One For The Auto-Electricians

[DJT]

I was under the Stag this afternoon doing an oil change. Had a scan around for anything untoward and noticed that the small White-Orange wire was disconnected from the starter motor. According to the wiring diagram this wire connects to the coil (Mk2 style wiring with no external ballast resistor).

I have not noticed any problems lately: the car starts first time, and goes well. I have done about 400 miles in the past week. What should this wire do? Why doesn't it seem to matter whether or not it is connected? I am fairly certain I didn't dislodge it whilst draining the oil...........

Dave.

[KOY 23]

Hi Dave.It bypasses the ballast resistor to put full battery voltage on the coil when starting. It will help starting in very cold weather when oil drag and battery voltage is down.

[norstag]

Hi Dave
The orange/white wire allows 12volts to go to a 6volt coil to ensure a fat spark when the starter is cranking the engine, with it disconnected you are still getting the lower voltage(about 6v) to the coil which in the present warm weather would not cause a problem, but on a frosty day you would struggle to start, so reconnect it and all should be fine.
Alan

[DJT]

Thanks guys. That makes sense. Good job I found it before the frosts arrive. I think I'll make sure that the lucar connector is a bit tighter so it doesn't drop off again.

TPOTF

Dave