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Old 08-01-2011, 10:50 AM
tangofox007 tangofox007 is offline
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Join Date: Sep 2004
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Quote:
Originally Posted by markg612 View Post
The relay has some minor intelligence and it senses resistance and current draw if I remember correctly in each plug among other things. During acceleration, the plug will heat up from the energy of combustion and increase the resistance measurement. The sensing circuitry may be returning a "false positive"of plug condition or actually detecting a fault in one of the plugs.
The fault detection function should not be measuring anything once the preglow sequence has been completed. Also, the lamp indicates a fault by not illuminating.

Quote:
Originally Posted by MB300D81 View Post
Ok, After giving it a good tests. I found that I was running on only two good glow plugs out of the six.

No wonder the relay was showing the GP light on the dash.
Why was the relay "showing the GP light on the dash?"
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