Glow plug controller problem?

[quickster45]

Went out this am to check for loose wires and such, being the plugs are being cycled long after starting. Started it up, and it cycled(volt gage needle back and forth), for about 10 seconds, and then off. That's the way it is normally. It's running at high idle because it's cold--didn't have to plug it in becase it's 50F here in Jersey. Soon as it comes off high idle, it starts with the needle bouncing back and forth on the volt gage. What the hell? Once it's warm, somethings telling it to cycle? Or could it be something totally unrelated to glow plugs? Any help here would be mucho appreciated.
__________________91 f350 7.3

 

[cleithau]

Should just be the controller. Someone else will know more, I fixed mine by eliminating it and manually controlling the glow plugs. Its way simpler and it will outlast the controller by years. And it starts better in cold weather.

 

[quickster45]

Have any diagrams or pics on that? Or maybe just change the relay?

 

[cleithau]

It said 87-94 on the caption when I saved it to my comp. Should be right.

 

[quickster45]

thanks for the info. Now I'm thinking something else might be doing it. Will do a new post