Well, with the new alternator, the voltage ran at 14 volts for exactly 5 days, and now it's back to its old tricks - registering barely 12 on the dash voltmeter. The O'Reilly people tested the alt in the truck and it showed 13.8V

So, I figure it's connections and grounds, which I cleaned. Now I am going to start replacing the cables, probably one at a time.

I already had the inst cluster itself out and all of its connectors cleaned.

Questions

1. Are there any grounds in the cab (under the dash) that I need to look at? I didn't find any

2. Are there any fusible links that I need to check that may have failing fuses in them or dirty connections?

3. What is the length of the ground strap that goes from the back of the intake to the frame

The most important cable is the one from battery pos to battery pos, battery to alternator and battery to starter. Those are corroding on the inside so you won't be able to see it. I replaced the first 2 with 2 gauge cables.

Check all the ground connection so they don't have any resistance. The ground of the inside instrument is on the back next to the fuel filter.

where is the dedicated ground to the pcm, in the interior of the truck?

My last sentence on Post #2.

This comes from TurbineDoc post in TTS forum.

there are ground straps on the turbo side of the engine check those for wear and breaks. i had to take 2/0 cable and make a ground from the back of the engine turbo side to frame that helped out and never trust the gauge in the truck those things are never fully right. ive cleaned and never siezed all my grounds on the alt. and battery nothing ever changed. i bet its not getting a full ground from engine to chassis.

SO... 2 questions remain

- what length of cable will I need to replace the braid

- how do I get the braid off - the trans dipstick tube is mounted on top of the braid's connector. the grounds thread says "you can do it without removing the tube" but it does not exacly say how ...

Don't mean to promote the other forum but TurbineDoc wrote up a nice thread about all the grounds. May be you can mozy on to the TTS forum, it is in their technical library.

Well, I think I have almost all the cables replaced and all the grounds cleaned and/or replaced.

Replacing the driver side to alternator cable (replaced the wimpy oem cable with a 4ga cable) and driver side to the relay box cable had the best effect on the voltage. The dash gauge now shows about 13.5-13.8, and it is 13.8 at the batteries.

Then I also replaced the pass. battery to body wire with a 4ga cable, and added a cable for pass. battery to the frame. The braid on the firewall is still there but it is so awkward to get to the middle of it that I added another ground cable instead.

I think that electrical-wise I am all good to go with this truck now!

Don't mean to promote the other forum but TurbineDoc wrote up a nice thread about all the grounds. May be you can mozy on to the TTS forum, it is in their technical library.

. . .which you can't get to without going through the whole damn registration process. It will take less time and effort to go under the truck and hunt them down. Two things annoy me about sites like this. First, the registration requirement to SEE stuff, second, the way guys signature files brag about every last little damn thing they put on their truck, so when you try to do a search you get 50,000 hits, and 49,990 are just parts lists.

. . .which you can't get to without going through the whole damn registration process. It will take less time and effort to go under the truck and hunt them down. Two things annoy me about sites like this. First, the registration requirement to SEE stuff, second, the way guys signature files brag about every last little damn thing they put on their truck, so when you try to do a search you get 50,000 hits, and 49,990 are just parts lists.

Don't shoot the messenger, if you don't like it then move out!!! LOL!!!

Got the voltmeter working right, finally:

http://www.dieselplace.com/forum/showthread.php?t=383933

I just got out from under my Sub a few minutes ago. The starter that I put in just 4 months ago went bad, and the Delco guys replaced it. They said that it failed because I didn't have a ground on the brush end of the starter (former owner apparently cut off the bracket that went there).

However, while I was doing this, I used 4/0 cable and made a new cable to the starter solenoid, new grounds from batteries to engine, and new crossover. I took the 4 AWG cable which used to go from battery to solenoid, attached it to the starter ground lug and ran it to the pax side battery. I also rerouted the starter switch wire, so now if I ever have to take it out, I won't have to worm wrenches in to disconnect wires under the engine -- just disconnect the two cables and wire from inside the engine bay, then dive under and pull the two bolts.

Linking to the "solved" thread, for the benefit of Those Who Use Search :))))

http://www.dieselplace.com/forum/showthread.php?t=383933