Today I went to fire my truck up and everything seemed normal. The plugs cycled for about 8 seconds then the WTS light went out. I started the truck up and they kept cycling like normal. But usually it only does it for about 2 minutes while the trucks still cold. But I got to driving and they just kept on cycling even though the motor was warmed up at that point. So I came home and even after I shut the truck off they still kept cycling. About every 10 seconds they will come on and click. I unhooked the battery cables so the wouldn't go dead. I'm guessing it's the GP controller but not to sure. How can I trouble shoot it and fix them from keep cycling. Thanks

 

Either GP controller or the coolant temp switch down on the head that tells the controller when to turn on...

 

So how can i test to see which it is? I've never heard of this temp switch

 

The controller doesn't get a signal from a coolant sensor. It senses temp by the resistance of the glow plugs. (the resistance changes with temp).
Pretty sure your controller is bad...

 

I found out the clicking is comming from this thing that's bolted to the fire wall. Not sure if it even has anything to do with the GP controller

 

What thing bolted to the firewall?

 

I'm not sure what it was. the previous owner must have put it on. It made the same clicking sound as my controller and was ran to a switch inside the truck. I unhooked it and no more clicking and draining the battery. Thanks for your suggestion anyhow.

 

may have been an old circuit with a circuit breaker that was tripping and resetting, trace it back to find what it is.

 

Well that wasn't the end as I had hoped. Went to cold start it after unhooking it and the truck did not want to start at all. It has to have something to do with the GPs. It's like I didn't have em. The WTS light still came on for about 10 seconds though. But if I hook this thing back up it does the same thing before I unhooked it and drains the battery but starts fine. I would post a pic but not sure how off my iphone. Any suggestions ?

 

is your truck still the '94 like your screen name suggests?

it sounds like you removed the power supply going to the GP controller off from the fender mounted starter solenoid.a ring style terminal with a fuseable link which is on the always powered side.
that was a wise move actually.you probably saved your glow plugs.
you can fully diagnose the system here:
https://www.ford-trucks.com/forums/1...-tutorial.html

to temporarily start your truck (while you wait to order a new gp solenoid or controller,if needed) simply hook the ring back to the solenoid like it was.start the truck (as if you always do when working correctly) and while still running,remove the ring terminal again.
you wont need the gp's (ignore the WTSL) for the rest of the day,unless it's cold and has been sitting.in that case then just repeat.

 

Yeah this is exactly what I did except it's on the firewall not fender. What's causing it to click/stay on 24/7 when hooked up? I don't see any wires running straight to the controller. I might not be looking hard enough though. Any idea on whats broke/needed to fix ? A relay ? Controller? Or this power supply thing?

 

Forgot to mention everytime it would "click" the switch in the cab would light up. And yes it's a 94 model.

 

so someone mounted a relay/solenoid on the firewall and to glow the plugs,you have a devoted switch/push button that you press/hold to glow the plugs it sounds like?

well,i know what i would do.id rip the additional manual mess out and fix the oem system.it lasts for 20+ years and it just works issue free.someone probably used a starter solenoid.take a look at it and i bet you'll see a little S on a post.

 

Well what I thought was strange was before all this started acting up I would never touch the switch to get glow plugs. My oem system worked flawlessly. The truck would start up -5 degrees F w/o the block heater

http://s880.photobucket.com/user/_ed...a4fa1.jpg.html


That's the thing I'm taking about on the firewall. And whAt do you mean someone probably used a starter solenoid "s" on what? I appreciate your help man

 

that is a circuit breaker. whatever it is hooked to is drawing too much power, overloading it, and tripping it.