Low voltmeter, hard start, then burning smell.

I appreciate the in depth explanation, I'm a complete novice to everything electrical so this is all new to me.

I just went out and tried to test it at the sensor. The yellow wire at the sensor has a little crack woth exposed wire so I just took it from there and then a nearby ground.

So...the reading doesn't seem right based on the chart. I was getting 1380...but to be fair I had also run the glow plugs right before that when I was messing around trying to find symptoms, while doing this I accidently stumbled upon something pretty strange.....

Whenever I went and took a measurement at the sensor wire, and grounded it, the relay opened again. Could it be something as simple as the the connector not being grounded properly? But why would this happen when I ground from the yellow wire and not the black ground?

Edit: to clarify I was able to put the red multimeter end into the yellow wire at the connector and manually force the relay open and close while the key was in run and actively heating the gp's

Twigiestdrip said:

The yellow wire at the sensor has a little crack woth exposed wire so

Click to expand...

So, replace the wire before you chase your tail any farther.

SOLVED:

Well, it appears that old sensor connector was not giving a proper ground, or at the very least grounding intermittently. New sensor and connector and everything working as designed. Relay not staying on and GP's are not always going through a heating cycle after engine is already warm.

Thanks all for the assistance.

Always good to hear about solving a problem. One day, soon after getting my M1009, I was lamenting to my wife," I just want it to work!", she said, "well, you did want something to work on". Good job. Thanks for posting the fix.