rusty chassis leg....

[nightroamer]

checked engine earth strap is all good.
could be the oil pressure switch, why would it be cooking though?

[nightroamer]

thanks guys, problem solved, well sort of, its the engine earth. But the earth cable is fine to the sump! wierd, may add a second strap.

[daimlerman]

Earth straps are funny things,a nice shiny new one is cheap to buy and can fix all sorts of starting/running problems.

[Brianmoooore]

Doesn't need a second strap - just the one you have cleaned up and refitting.
The brown/orange wire that's burning is the earth connection for the oil level sensor, which (bad design) also connects to the aluminium body of the sensor. If the earth strap fails, the starter current follows this parallel path.

[nightroamer]

Doesn't need a second strap - just the one you have cleaned up and refitting.
The brown/orange wire that's burning is the earth connection for the oil level sensor, which (bad design) also connects to the aluminium body of the sensor. If the earth strap fails, the starter current follows this parallel path.

thanks Brianmoooore, that appears to be whats happened.
any idea where the cable goes inside the cabin, i better remove and replace it.
Where is good for earth straps??

[DanThe]

Best to cut it near the engine somewhere and earth it to the engine block, you wont have any burning if the earth strap goes again

[Brianmoooore]

The burnt wire is confined to the engine loom, and eventually connects to earth on the top of the RH suspension turret.