Glow Plug Control Unit
- Turn off ignition switch and unplug glow plug control unit. Unit is located in right side cowl area of passenger compartment. To test control unit, wiring harness must be constructed. See Fig 1 .
- To test indicator lamp circuit, voltage source must be 10.5 volts. Close switch No. 1 and measure the time lamp "A" is lit with various resistance readings. See Indicator Lamp Circuit Test table.INDICATOR LAMP CIRCUIT TEST
Resistance: Ohms Illumination Time: Seconds 19,000 5-7 11,500 4.5-6.3 5600 3.5-5.1 3700 2.9-4.3 1200 .6-1.9 - To test pre-glow circuit, voltage source must be 10.5 volts. With switch No. 1 closed and switch No. 2 open, set resistor to 30,000 ohms. Lamp "B" should be lit for 5.3-6.7 seconds. Close switch No. 2 and set resistor to 20,000 ohms. Lamp "B" should be lit for 5.5-7.5 seconds.
- To test after-glow system, voltage source must be 12 volts. Switch No. 1 must be closed. Close switch No. 2 and then open it. Measure time lamp "C" is lit with various resistances. See After-Glow Circuit Test table. Replace control unit if it fails any test.
AFTER-GLOW CIRCUIT TEST
| Resistance: Ohms | Illumination Time (Seconds) |
|---|---|
| 19,000 | 38-55 |
| 11,500 | 33-49 |
| 5600 | 25-39 |
| 3700 | 20-31 |
| 1200 | 15-25 |