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.

all wires to the transmission have continuity, took it out for a drive again and it started doing it again. I got a P0720 code again for the speed sensor, putting another new one in today. Really tempted to sell this thing but I've got so much blood sweat and tears in this thing.

Did you try going over this...

 

26 minutes ago, Mopar1973Man said:

Did you try going over this...

 

where would one get this miller tool? Ive never done this but I did trace all the wires and I confirmed continuity to the tranny harness. When this happens driving its like its spitting and sputtering rams drop tranny feels like its disengaging then suddenly grabs, gas peddle has no response at all.

Skip the miller tool part. But the wiring diagnostics are what you got to watch. 

Do you have any other codes? Spitting and sputtering is not a transmission or speed sensor issue sound like a engine issue. What is your fuel pressure at idle and WOT on the highway? Any other error codes? 

fuel pressure stays at 17psi only code I'm getting now it the 0720, the spitting and sputtering feels like the tranny in and out really fast or sometimes it feels as if Im stuck between shifts or stuck in a gear, pressing the accelerator does nothing then all the sudden it will "catch" 

The best guy to talk to in Dynamic here on the site he's one of our Tranny Gurus. 

https://mopar1973man.com/profile/2504-dynamic/

well I believe I may have figured it out. I kept getting the 0720 code for speed sensor so I went and bought a new one. Upon removing the old one I could see the magnet on the end was covered in very fine metal shavings (new transmission) so I replaced the sensor and drove for well over two hours and at least 10 key cycles stop and go traffic, raising and lowering the lockup speeds with the controller. Its yet to duplicate my issues so as of now Im gonna hope that was the fix. Gonna order some new amsoil tranny fluid and do a complete change and filter. Fingers crossed...

Might be worth doing a fluid change if there is metal stuck o the end of the sensor magnet. I'm going to assume the magnet in the pan must be full. 

55 minutes ago, Mopar1973Man said:

Might be worth doing a fluid change if there is metal stuck o the end of the sensor magnet. I'm going to assume the magnet in the pan must be full. 

yeah definitely doing a change before I drive it again. Thanks for all the ideas all who chimed in I learned a lot more using my volt meter and checking wires. Truck as of now not for sale hahaha

Real glad you got some positive news to report! Here's hoping to many more problem free miles!

18 hours ago, notlimah said:

Real glad you got some positive news to report! Here's hoping to many more problem free miles!

you and me both man. I've got a camaro on the back burner the last 3 years because of truck issues.

Hey guys, new to the site and the diesel world in general. I have a 99 24v and have experienced the lockup issues described. After reading extensively on this thread I pulled the alternator fuse and truck worked great. Replaced the alternator (Oreilly) and the problem went away for about 3 weeks. While hauling a small dump trailer with approx 1 ton of gravel I began to have some lockup issues while climbing a hill, but the problem went away for the rest of the day. That same evening with a load in the bed of the truck (no trailer) the TC went bananas. Disconnected the alt fuse and plug on back of alt, drove truck with no problems. Reconnected everything, and problem was gone. Drove to a local parts store where they had a good tester and my alternator checked out good (diodes included).

Sooo, I am wondering if anyone has any insight as to why this happened while pulling a load?  And what has happened to cause it to go away?

Also, took the truck to a local shop when the problem first came up and they hooked it to a computer. They told me the computer on the truck (ECM?) had gone bad, so they replaced it. No problems were solved...

I would bet your "new" alternator is still bad.   I have never seen an oreilly's have a tester that can test the diodes on alternators, they just look at output.  Did you verify %100 that the parts store actually tested the diodes?

 

I would guess heat may have had something to do with it, maybe the diodes on the new alternator are on the edge.

Edited March 1, 20169 yr by Me78569

I actually found an Auto Zone that could test it properly (i think). Oreilly said they couldnt help, and looked at me like i had seven heads...the guy at Auto Zone actually has a 3rd gen 2500 and used their battery/alternator tester which showed on the screen that the diodes "passed".

I guess part of my question is what happened to cause it to malfunction more after pulling a load (and even once i was unloaded continuing to malfunction ) and then go away totally when the alternator was unplugged and plugged back in (fuse and leads)?

Also, if alternator is junk, which one is the best to get to eliminate the potential of bad diodes out of the box?

I would guess that heat is what causes the issues to come up.  

 

But that is just a guess.

 

They are probably all the same, hit and miss.

Well I've been lucky but now I think my luck is running out. The last time I had a problem I just charged up the batteries and cleaned the connections and it quit but now it doesn't want to leave this time. I haven't done the test yet. Like remove fuse or volt test. I am looking to order a brand new alternator not refurb. Can I use a denso if I have a Bosch . Also when I start it the gauge sits between 10 and 14 then slowly goes up to 14.

Update....still flawless!    

I'm pretty sure an alternator can test out as good when in reality it's hurting/ confusing your electronics with too much A/C voltage noise. Kinda like you trying to figure out a complex job and the kid next door won't turn down the Boom Boom  music.

Edited April 14, 20169 yr by JAG1

 

I went and tested my alternator today. 

Idle ~.03vac

Slowing going up on on Rpms to 2,000 I saw a few spikes

The highest being .86vac

 

Do you think this is my source of 

Torque Converter Lock / Unlock Issues? Should I just get the regulator/rectifier diode replacement from Larry B?

 

The previous owner must of had this issue too. Noticed the ground wire behind the alternator had the tin foil hat recipe. ?

 

I only had issues when towing a 10,000lb load uphill between 45-55mph overdrive on 

Alternator is done. Time to replace. You can rebuild it yourself but make sure to get both diodes and brush kit. There are other kits cheaper than LarryB as well. I will admit his diode packs are expensive. Make sure to get rid of all tin foil and wiring mods.

Edited April 18, 20169 yr by Mopar1973Man