My 1989 7.3's glow plugs are looked up to a push button. But sometimes when i turn on the key it will glow the system all by its self. The wait to start light doesn't light up though. So when it does this i just let it and then start it up. But 85% of the time i have to do it. Any ideas why?

 

Need to know how you have it hooked up

 

It has a wire hooked up to a terminal running to a push button switch and then to a ground.

 

intermitant operation of gp controler, bad conection at controler,or broken wire,, the push button is a work around, it just trips the same relay that the controller does,,to heat gp's

 

I thought by bypassing the one plug and running it to a push button that eliminated the GPC's role in the whole system?
So how could it be intermitant operation of the gp controller if it's not supposed to be working in the system at all? i thought that was the point for a lot of people, GPC burnt out and they want a cheap way to make it work

 

Did you disconnect that little purple wire going to a terminal on the solenoid?


That purple wire is what controls the glow plugs automaticly.

 

If the controler is intermitant its a bad conection or broken wire you will have to check to find the problem...

 

On the new system the relay is hot and the controller sends the ground to the relay when it wants the GPs on. To go manual you disconnect the ground wire (white wire) from the terminal, tape it up and set it aside, and run a new wire from this terminal to the push button switch then from the switch to a good ground. Sounds like your push button was added, but the old ground wasn't disconnected and the controller is still working intermittently.


Picture courtesy DaveS