Intermittent Glow Plug Relay

[Mr. Bone]

Hello,

The 4 month new glow plug relay on my 86 G30 van is not really working. When the van is cold I have to jump the leads on the relay to bypass it. Then when it's warm it sometimes works. Because the relay is new i am stumped. All this started happening when i changed the water pump although i know this has nothing to do with the glow plugs. I'm wondering if there is something in the vicinity of the waterpump R&R area that i could of hit or altered? Could it be battery related. . .although everything powers up easily and my lights don't dim.

I imagine it's something very simple that's eluding me right now. Any suggestions or thoughts are appreciated. Thanks

[john8662]

Is this a military Box van?

I'm curious which glow controller your van is equipped with.

The only thing you could of upset up front with the waterpump r&r would be the grounds on the water crossover (in the vicinity).

Check the water crossover for any senders/switches, some models were equipped.

As usual check electrical connections on the back of the engine, check the grounding strap location on the back of the engine too. The controller needs one good internal ground (on the harness, if i'm thinking of the same controller) or it won't function.

Finally, on the back of the engine above cylinder #8 on the head, there will be a blockoff plate (passengers side), some vehicles are equipped with a inhibit switch, check the connections there. You may also try shunting the connection with a piece of jumper wire, it's a switch, not a sender, so that would rule out that possibility.

J

[Mr. Bone]

Thanks for the prompt and thorough reply. Yes this is a military box van. I will continue with some of your trouble shooting techs and get back with you. thank you.