GEAR (50 T.) 7M1383 - Caterpillar

Continuity Check of the Glow Plugs
The following test will check the continuity of the glow plugs.
Disconnect the power supply and the bus bar.
Use a suitable digital multimeter to check continuity (resistance). Turn the audible signal on the digital multimeter ON.
Place one probe on the connection for the glow plug and the other probe to a suitable ground. The digital multimeter should make an audible sound. Replace the glow plug if there is no continuity.
Check the continuity on each the glow plugs. Checking The Operation of The Glow Plug
The following test will check the operation of the glow plugs.
Disconnect the power supply and the bus bar.
Connect the power supply to only one glow plug.
Place a suitable ammeter on the power supply wire.
Connect a suitable digital multimeter to the terminal on the glow plug and to a suitable ground.
Turn the switch to the ON position in order to activate the glow plugs.
Table 1
12 Volt System
Amp Time (sec)
16.6 Initial
12 5.7
9 11.1
7 20
6 60
Table 2
24 Volt System
Amp Time (sec)
9 Initial
7 3.3
6 5.3
3 60
Check the reading on each glow plugs.
If there is no reading on the ammeter check the electrical connections. If the readings on the ammeter are low replace the faulty glow plug. If there is still no reading replace the faulty glow plug.