My 1991 318i had a push start button which I am now removing. From the moment I bought the car, it had never started via the key. Procedure was to turn the key to the On position (2 clicks), and press the push start button.
I have now found that I can start the engine by following this procedure:
1. Turn the key to the On position (2 clicks).
2. Short the following wires: Black and Green/Gray.
Photo of the wires:
I want to make it so that I can start the engine via the key, without shorting the wires by hand.
I tested the "output" of the key in various positions, but I can't figure out why the ignition key is behaving the way it behaves:
- Black and Green/Gray are already connected when the key is in the On position (but the starter motor does not engage).
- The main between On and Start positions is that all electrical connections to the Green/Gray wire seem to be cut in Start.
- Other differences are slightly lower resistance on the Red-to-Purple and Green-to-Purple wires.
I notice that the key needs to be turned back to Off before it can be pushed into Start again. Not sure if this is the normal behavior.
I found a couple of threads here saying the plastic part with the terminals/wires could be worn out inside - but I don't understand why the car starts when I short the Black and Green/Gray wires, when they are already connected in the On position. Should I be checking voltages too?
Attached some tables showing the electrical connection between wires/terminals and between terminal to ground.
Thanks in advance
TJ
