Help: Electrical Problem
 

I went to pick up a nice used 300sd. The previous owner has messed up the wiring. I think it has been overloaded. Anyway, the engine will turnover easy but it takes forever to start and it is a rough start. The car has an inside alarm that comes on when the key is plugged in. When the alarm goes off the glow plug light comes on and stays on. I think he said he tried to start it while it was plugged into an A/C car charger. It started and I am happy with the way it ran once up to operating temp. Though a valve adjustment is due, it's loud. I digress, where is the best place to begin my electrical fixing.

I replaced all the fuses. The radio does not turn on, the dash lights and headlights work.

Thanks:)

Nevermind. I just read http://dieselgiant.com/glowplugrepair.htm but it is wierd the light still comes on.