cheap300

I've had my 300 for over a year but just started having problems last week. Found this sight yesterday, but was busy all day. I have a couple things you guys should be able to help me resolve.
First: I hope I'm in the right spot. I had a guy at a parts store tell me the 300D and 300SD are the same car, yet I don't see it listed under the S-126 on the front page. The Haynes manual lists it as a 123. So, I came here as I did not see a 123 forum.
Second: Can anyone help me with IDing the fuse box. I have the orginal manual that came with the car, but neither it nor the Haynes manual list the specifics for which fuses protect what.
Third: My preglow indicator quit working and it appears the glow plugs are not heating up as it is almost impossible to crank the car on a cold morning.
Is there a fuse that protects the preglow relay timer or has the relay gone out? I do not see any blown fuses, but plan to replace them all after work today per another thread I read.
Fourth: If I do have to replace the Relay, should I replace the glow plugs as well?
Thank you for help clarifying these matters and I apologize this is so long.

UStifosi

I can only answer #1. The 300D and 300SD are different cars. I learned to drive on a '82 300D Turbodiesel. I remember it being referred to as a 123 also.

VonDeutchMB

I have an 83 300d.

Great car.

Ok first it is a w123. You probably need a Glow Plug relay. If you check the part number on it I might have a spare. Your car has the glow plugs in parallel not a series circut like the older ones (80 and prior) check your fuses (all of them) to see if any are burned out. If you have any questions let me know (I am not the end all be all of 123 people but have done alot with this body style)

Adam

cheap300

Thanks for the replies. Found it is an SD. Also, I replaced all of the fuses in the box. None appeared to burned out and all showed continuity with a voltmeter. However, once all the new fuses were in place amazing things happened. Hi-beams came back (after changing out 4 pairs of headlights), A/C and heater now work, dash board lights came back, but no glow plugs. After digging around somemore I found an 80 amp fuse in the relay that was brittle. Fell into about 4 parts when I pulled it out to replace it. Still no glow plugs. Bought a new set of plugs today and will try that. If still nothing and the parts interchange, I'll get you the part number to see if your spare relay will work. Again, Thanks guys.