My truck doesn't see as much road time as it used to due to high fuel prices. As they keep coming down, I am getting the itch (money) to drive it more often. Back around Christmas I took the wife muddin and on the way home I noticed the glow plug light coming on as I was driving down the road. It would come on for a few seconds and go off, then come on again, sometimes for a few seconds and sometimes for a couple of minutes. Now the glow plugs do not come on at all. What have I done. Blow the switch, burn out the plugs, or something else all together. I have been meaning to do a manual overide of the plugs, but have not done it to date. I thought there used to be a sticky, but cannot find it. Please help. What have I done and how do I do the manual switch?
Thanks in advance.

Perhaps the glow plug controller malfunctioned because apparently it sometimes does happen and all eight glow plugs burn out.You can simply buy a universal starter solenoid switch which has two large side terminals,and two smaller terminals.One of the small terminals has a "S" stamped near it while the other small terminal has a "R" for resistor.The resistor side can be left alone.Then its just a matter of powering up the solenoid by taking some wire of the correct gauge(At least 10 gauge)leading from the large right stud and then direct it back to the positive battery terminal while the opposite large stud accepts the wires from the glow plugs and your glow plug wait light.Then run a wire from one side of your push button to the "S" terminal on the solenoid.The other wire coming away from your push button is put upon that large right stud on the solenoid which has its wire headed back to the positive battery terminal.You can mount the solenoid on the firewall.It has a bracket built into it so you can use a couple of small screws or 1/4" bolts to secure it in place.

Each time you press the pushbutton,you'll hear the solenoid make a thumbing noise which means the glow plugs are being energized.When you release the button it'll make the same noise.

I'm pretty sure i've explained this okay,but if i'm incorrect i'm hoping someone will correct me.

Don't forget to put a fuse in there as well to protect yourself.

You can use the factory glow plug solenoid (provided its still functional), all you have to do is remove the ground supply to it that comes from the controller and wire in a push button in its place....quick and painless. Make sure you put the 60G glow plugs in. Good luck.

You can go the manul way if you like, but it might just be that the solder connections on your controller have cracked and are intermittent.

Your symptoms are almost inditencil to mine. I pulled the controller off, took off the bottom plate, and pulled out the pcb board. The connectors come with it, and on mine they were all cracked. Re-soldered them and all worked fine then.

You can go the manul way if you like, but it might just be that the solder connections on your controller have cracked and are intermittent.

Your symptoms are almost inditencil to mine. I pulled the controller off, took off the bottom plate, and pulled out the pcb board. The connectors come with it, and on mine they were all cracked. Re-soldered them and all worked fine then.

Did the same repair to mine. Been working for two years now. I also keep the manual button for the cold weather, the automatic controller works ok but it starts better in the cold with some manual timing of the glow plugs.

84 GMC K2500 6.2L J Found I was only getting only 10v to the solenoid coil. Supplied by the controller on the block. Replaced it. Same problem. Found a part that looks like a diode jumping across the factory plug to the coil of the solenoid. My meter and experience with diodes says it had failed. Cut it out. Works normally now. Anybody know what purpose that part serves when it works? Is there any reason to replace it?

Well, this is a guess but it probably acts as a clamp that keeps the voltage from spiking (too high or low) when the solenoid cycles.