PDA

View Full Version : Bosch Starter Motor Diagram - Mk3 Golf



alexmcc
02-06-2007, 10:04 PM
Hi there. Wondering if anyone has a diagram of the starter motor for the mk3 golf. Haven't got access to a Haynes or Bentleys manual. Just trying to troubleshoot my starter and just want to know what each part of it is called. Thanks very much.

Flash2
02-06-2007, 10:28 PM
Hey Alex, I just read your other post about the popping sound and smoke.
Here is what to try : Look at the wires going onto your starter motor. You'll see a big heavy red wire (leading to the battery positive terminal) and a thinner black (with red tracer) wire. Disconnect the black wire from the starter. Now check your car is out of gear and the hand brake is on. Find yourself a length of wire and hold it onto the terminal on the starter where the black wire was connected. Now touch the other end to the battery positive terminal and see if the engine will crank. If it does, then the starter motor is OK and the problem is between the ignition switch and the starter. If you get a little spark when you touch the wire onto the battery, then the problem is probably within the starter.

Another thing that could cause the same problem is a high resistance on the engine earth strap. To check if that's the problem get a set of jump leads and connect one black clip to the battery negative terminal and the other black clip to a bolt on the engine somewhere (leave the red clips disconnected). Now try starting the engine. If it starts now it's the engine earth that's the problem.

Hope that helps - Jim.

alexmcc
03-06-2007, 11:39 AM
I've taken out the starter motor and had a good look at it and the solenoid. The brushes etc seem fine but what I have noticed is a thick copper like wire. Its not really a long wire but it goes from the solenoid to the starter. This has split and no longer makes a connection between the two. Its pretty obvious to me that this could very well be the problem and must be a vital part to the starting system otherwise it would not be there. The problem i have is that I cant for the life of me figure out what this is for. Could this be an earth wire or is power running through this wire to the starter. Can't get any good diagrams on the net and dont have a Haynes manual. Help please!!!

Flash2
03-06-2007, 01:11 PM
Alex, that wire carries the current from the battery (via the solenoid contacts) to the brushes inside the starter. I think you'll have to replace the starter motor as repairing that wire can be a bit tricky. Have a look in the yellow pages for a local auto electrician who should be able to supply you a reconditioned unit at a reasonable price.

Regards - Jim.