All electrical gone!
 

Started the 1978 300 CD this morning, and a couple of seconds later, all of the electrical went dead. Motor was still running, but no lights, radio, nothing. Turned it off, and tried to restart, but it was as if the battery had been removed. This is the same vehicle that I have posted about recently where the high beams blew, and the heater blower fuse kept melting. We have tried to clean as many contacts as possible, but obviously there is some other gremlin we have missed. HELP!

You need to look at the electrical ' tree'....and
start cleaning on the GROUND side... starting at the negative battery terminal... and taking all wires off and cleaning with brass brush or something like that...
ALSO.. cut the wire insulation at the ends of the battery wires to see if corrosion has attacked them..
faulty grounds cause excessive current draw and can cause this type of thing..

But also check to see if you have a broken battery post...

As above, and also, ground paths can check ok when checked by a meter, but still fail under load.

I had lots of heartache and angst with my 250C that had a bad ground cable from the battery to the chassis ground, checked out ok with an ohm check, but failed under load.

Jim

x3 on many gremlins bad grounds are the problem.