Hey Guys, I have a 99 7.3. The truck runs fine but the wait to start light is not functioning. I tested all glow plugs, also it has 12v at the 2nd post of the gpr with the key turned on. So the system is working, but for some reason the light in the cluster wont come on?

I checked the bulb in the cluster and it is good. Also I changed the PCM with one out of my other truck that I know works 100% and still no light.

Does anyone know which wire going to the cluster is the wts signal? As I understand it the signal comes from the PCM to power up the gpr relay, there is no wire going from the relay to the cluster to power on the wts light, that signal is sent directly from the pcm also.

Any help or ideas would be appreciated

 

The PCM powers the WTS light. It has no direct connnection or control of the GPR...

https://www.dieselbombers.com/ford-p...tml#post735911

 

Ok, did some more testing, my light will still not come on, but the relay will not shut the power off to the glow plugs. It has 12v on both large post's, even after the truck has fired?

 

The glow plug relay will be on for 30-90 seconds, even after the truck is started.

 

mount an led light in the cab and wire it to the glow plug side of the relay then you will know anytime the glow plugs are turned on