|
Do you have any of the various service manuals? There is no Haynes Manual for the W115 300D, but there is one for the next series, the W123. The early W123 300Ds use the same basic engine as the W115, with slight variations, so there is some relevant info there.
There are also a couple of Chilton manuals out there, not to mention the Mercedes service manual, and a few manuals on CD.
You can find guidance for testing glow plugs, etc. there, and it can save you a lot of time and.... Aggravation. I tested my GPs years ago, so I can't recall the readings. I know that I tested them in the block, in sequence with a meter. The meter readings basically decline about a volt at each GP... Down to 1 or two volts by #5, if memory serves. If one is out, no power reaches any GP after that in the series. You can also visually see the two little grid connectors turning bright red as they heat up.... So you know if you are getting power there.
You can get the correct meter readings from someone more familiar in here, perhaps, or from the manuals.... Or you may even find it written up online somewhere. Wish I could be of more help, good luck.
|