While following the Mercedes service CD I came to a step that told me to check the voltage between pins 4 and 5 on the diagnosis socket. It said that I should have 0 voltage, but I am reading 12 volts.It said to switch off the ignition immediately if there is voltage there. My question is, could a bad ignition switch cause damage to another component like the controller and result in the engine having no spark?I can't find any info on how to check the separate components like the controller or the crankshaft position sensor and I don't want to replace anything if a bad ignition switch is just going to burn something out again.Thanks for any help. PS the car is a 1984 380SL.

 

Yes and no, if it there is a short and the electricity loops back into some other system like the started motor, yes. But the ignition is pretty much isolated from the other systems with large amp fuses. So No in that respect.

I think the reason you can't find any information on the components you mention is, your car is kinda old for that high tech stuff. Also what controller are you thinking of? Or your Mecedes CD is incomplete? Is it an eBay CD by chance?

 

C280 Wizard, Thanks for replying,in answer to your questions what I called the "controller" is called the "switching unit" in the manual,it has a thick green wire going to the distributor. Second, yes it is an E-bay CD. The actual problem is that there no spark at the distributor and I've been told that the TDC sensor (or crankshaft position sensor) and/or the switching unit could cause this but I don't want to change either if a voltage spike is going to burn them out again, and yes I've checked the coil wire and the coil seems to be good.Thanks again for your help!