How can i bypass the GP controller all together, having problems starting the GP relay is on a switch in dash. 1985 F250 6.9, replaced 4 glow plugs about a month ago with ZD1s. Couldnt get to other 4 which some of them wore swollen and i didnt want to push it getting them out.. I think its the controller thats bad. Also having a problem when warm starting it starts right up and idles fine for about 20 sec then it starts chugging. It will stall if i dont keep it running feathering the throttle?? Any ideas would be greatly apprietiated.

 

https://www.ford-trucks.com/forums/9...old-style.html Have a look at this thread, Dave tells you how to do what you are asking. How long since the fuel filter was changed? Are you running any fuel additives?

 

yes deisel kleen every fill up, white bottle in winter grey in summer.. i already ran a manual switch like it says in tht form, i think im gonna try to update the glow plugs to a later year..

 

what would be the process of updating to the new style glow plugs?

 

Your dash switch, properly wired, bypasses the controller and triggers the relay directly.

 

so could i just unhook the controller? Whats properly wired.. i unhooked the purple wire on the relay and wired it to switch in dash.. switch in dash is one wire going to relay and one wire thats assc. hot? is that right it turns the glow plug light on and heats them up.. well used too.. Also i replaced the GP relay with a starter relay is there a problem with that??

 

Starter relays and glowplug relays are different, so the starter relay will not work for glow plugs.

 

^^^^ +1; Starter relay can't handle the current draw of the glow plugs, esp. for the amount of time they're energized.

As to the wiring, yeah, if the switch wire is going to the relay terminal that connects to the controller, you're effectively bypassing the controller. So it's out of the picture, and is probably not part of your starting problem. You could, just to be sure, try disconnecting that purple wire from the controller, but then you're completely dependent on your dash switch for the GPs.

But I'd start with a real relay capable of handling the load. A lot of guys use a Western Plow relay.