Fig. 1: Using an ohmmeter to test glow plugs — if
the reading is greater than 1 ohm, replace the glow plug
Disconnect the leads from each glow plug. Connect one lead of an ohmmeter
to the glow plug terminal and the other lead to a good ground. Set the ohmmeter
on the X1 scale.
If the ohmmeter indicates less than 1, the problem is not with the glow
plug. If the ohmmeter indicates greater than 1, replace the glow plug and
retest.
