no start, then later start with high rpm?

[Black dawg]

you did this while it would not start?

 

[SPR1NK]

Yes, it was one of the first things I checked

 

[bbjordan]

Just because the test light lights up doesn't mean the glow plugs are getting enough current. A bad power supply feed connection would give you this condition. Did you pull apart the power connector by the passenger fender and check it?

How long do you glow the plugs?

How fast is the engine turning over when you try and start it?

 

[SPR1NK]

I had that power connector apart about a month ago when I redid all the wiring in that harness and moved the relay to the passenger side fenderwell, it all looked fine then, but I'll check it again

I usually run the plugs for about 10 seconds if the truck hasnt been ran that day

I don't know exactly how fast, but it turns alot faster now than it ever used to since I have brand new batteries in it