QuestionQUESTION: I JUST REPLACE THE GLOW PLUG RELAY WIRING HARNESS AND GLOW PLUGS WHEN I GO TO START THE WAIT TO START LIGHT FLASHES AND THE RELAY CLICKS FOR ABOUT 10-20 SECONDS WHY. NEXT QUESTION IS THAT I HAVE A LEAK ON MY WATER/FUEL SEPARATOR JUST REPLACED FILTER AND DRAIN NOZZLE AND GASKET ON BOTTOM. I AM NOT SURE IF IT IS LEAKING ON THE BOTTOM OF THE FILTER OR THE TOP THERE IS DIESEL ON TOP AS WELL NEST TO MY CONNECTOR . I HAVE A 1990 F350 7.3 NON TURBO
ANSWER: did you ck for any codes if so what are they we have been having problems with the controller but you need to see if you have any codes first
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QUESTION: no did not have a check engine light on
Answer1. At the glow plug controller, verify the Dark Blue (DB) shows battery voltage with the key on. Also make sure the Black/Orange (BK/O) wires maintain battery voltage when turning the key on.
2. If the power feeds in are good, verify the ground to the housing of the glow plug controller is good.
3. If the powers and ground are good, but there is no or low voltage out to the glow plugs when turning the key on, even when the Wait to Start light is on, replace the glow plug controller 1. Start with checking the resistance of the glow plugs even if they are new. When cold, the glow plugs should read about 0.5 ohms each. If they are more than 1.0 ohm when cold, they are incorrect or defective.
2. If the glow plugs show the correct resistance, check for any voltage drop between the glow plug controller and the glow plugs when the glow plugs are commanded on. If there is any voltage drop measured, repair the wiring as needed and retest.
3. If all wiring and the glow plugs check OK, suspect a faulty glow plug controller.
