GP Controller

[Subzilla]

I've got an old style controller on the '83 that I believe is acting up. Symptoms: When key is turned on, glow plugs light up for the usual 7 seconds or so, then go off, then will continously and quickly flicker. Things checked: per TDP troubleshooting guide, the resistance for the controller checked out per specs. I checked the voltage at pin 3 and got a constant voltage for the first 7 seconds, then flickering voltage after the first cycle. This would indicate a faulty controller?? Why would it act fine on the first cycle, then malfunction on the second cycle?

[Lightyear]

I have a similar situation with my '88 Burb. I have relocated the controller to the fenderwell, and still get the erratic flickering and cycling after start. I am leaning toward a faulty connection from ignition to controller, starter to controller, or a poor ground. I'm trying to track these down with a GM schematic. Will letyou what I find, maybe it will help. Good luck

Buzz

[john8662]

On the '83 setup it could be either the controller or the relay.

My '82 works somewhat normally, sometimes after it's started and doing the "afterglow" the controller will command glow and I'll just see the light in the cab flicker for 1 second, verses the 2 second partial afterglow that would be normal.

Sounds like you get one good glow, but the afterglows are erratic. The relay is cheaper than the controller by a long shot on the 82-84 systems, which is what I'm leaning towards being wrong on this unit. It could be either though... Check connections etc as usual.

On the '88 setup, there is only a controller, so check connections, but it's possible that the relay that's integrated into this controller is failing, because the contacts inside are worn. A failed relay/controller can be associated with a chattering sound.

J

[Lightyear]

John - What connections are the most likely culprits...the run input or the strat input? I have relocated the controller in my '88 to the left fender, added a new pigtail harness, and also added an additional ground to the block. The controller was brand new, about 4 months old by now. I've had this problem off and on since I bought the truck.

Buzz