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testing glow plugs

suppose I could do a search, but's been awhile and this is so much more personal,

so my question, when testing the glow plugs, attach the test light to the positive terminal?
 

Fellro

Moderator
Staff member
Yes, that way you can check for continuity through the glow plug. It gives the test light a ground.
 
thanks for the confirmation Fellro. I did do an internet search last night, too. I haven't been pulling the wires off when I checked the plugs recently, would that give a false reading? When I don't plug the old girl in, she starts real hard. Gonna pull the air filter off tomorrow, and check the plugs the right way.
 

Fellro

Moderator
Staff member
Yes, because the light can ground through any of the glow plugs in the harness. You have to unplug to isolate the one you are testing.
 

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