GLOW PLUG ANALYSIS

[d9d]

yah, let us know the result, for sure !

I'd be real curious.

I don't think they there's much resistance change until the temp starts getting up there...hundreds of degrees.

In any case, I don't see how any change would mitigate against using an ohmmeter anyway. If the change between -30 and +80 is from 1 to 2 ohms, then the test-spec is "should be between 1 and 2 ohms". That certainly ain't any less precise than a test-light! [img]/ubbthreads/images/graemlins/grin.gif[/img]

When I advise people on GP testing, I refer to a regular DMM, cuz that's all that 99.5% of people have; but I'll fess up that I don't test 'em that way myself much.

I do it with a DC clamp-on current meter. That helps pinpoint the internally shorted ones, i.e. the ones that test good with a light but don't actually heat; because a shorted one will draw different current than the other 7 good ones; and won't have any time-constant, i.e. no change in current over time, as a good plug has.

[welder79]

Nothing underthe hood other than the vacuum buzzer was damaged!!!! The problem I am having is the after glow cycle of the plugs. What determines or tells the relay when to open and close, heat and not heat, the plugs??? Control unit was replaced 6 months ago so it should not be bad. Could the relay on the control unit be causing my problem??? Gotta be something simple because within 6 months the control unit was replaced new total unit relay and all, the glow plug harness was replaced and all glow plugs were replaced with berus. I am about to go crazy chasing this problem. It seems after all I have replaced the truck would fire up no problem but its just not happening.... [img]/ubbthreads/images/graemlins/confused.gif[/img]

[NITROUSN]

the controller measures the resistance through the glow plugs. so basicly the gps change resistance from cold to hot. when they are cold the controller reads that and keeps them on accordingly. when they are hot the controller reads the resistance and cycles them less. when you have 3 or more glow plugs bad on a cold motor the controller thinks the motor is hot due to less resistance and it wont hold them on.

[aaklingler]

Do you start to crank as soon as the light goes off and hold the go pedal down half way while cranking, if so, how how does it take to fire, if not, try it?