Glow plug relay question

[nathan619]

I have a 99 F350 that won't start when cold unless plugged in. It starts fine after the initial start.

I bought the Haynes Techbook for diesels and I was checking the glow plug system. I had voltage at the GP relay terminal with the blk/orange wire while the key was off. I turned the key on and checked for voltage at the other large terminal (with the brown wire) and had nothing.

It stated if I had no voltage on that terminal, "disconnect the electrical connector at the base of the relay and check for battery voltage at the red/light green wire terminal, on the wiring harness side of the connector." Where is that "connector"? I see nothing that looks like a connector at the base!

BTW- I was hooking the ground side of my meter to the negative side of my battery.

THanks...

[vitalidle]

The orange wire is always hot as that is the battery feed. The other two small posts are trigger wires one is the ignition and the other is from the pcm. If you don't have power to the other large post and you don't hear it click with the key cycled to the wait to start position then you can pull the wires off the two small posts and apply two jumper wires from the batter if you get power to the other large post then the relay is good and you have issues with either the pcm circuit or the ignition circuit.

[vitalidle]

There is a writeup here let me find it for you.

[vitalidle]

Here is one Troubleshooting GPR & GP's and another 7.3 glow plug system diagnosis

[nathan619]

I replaced my GP relay and everything works fine now.

Thanks everyone.