Ok Gang...I've got a for sure way to diagnose torque converter lock up issues where it lock and unlocks at about 45-50 MPH. I had a gent call me yesterday with this problem and he's replace both batteries, alternator and the APPS sensor. Attempted all the different wiring issues (adding ground, tinfoil etc.) nothing worked. Like I told him the truck ran 11 years without all this stuff and doesn't require any wiring change to make it work. What it needs is the damaged part to be replaced. So he's returned the wiring back to stock setup.Now I told him to unhook the alternator fuse and take it for a ride... Guess what... No problems! Even though he replaced the alternator it has a damaged diode in it and it bleeding AC noise into the electrical system.So before doing any wiring mods, tinfoil, adding grounds, adding filter... PLEASE! Bench test your alternator! This is the second time I've suggested this and both time resolved the torque converter lock up issue.

Thanks mopar1973man

Edited April 18, 20169 yr by Fizzle

The two links in this thread is what I used to rebuild my alternator.

https://mopar1973man.com/topic/11227-alternator-rebuild/#comment-130832

It worked out really well and was pretty easy to do.

@Hawkez Could you do us a favor and create a rebuilt article for alternator suppling those links? This way everyone can find then in the article database.

Hey guys.  So I am on my third alternator from Oreilly's...fortunately they have just been swapping them out on warranty when I explain the problem.  I am looking into a local shop that can build the diodes for me, but would be interested in the contact info or nudge in the right direction for purchase through sources you guys have had success with (LarryB etc.)

 

The odd part about this last time the problem came up is that it had only been about two months since I swapped it, and when I popped the hood to pull the fuse both battery terminals were covered in corrosion, and after pulling the fuse, the lock up issue continued to happen.  I came home that day, put new connectors on all for terminals, cleaned everything really good, and ran the truck with no alt. fuse, and problem disappeared.

 

Is there possibly something else going on in addition to the alternator?  A coworker suggested an open ground might be aiding in the failing alt.  I really don't understand vehicle electrical systems, so any help or advice would be greatly appreciated.

Here is your master ground for the PCM, ECM and VP44...

This points out the added requirement of keeping the battery terminal clean and in good condition. There is no computers have grounds that bolt directly to the body. Only secondary systems like lights and other minor equipment will. Don't bother chasing grounds everywhere...

Edited July 17, 20168 yr by Mopar1973Man

My PCM has a flat insulated wire that goes from one of the mounting bolts to the firewall just above the turbo. I always considered that a ground and I did not add it. ???

Just now, dripley said:

My PCM has a flat insulated wire that goes from one of the mounting bolts to the firewall just above the turbo. I always considered that a ground and I did not add it. ???

 

 

That is not a circuit ground. The PCM is mounted on plastic fasteners in the bracket so to get the case a ground plane again that strap was added in hopes of noise shielding. That ground strap has nothing to do with circuit wise ground. Even my truck has the same strap as well. 

 

Here is the PCM circuit grounds. Take note to Connector 1 and pins 31 and 32 going to Ground G115.

 

 

8 minutes ago, Mopar1973Man said:

 

That is not a circuit ground. The PCM is mounted on plastic fasteners in the bracket so to get the case a ground plane again that strap was added in hopes of noise shielding. That ground strap has nothing to do with circuit wise ground. Even my truck has the same strap as well. 

 

Here is the PCM circuit grounds. Take note to Connector 1 and pins 31 and 32 going to Ground G115.

 

 

Thanks clearing that one up Mike. Always wondered about that wire. I do see the circuit grounds you are speaking of.

So i have combated this issue for the past 3 years. I have four second gen trucks for my company and 4/4 had the torque lock up issue. I have tried many fixes that were merely bandaids for a few weeks or months but it then came back. I have tried so many of the tips and tricks. Spent countless hours looking for answers and just a few months ago I tried the dumbest thing. It cost me less than 10$ and i haven't had a hick up. I didn't unhook any batteries. It was happening that same day. I just made some

modifications  and when i went for a drive it was gone. it has been over a month with out a hick up. Ive done it to 3/4 since one truck is out of commission. I just talked to a friend who's second gen had started doing it again this week it is driving him crazy. I sent him so photos and i got a text back an hour later. I had been doing it today and once he did what i told him it was gone. Are there still a lot of you fighting this issue right now??

Sooo are you going to say what you did or is it a secret?

you having the same issue 

No I'm not

It makes us all scratch our heads as to your intentions when you make a post like that.  

 

We have a lot of trial and error pointing to bad alternators causing %99 of the lockup issues in 2nd gen trucks.  From what we have seen in the past there is no $10 fix that resolves the root issue of burnt out diodes in the Alternator.  

 

We are all ears, but you will have to let us know what you found to work.   You will find that we are pretty close knit group so we like to see info spread rather than hid.

Exactly! If you found something that fixes this issue then let us know. That's what these forums are all about! 

 

Just seems like you're taking a weird approach to this whole thing. 

Guys, took my alternator in to Napa, AC was 0.9 but their tester said it was good!!!! WHAT GIVES? is that even possible? 0.9!?

Guys, took my alternator in to Napa, AC was 0.9 but their tester said it was good!!!! WHAT GIVES? is that even possible? 0.9!?

AFAIK NAPAs test isn't checking for ac noise specifically and its checking it under full load, so you'll get different results.

4 hours ago, notlimah said:

AFAIK NAPAs test isn't checking for ac noise specifically and its checking it under full load, so you'll get different results.

So 0.9 vac is ok? I took it to oreillys after and they came up with Ripple... .39 

damn. Cant believe how difficult this electric stuff is.

 

 

.9 is not ok that alternator's diodes are burnt out.

I tried calling Michael Nelson about this last night but he's very busey. I wanted to ask him about the painted alternator mounting bracket. I found that the bracket does not give a full connection to ground and has some resistance.

 

I also read a lot about the value in running a separate ground from the Alternator housing to the negative battery post. Read there is a lot of benefit to that since batteries absorb most of the AC noise from the system.

 

So I don't really know without talking to Michael because he is the electrical engineer. My truck has never had this problem and my alternator has a separate ground added.