Engine to normal temp and running .. why do glow plugs cycle?

[G. Mann]

Need some help on this one please.

Drove the 92 F-450, 7.3 across town this afternoon [about 10 miles in rush hour traffic so I know it was up to temperature..] Pulled into the drive and noticed the amp gage was reading low and pulsing like it does when glow plugs cycle.

Turned key off, engine off, immediately tried a restart, and the glow plugs cycled, engine temp was setting in the normal position.. about 4 needle widths above cold. That's where it always runs.

Question: Why are the glow plugs cycling while engine is up to temperature and running.. ?

Something isn't right.. what?

 

[chris142]

Mine did that.found a loose wire on the controller.

 

[LCAM-01XA]

Check the red wire powering the controller, and the black one that grounds it to the intake. Loose power wire will make it think you just turned the ignition on every time it makes decent contact, loose ground wire on the other hand will cause it to go stupid and hold your plugs on for longer than needed potentially burning them out.

 

[G. Mann]

Thanks guys !

I'll be checking the connections today to see if that's the issue.

Anybody else have experience with this?