I have a 1983 300SD Mercedes Benz that won't start. Occasionally over the past month when i would try to start the car it wouldn't turn over at all (there was no response) for about 15-30 min. then it would start and run normally. Now it wont start at all, but it attempts to turn over. We thought it may be the battery and tried to jump start the car, but it had no effect. Any ideas?

check to make sure it is getting fuel and make sure the vaccume kill valve is not stuck in the kill position
even if the glo plugs are dead a small shot of either should help it start and it should run on its own

THIS HAPPEN TO ME THIS WEEKEND. CAR WAS STARTING AND RUNNING GOOD . MONDAY NO START SEE IF YOUR PREGLOW LIHGT IS GOING ON .RIGHT HAND SIDE OF DASH ABOVE THE KEY LOOKS LIKE A CURLEY WIRE. IF NOT GO UNDER HOOD LOOKING AT THE CAR RIGHT HAND SIDE RECTANGULAR BOX IN FRONT TOWARDS YOU POP OFF LOOK INSIDE AT TOP SMALL FUSEABLE LINK (band of metal) REPLACE IT IT WORKED FOR ME TOTAL COST $3.61 AT AUTO PARTS STORE GOOD LUCK