2003 GMC HD2500 4x4 electrical prob

[scott k smith]

What is wrong with my truck? For approximately two months my truck would not start on the first and sometimes second attempts even though it would turn over. Eventually it would start. This happened until yesterday when trying to start it and it would not even turn over. All electrical accessories however did turn on when the ignition switch was turned on. I assumed the starter had finally gone out and therefore replaced it. Still the problem was not solved. I replaced the battery. Still the problem was not solved. I also replaced the ignition relay and starter relay. Once again problem not solved. Please help and if more details needed let me know.

[ctwright]

does this happen every time you go to crank it, like if you just turn it off run into a convenience store and come back does it do it then or only after it's been sitting for a long time?

[scott k smith]

Well, it was occurring only after sitting for a while . But like I said it wont start or even turn over now. I'm not sure if the sluggish starting problem and my current problem are related or not. As I stated earlier , it won't even turn over now,much less start.

[ctwright]

you should take a test light, see that it lights on the small wire at the starter solenoid with the key in start, if it doesn't then you need to check all your fuses, one may have blown during all of the hard starts you were having

[ctwright]

from your ignition switch you should have a yellow wire going to your fuse block, to a 10amp fuse, should be fuse number 8 I think. from there yellow wire going to either your clutch switch or transmission relay switch, from either you will have purple wire going to the starter relay, which energizes the coil inside the relay when you turn the key on. Also there is a red wire from fuse 6, a 40 amp fuse under the hood(which should be good if all your gauges are coming on), that red wire going from that fuse goes to one of the starter relay terminals , the starter relay is under the hood, which is always hot. there is another purple wire that goes from the starter relay down to the starter solenoid, it gets its juice from the red wire when the contacts close in the relay.

If you use a test light, ground the clip, and then test the yellow wire going to your clutch or transmission switch and it lights with the key in start, but doesn't light on the purple wire on the other side of the switch, the safety switch is bad(Provided you are in park or neutral and the clutch is pressed in like it should be when trying to crank). If it doesn't light up on the yellow wire then you need to look for the fuse.

[scott k smith]

Thanks to all for your input. I will put all suggestions to use first thing in AM .
Stay tuned and I will give update tomorrow.