Testing glow plug relay?

So I've burnt another altenator and have been told the gpr can do that if its staying on. I was wondering is there a way for me to test it or do I just need to replace it and the altenator and hope it doesn't burn up again? Thanks.

Get your test light out, there should be power to the ONE of the large post's all the time, and only power to the other large post when the GP's are on, so I guess if you start your truck, wait say 5 minutes then check to see if you still have power to both large post's. There is probably a better way to do it, but that's how I've done it in the past.


Dave

The two small posts are for the relay coil. The PCM activates the relay by supplying the ground. Kinda of backwards to what we are used to seeing where the power side is switched.

Install a glow plug warning light... one of the cheapest and best mods I have done...

Glow Plug Warning Light

here ya go.. pick this up on post #58

http://www.superdutydiesel.com/forums/911-diesel-down/23955-missing-no-power-6.html

I figured it out with the test light. I messed up when I replaced my cables. I accidently put the fusible link and wire that runs to the gpr from the starter relay on the wrong post on the starter relay. Thanks and now I know.