Need Help - Glow Plug???
 

I had my 85 MBZ 300SD Turbo left with a friend while I was out of town for over 6 months. It had been used some while I was gone, but not much.

Now that I am back I find that it is very hard to start. The Glow Plug light no longer comes on, so I am thinking that maybe the fuse that powers the glow plug is blown. I was told to listen for the sound of the glow plug switching off after about 30 sec, but nothing can be heard.

Could it just be a fuse? Where are the fuses located and which one is for the Glow Plug?

What else should I look for?

When I say hard to start, I crank for about 10 to 15 sec each time, and it may take from 4 to 8 times before it will finally fire. Once the engine is warm it will fire quickly and easily.

Thank you for your assistance.

On the drivers side inner fender, there is a black rectangular box(glow plug relay) with a lid. Under the lid is a 80amp strip fuse held by two phillips head screws. That fuse is for the glow plugs, and if it fails the light will not come on.

If the fuse is ok, then you may have two or more burned out glow plugs or a bad relay.

I say look for the simple problems first:

1. glow plug relay fuse.(very possible)

then

2. burned out glow plugs(somewhat possible)

then

3. bad glow plug relay(possible, but least possible of the three choices).

The fuse can get a hairline crack that is not easily seen, it's a safe bet to just replace it. They cost around a dollar.

4) Check for fuel leaks (primer pump on side of IP is common).

In sunny San Diego with "reasonable compression" it should not take 8 cranking cycles to fire.

Thanks, I will go check it right now.