just purchased 1983 300SD 2 months ago and have put 5000 miles on it!-- love the ride.
On a long trip last week, my glow plug indicator light stopped working. Normally, the glow plug indicator light would come on about 10 seconds then turn off.

I sell Mack Trucks and have a shop that is familiar with diesel engines (since that is all we sell). I was wondering how the glow plug system works and if somebody has advice on how to diagnose what particular portion is at fault. (tested the glow plugs with meter and seem to be working fine).

If anyone has schematic, that would really help, too.

thanks--rob

 

Hi Rob,

Congratulation on your purchase. I owned the same car up to three years ago. These cars are GREAT. Most reliable car I ever had.

You don't really need a schematic, but read my reply to a similar problem in the post titled "85 300D", dated 2/9/2005 in this Diesel Forum. You will find the relevant glow-plug troubleshooting information there.


Phil

 

Thanks for the information. I printed your responses and will try to tackle the problem when I get back from vacation. Although the glow plug light does not come on, the car starts fine even on a cold morning like today (28 degrees).

Thanks for your time in answering my questions and I will start by going through your diagnostic scheme. If i have any more question, I look forward from hearing from you!!

Rob

 

I had a similar problem. When I replaced the #1 glowplug closest to the fan, the light started working. Also consider that maybe the bulb burned out. Easest to push dash cluster out from the back if you don't have the dash removal tools. (bent coat hangers!)