Here is a diagram subford has. We just had a thread on the newer truck starter wiring down in the electrical forum. It looks like the relay on the fender us used to activate the solenoid coil in the starter.



About your problem. It almost sounds like mechanical interference between the starter and the flywheel. But let's do one more test. Either get another person to turn the key while you watch, or when it's dark outside, turn the headlights on. Then try to start the truck. From all your previous posts, the headlights should stay pretty bright. That would tell us that the battery is good, and some of the cables are good. It would also tell us that the starter is not even trying to turn.

The solenoid on the starter pulls the starter gear out to the flywheel. It also makes a large connection inside the starter that puts the large bat + wire onto the starter motor windings, making it turn.

If you do not mind taking it off one more time, let's test the starter yourself. If you have seen it work at the store, and feel confident the starter is working, you can skip this test. Take some jumper cables and while it's laying on the ground, hook the - cable to the housing of the starter, and then the - of the battery, and then hook the + cable to the + of the battery, and hook the other end to the + battery connection of the starter. Nothing should happen.

Then take a small jumper wire, and jump the bat + connection on the starter over to the other small terminal. When you do this, the gear should fly out the front of the starter, and it should start spinning.

If all this is working, and the large + cable to the battery + is in good shape to the starter, then it has to be a mechanical problem. If the gear is going up and hitting the flywheel, and not letting the solenoid slide all the way back, it's not going to make the electrical connection inside the starter to put power to the starter motor. What you could try is loosening the start bolts a little bit as a test. This will let the starter move around a little bit. That may be enough to see if the starter gear will slide into the flywheel. If this works, you have some head scratching to do and here is a question I have:

Did this truck ever start since you had it? Or did you buy this as a project? If it was a project, I would look for something that is not original. Like someone may have put the wrong flywheel on it when they changed the tranny or something.

 

Thanks for responding Dave, we obviously needed some help here.

 

This was a running truck. I run a few errands one afternoon and it was fine. That night I was going to work and it wouldn’t start. It has been the same since. It has had 2 new starters, a new ground and positive battery cable, the battery tested okay at AutoZone. I put the battery in my old Chevy and it started it up really well. The Chevy has 10 ½ to 1 compression. The battery spun it so well I may end up buying another battery like it for the Chevy.
I have tested both new starters on the ground twice and had them to the zone for testing at least once each. I pull the starter loose the other day to see if it would spin or hit the fly wheel. It still did the same thing. It kicked out but wouldn’t spin. I loosened the bolts farther out to make sure it wasn’t hitting the flywheel and it still wouldn’t spin. I pulled the starter and put it on the ground and jumpered it and it spun. This was the third time it has spun on the ground for me.
I hooked up a ratchet to the nut on the alternator and spun the motor over with the starter off to make sure the flywheel turned.
I am going to try to replace the wire running from the relay to the starter and from the positive post to the relay tomorrow to see if that does anything.
If this don't work I don't know what I'm going to do.
I am beginning to think the truck just doesn’t want to haul me around anymore.

 

What year did u say was the truck? Here's the thing, if u have tested all connections at the starter and it spins outside the truck, the starter is fine. If u put a new battery in it and as u said tested it on ur chevy, it's fine...Now if u wouldn't mind clarifying something for me...u say the starter will kick out but NOT spin while it's in the truck? But is fine outside on jumper cables? If this is the case, i would be checking the ignition circuit...the ignition switch controls the engagement...the ignition circuit uses battery voltage to energizes the relay coil or solenoid windings which activate the switching lever that engages the gear...it seems to me if u have replaced the battery, starter, and cables and are known to be good, u have an ignition switch problem...some systems also have safety start switches in many different forms, u'll have to find out which kind u have. they have been known to go bad..but my advice is too check ignition switch...just outta curiosity...what type of weather has it been acting up in? Hope this helps...cya later...

 

the truck is a 97. If you jump the relay wouldn't that be bypassing the ignition system?

 

yes if u take a remote starter and hook it up to the battery post on the relay and then the ignition system post that will bypass the ignition circuit. U can also use a screw driver, kinda hokey but it works. If the engine cranks over then u know the motor circuit works. But if it doesn't start by using the key, u know it's the control (ignition) circuit. Have u tried bypassing the relay? Does it crank over?

 

Yes I tried bypassing the relay, it still didn't crank over.

 

I am thinking now it may be a wiring problem with the starter. You said the starter is kicking out, but will not spin. This tells me the smaller wiring from the relay is ok, but the main battery power for some reason is not getting to the motor windings. That's why I thought the gear must not be kicking out all the way. But if it is, you need to check out the circuit from the bat + directly to the starter, and where this is hooked up to the starter.

 

I looked up your application on www.partsamerica.com. They have two possible starters for your 97 truck with a 4.2. One is manufactured before 7/15/96 and one has a manufacture date after 7/15/96. I can't tell what the difference is in the pictures, but could this be causing a problem?

 

Exactly
The main battery cable has one branch that goes to the starter relay on the firewall and another that goes to the solenoid on the starter.
I would take a test light and see if it lights when touched to the big positive terminal on the solenoid on the starter. If it doesn't, then you have a problem with the main cable from the battery to the starter solenoid. If you have power there then have someone turn the key to the start position while you check for power again. If you had power there with the key off but don't with the key in the start position then you have a bad connection, probably inside the terminal at either end of the main cable.

 

i have a truck very similar to this one i have only had this problem one on my truck, the problem that i have is that one my batt. termanls had a lot of build up on them and also i did not have a good connection on my alt. sounds weird but when i hooked it all the way in it fired right up. also it would not hurt to hook up some jumper cables

 

I finally found it. I bought a battery cable with the post clamp already crimped on. It was loose in the crimp. I tugged it to get a little more cable and it fell off.
Thanks for all the help fellas.