On my 84 6.9 f350 the glow plugs are all in ok shape, and the relay reads 12v but doesn't click like most say it should. I know it might also be the controller, however I'm wondering if maybe the relay reading 12v but not clicking could be the issue. Any advice? Should I just replace the whole system and go from there?
Hi there. Based on your input, it’s likely that the source of your issue are the relay’s (as indeed they do "click" when activated) but it’s also possible that your issue is caused by a different ignition system component. Assuming you’re getting fuel, it’s possible that the distributor or rotor is causing the ignition timing to be off; which would create a no-start issue. If you’re going to complete these repairs yourself, I would recommend starting with the easy stuff first; check your distributor cap, rotor for damage. If this is good, move onto the coil; then if all check out fine, replace the relays; as the vehicle being over 30 years old is likely due to have a major electrical overhaul.
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