I've nearly got my truck running after swapping in a 6.5L engine. I got the engine from a suburban that had gerry rigged glow plug wiring, which I'm now not sure was done correctly. I tried to dublicate the wiring in my truck, after putting in new glow plugs. The relay is sending 12 volts to the plugs, but the plugs aren't heating up. I pulled a plug, hooked up the lead to it, and grounded it to the block. With 12 volts going to the plug, nothing happens -- no heat at all. Then I tested the plug with an Ohm meter, and it reads that it's dead. I expect the other plugs to behave the same way since the truck doesn't want to start cold.


Here's my question: I need to get this truck running soon (today if at all possible). Can I get new plugs and wire them through a switch in the cab and skip the relay entirely? I would simply cycle the plugs myself manually. This would be a temporary fix until I can figure out the relay wiring and get it right. If I can do this, what precautions do I need to take to keep from burning out the plugs again?


Thanks

A momentary switch on the dash and possibly a relay to carry the load of the plugs. The relay is wired to switch with the input of the montary. The common carries the load.


Not all plugs are rated for the same duration of glow. Some heat quicker but burn out faster. know what your getting G 10, 11, 60, 90?Edited by: quantum mechanic

I think the plugs were G 11. The parts store will replace them with the same. How long can they glow?

In another post gmctd says 11's are dual element.


I would think it would be ready in between 5-10 sec depending on how cold the engine was and outside tempatures.

Should be able to just see which plugs are spec for the controller you have by year model of the engine. Momentary switches work, and can help startability, but could still cost you premature plug failure.

I've wired up a momentary switch and a relay that I think is for a starter, so it should carry the load no problem. Tomorrow I will pick up a new set of plugs and then hopefully the truck will start up. I plan to cycle the plugs for about 5 -10 seconds as QM suggests.


Any other suggestions? Any advice on where to find a good diagram for the actual glow plug relay if I ever decide to install it?


Thanks for all the help.

When my relay failed I simply installed a spare Ford Pinto starter relay. Any kind will work. Get one from a junk yard or maybe you have a spare one laying around like I did. If your glow plugs are bad, even one, then replace all of them with Delco 60G's. I have a momentary toggle switch on my dash and I warm them for 20 seconds in cold weather before cranking.