DesmondD

Hi everyone , this is my first post here - I have found much of my information n these forums since getting back into auto electrical a year ago [ after 4 years training as a diesel fuel technician] - so I've decided to register .
I am busy working on a 1994 mercedes C200WDB2020202F077871 .
It came in for running rough and intermittent starting problems .
We told the customer we would have to replace the engine harness before touching anything because it was crumbling.
It has run for a while since replacing the harness but after a few starts today it won't crank any more . There is a purple wire from the ignition switch going out under the fuse box [ Right hand drive , fuse box on right as well] .
On the left of the vehicle in the engine compartment is the ecu with a large harness underneath it .
The starter has a purple wire coming back up into the harness [ I can bridge the starter to make it start ] . That harness also goes under the ecu .
I get no signals at the neutral switch when trying to crank so I imagine my problem can be halved by finding the start relay .
Any ideas where it is please ?

I also have a fault code for leaking map sensor hose but can't find the map sensor - they hide these components pretty well don't they ?

DesmondD

I'm including a screen shot of the "implausible" cam angle sensor pattern for those interested .
Update : I'm told this signal is normal for mercs only - they have a magnet that causes the double trigger.

DesmondD

ok , based on information on a local auto electrical forum a common fault is the central locking module in the boot on the RHS . I opened that up and found dry solder joints which has fixed my problem