Just got done replacing the ignition switch. It did not solve the problem, but it did raise the voltage on the purple wire by 0.2 volts. Instead of reading 12.1 volts (which is actually 10.5 volts) it now reads 12.3 volts (which is actually 10.7 volts) at purple wire at solenoid stud. Likely because of what you just said. (Tiny bit of corrosion on old switch)

Just tried the jumper wire from main stud to s stud and that did not get it to start.........so that means the slightly low voltage on the purple wire is NOT the issue....... correct?

***Added information - I only had the roll of 18 gauge wire I bought to fix wires under fuse box.....to use as jumper wire.......is that adequate?

 

More than likely not the issue,

Pull the dust cover off and take a look in there, lets see if the starter is engaging the flywheel when you hear the loud click?

Neal

 

Ok, after peaking in the dust cover while she tried to start it, over and over, the part that meats the flywheel (Bendix?) Does not extend far enough to meet the flywheel from what I can see. There is a tiny slot on the bottom of the starter, end closest to flywheel, where I can see it move a tiny bit every time you here the click. (I would guess the slot is to be able to see if Bendix moves without removing starter). It only moves about a 1/4 inch and I can't see perfectly, but from the angle I can see, it does not appear the Bendix is extending enough to mate with the flywheel. The flywheel seems in excellent condition. The 20 teeth or so I can see all look good. (Couldn't get the truck to start to see if it wobbled at all or if the other teeth in different section were perfect as well). Tried about 15 times with no start, even with a few light taps on starter. It's deffinently progressing worse.

To further try to give you as much info as possible to judge this test.....I will try to describe the view in the slot on the bottom of starter as a percentage. At rest, the Bendix is about 20 or 30% filling the slot. When you here the click noise, it moves over and fills about 60-70% filling the slot. (Im guessing it should be more like 90-100% full in slot for a proper engagement)

 

OK your close to finding the issue
The Bendix has to fully engage the flywheel to make the starter motor spin, so we need to figure out why the Bendix is not fully engaging
The best option is to pull the starter off the truck and take it to a local parts house and have them test it.
If the starter checks out good then its possible the Bendix is binding on the flywheel and need shimming

Neal

 

Ok, I will do that. Do have a few questions though. How could it needing shimmed, go from 99 out of 100 times starting and over 6 months get to the point it won't start at all? Also I thought only cheap aftermarket starters (or universal ones for old muscle cars) needed shimmed and they usually come with the shims in those cases, no? Or maybe a better way to word it in this case is, if it does need shimmed, wouldn't it only be because the transmission guy didn't do something perfectly?

 

first lets get it checked and make sure its not the starter causing the issue
Then we can move from there, it may not need shimming
Did your trans guy put the correct bolts back in the starter, starter bolts are knurled at the block end and fit tight, if not the starter can move around

Neal

 

Got starter bench tested at O'Reilly's this morning. He tested it twice and both said "passed". (He did it twice so I could see the Bendix fully intend for myself in the little "window"). He said it said something like 14 volts and 78 amps in case that helps. What now?

 

** fully EXTEND

 

14 volts? Should be around 10v.

 

What do you think that means? Should I have it retested again? (Even with the Hummer not running it has 12.6 volts and it only drops to 12 volts when the starter does actually start). 10 volts seems a bit low to me. But 14 volts does seem a bit high. What all this means.....I'm clueless lol