PeachParts Mercedes-Benz Forum - View Single Post - Well my 240D glow plugs failed this morning

pj67coll · #36 02-23-2015, 08:14 PM

Ok. So trying to troubleshoot everything systematically. I first tried reading the voltage at each glowplug by the method. Black probe to ground (by fuel filter), Red probe to the glowplug itself with the key in position II. ie the glow cycle should be operating. No sign of a glowplug light in the dash but my readings, starting from front of the engine towards the back assuming the front is #1.
11,43V 11,36V, 11,37V and 11,36V.

Each time I held the probes in position till the relay clicked off and the voltage on the meter went to 0V.

I wanted to re-check these results before moving on to testing Ohms etc but before I could do that the damn black cable on the meter good hooked on something and pulled out of the probe.

I printed out another coupon, started the car - started immediately but real rough so increased Idle knob to max for about 30 sec's. Went to HF and got another free tester. Second round of testing Voltage at the glow plugs themselves with the new tester.

11,73V 11,6V 11,6V and 11,5V.

Again meter went to 0V at each plug when the relay klicked off.

Wifes' just come back with the dinner so I gotta go. I'll try to do the Ohm testing later this evening if I can get to it. But from these figures it seems that I'm getting good voltage at the plugs am I not?

- Peter.