need glow plug help

jimaire · **Posted:** Tue Mar 16, 2010 8:58 pm

Glow plugs don't work. Tested the voltage at the connector and had none. I have 12 volts at the relay on the left fender well, so is the relay(or is it a controller) bad? If it is where can I buy one. Dealer said no dealers had one in stock.
Thanks for helping out.

ATXKJ · **Posted:** Tue Mar 16, 2010 9:57 pm

The voltage at the connector should only be there when the computer tells the plugs to turn on - i.e. starting an air/coolant below 70F.

you can check the plugs themselves - measure resistance of the glow plugs
i.e. trace a wire from a plug up to where it's a 4:1 connector - pull that and measure each wire to ground - if the plugs are good ~.5 to 1.5 ohms - bad is typically 50+

not real sure how to test the GP module - but it was ~$30 from Mopar Parts America.

jimaire · **Posted:** Mon Mar 22, 2010 10:03 pm

I tested the glow plugs and they all showed 0 ohms to ground. I am getting voltage to the connector. Are the glow plugs all bad? The temp was in the 50's when I checked them.

ATXKJ · **Posted:** Mon Mar 22, 2010 10:39 pm

Check your multimeter settings - the 0.5 to 1 is very low - lots of meters have problems reading that and will round to 0.

all of the bad one's I had to deal with - had high resistance not low.

a true 0 reading indicates a direct short to ground - which would mean you're bypassing the plug completely.

Joe Romas · **Posted:** Tue Mar 23, 2010 7:33 am

X2 on what ATXKJ says :mrgreen:

When glow plugs go bad the resistance always goes up. I've owned many VW diesels and have never seen one short. Bad/weak ones always show a highter then specified resistance. And you need a decent digital meter on the lowest resistance setting.

need glow plug help

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