oliver28472
Veteran Member
Here's a more detailed answer. Different brand but the same applies here. Found this in a search, thanks to Jinman.
With power off, remove the busbar connection to the glowplugs. Measure the resistance from the busbar terminal of each glowplug to ground. Make sure it's a clean surface and that the meter is making good contact. Your glowplug should read approximately 1 ohm to ground. You may read as high as 1.5 ohms due to change with age, but not much more. If the glowplug is open (infinite ohms) then it is bad. If it is zero ohms (shorted) it is also bad, but most likely if bad, it will be open. If it is shorted, it will normally blow a fuse because it will draw too much current.
If you are using an analog ohmeter, you need to set it on the lowest scale and zero it very carefully before making this reading. If it's a digital meter, you probably have no way of zeroing the scale.
With power off, remove the busbar connection to the glowplugs. Measure the resistance from the busbar terminal of each glowplug to ground. Make sure it's a clean surface and that the meter is making good contact. Your glowplug should read approximately 1 ohm to ground. You may read as high as 1.5 ohms due to change with age, but not much more. If the glowplug is open (infinite ohms) then it is bad. If it is zero ohms (shorted) it is also bad, but most likely if bad, it will be open. If it is shorted, it will normally blow a fuse because it will draw too much current.
If you are using an analog ohmeter, you need to set it on the lowest scale and zero it very carefully before making this reading. If it's a digital meter, you probably have no way of zeroing the scale.