Any VW Mechanics here?

[Travelover]

I second Bererman's idea. Starter drops voltage to a point that module does not work. When starter stops drawing the voltage rises and module works. Can you put a voltmeter on the input to the module?

Technically I'm sure the answer is yes. It has a fist full of wires that go into it, so I'd need to figure out which one is the power in. I did find the relay that powers it under the dash, so I might be able to check voltage there.

 

[banjodunn]

G'day don't know that vehicle but can you check the back of the ign switch or at the loom plug for the switch and see if you can work out which is the ign feed wire out of the switch ( test light to see which wire powers up when ign turned to on), and then turn it to the start position it should retain power if not then throw ign switch to the s%^&house and replace.
Another way to to check switch is faulty is to feed power into that ign wire and then crank ( you can do this by backprobing the plug with a jumper wire from the batt).
Good Luck

Jon

 

[orezok]

I would check for rodent damage to wires also.

Sometimes it's a barely visible bite through a wire.