ENGINE GLOW PLUGS 5.5 Testing the Glow Plugs Before performing any test on the glow plugs, disconnect the ground wire from the battery. TEST 1: GLOW PLUGS. With the ignition switch off, connect one end of the ohm- meter lead to the manifold heater terminal and the other lead end to a clean ground. A reading of 1.5 ohms is normal. An infinite or 0 reading means the heater is defective. TEST 2: IGNITION SWITCH to GLOW PLUGS. Remove the 3 screws retaining the right hand dash panel to the dash pod. (fig. C3580, C3581) With the ignition switch off, disconnect the red / white wire from ignition terminal 19.
Connect one ohmmeter lead to the terminal marked 19 on the ignition switch and the other lead to the red / white wire. Low to 0 reading means good continuity. High reading means the red / white wire from the ignition switch to the manifold heater is defective. TEST 3 IGNITION SWITCH “HEAT” POSITION. Connect the ohmmeter leads between the terminals marked 30 and 19 on the ignition switch. (fig. C300) Turn the ignition switch to the “HEAT” position and observe the ohmmeter readings. Low resistance reading normal. High resistance reading, replace the ignition switch.
Glow plug location C2053 Ignition switch Mounting screws 5 C3580 Pre-Heat Indicator Check the ignition switch terminals 17 and 19 with an ohmmeter. If there is good continuity between the two terminals the bulb or wiring is bad on the pre-heat indi- cator light. To change the indicator bulb, remove the 3 screws retain- ing the left hand dash panel to the dash pod. Select the proper bulb, twist and pull the bulb from the dash panel. Disconnect the wires and replace the bulb in reverse order. C3581 C300 5-13