Electrical Problem

[Avyer]

I have a 1986 560SEL that won't start or well do anything at that. I was wondering if there is a relay that is between the battery and the electrical system... Or what else could it be... I have tried jump starting it and that did not work either.

[porkface]

the only things electrical between the battery and the starter are the ignition sw and the neutral safety sw. does the car crank? if not, what is the voltage at the battery? how about while cranking? move the shifter back and forth while cranking, in case the neutral safety mis the problem. might be out of adjustment or the shifter bushings are loose. if the voltage at the battery is ok, you can bypass things with a factory connector. on the false firewall, next to the brake master is a 3 pin connector with a purple wire in the middle position. this is the starter feed from the ign sw. i forget which half to use but, apply 12v to the purple wire and the starter should spin, if that's not the problem. if you use the wrong half, nothing will happen, good or bad. if for some reason later, you want to run the fuel pump, unplug this same connection with the key on and the pumps will run. just plug it back in before you close the hood. if you can't spin the starter this way, the the ground on the engine is loose or broken or the starter is dead. good luck, chuck.