6.2L glow plug/controller problem part 2

[BIOBEV]

Well today I went out to roll up the windows all the way, storm coming in. I turn on the key to roll up the windows man I hate not having an accessory only place on the ignition always putting juice to the glow plugs to roll up windows. ANYWAY the glow plug light came on, on the dash and low and behold the truck fired right up. Yesterday nothing, like nothing was wrong today. Anybody know what might cause this. Was already to order a controller now I wonder if that is the problem. Any ideas!
Thanks

[More Power]

What year truck is it? Has anyone messed with or modified the glow system?

Jim

[BIOBEV]

It is a 1988 Suburban no modifications .

[john8662]

Could be a couple of things.

The controller could have a bad connection, remove the controller harness connector and re-connect to ensure a new electrical contact. The controller is located on the back of the engine on the driver's side head.

The controller could be faulty itself.

an ignition source is intermittant, perhaps a bad ignition switch (not fun).

J

[NH2112]

Next time you get nothing when you turn the key, check the voltmeter and also turn on accessories that are powered through the ignition switch (turn signals, factory stereo, etc.) It's pretty common for the battery cable to loosen at the starter, which usually gives you intermittent problems when you try to start. There's a wire with a fusible link on the starter's main power stud that goes up to the small diamond-shaped block on the firewall, and from there through the firewall to the ignition switch. Check for loose connections or corrosion on this wire, too.

[john8662]

Just something else to check...

Over the weekend my glow plug controller quit working on my '86 pickup. Well, I did some troubleshooting and found that the ground connection to the controller main connector was very faint. Check your ground on the back of the engine that grounds the engine harness. The ground to block connection can be found on the passenger's side rear. The connection will be on the 2nd to last intake manifold stud, make sure there are two wires there. A strap to chassis wire and a regular ol #16 gauge black ground wire that goes into the harness.

J

[dieselbegreat]

I had similar intermittant problem and decided to bypass the coolant temp sensor (I think yellow/orange wires run to it frontish/center of intake). I tied the two together with a wirenut and haven't had a problem, plus the controller will more likely give good glow when the engine is just luke warm now. It could also be a bad controller (mechanical relays do go bad).

[BIOBEV]

Thanks for all the replies. I wiggled the plugs around and everthing seems to be working for now, probably need to replace controller soon.

[Robyn]

This truck may very well have a glow plug inhibit switch.
If it does it will be located in the top rear of the passenger side cylider head.
The is also a similar switch on that same head down by the exhaust manifold and also in the rear, dont mess with that one as it controls the cold advance and needs to work.
The one on top, if you have it is the inhibit switch and all you need to do is take a 2" long piece of #14 wire and crimp on two male spade connectors and plug these into the plug that is on that inhibit switch. This will stop the glow system problem.
My 86 had this happen on a cold and wet and snowy night I manually jumped my glow relay to get going but was not amussed. The inhibit switch is temp sensative and can work some times and other times not. This item was deleted in later years as it was a pain in the !@#$.
Good luck