86 f250 6.9 diesel. using a brand new 12v test light to test brand new glow plugs (pos to bat , neg to plug term.) not a one lighting? if i ground neg test light to grnd. motor, etc. lite is on. could i be...
You are doing it wrong probably.
If you want to test current to the glowplug, remove the wire and test between it and ground.
If you want to test the glowplug itself, then use an ohmmeter. That is because you don't know what the resistance should be in comparison with the test light, and it sounded like you were testing it in parallel. If the glowplug drew a lot of current, which it probably does, then it would **** so much current way from the testlight, that it would not light up. In general, bad glowplug either go to 0 or infinite resistance, but an ohmmeter will still be more accurate. A test light can be used, but you need to put it in series, not parallel as you would with a light bulb.
Mar 19, 2010 |
1986 Ford F 250