Possibly 1 or more. They each are getting voltage. I noticed widely different voltages at the plugs. (11.1 - 11.9v)If I know battery voltage and the voltage at each glow plug, I can calculate current by the voltage drop. Well, no.... I don't know the resistance. If I remove the wire and measure, can the resistance of the plug to ground be an indication of good or bad plugs? I could measure the current of each if I can get my curent probe around the wire. The probe is pretty big.

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Michael LaFleur

'05 E320 CDI - 86,000 miles
'86 300SDL - 360,000 miles
'85 300SD - 150,000 miles (sold)
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'98 ML320 - 270,000 miles (sold)
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