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.

No thank you!      

I've updated the article to provide link back to these post and the photo of the blown diode pack.

Just got back from a trip after getting the Alternator rebuilt, and the tranny was flawless both ways, not once did it unlock and lock.  I am, becoming a real believer.  Thanks for the help on getting this finally fixed!!!  

Holy carp, Michael has been right all along???????

I guess I can stop wearing my tin foil hat, remove the foil from my ground, pull the 14 Radio Shack noise filters & my lead lined condom.........

 

Ed

Edited December 1, 201410 yr by Yankneck696

LOL Tin Foil Hat!!! Good stuff right there.  

I'm retesting my alternator tomorrow, thanks for all hard work!

Holy carp, Michael has been right all along???????

I guess I can stop wearing my tin foil hat, remove the foil from my ground, pull the 14 Radio Shack noise filters & my lead lined condom.........

 

Ed

 

Because of this one fix, and the great help on this forum, I am going to donate when I get a chance.  Michael, you ROCK!!!

Been chasing the dreaded TCC  issue on and off for years.  Started off with BD noise filter...it worked - for awhile, then issue came back.  Found this great thread - checked alternator....AC current 0.013 VAC at alternator, 0.029 VAC at battery - alternator diodes good, but problem still there :-(.  Reading everything I could find to finally solve this, and getting desperate as I am about to tow my new 42' gooseneck trailer for the first time soon and I cannot have the converter doing this and not locking up.

 

Latest fix attempts - 1) did APPS reset and 2) relocated the portion of the big ground cable running right next to the alternator away from it (one of many fixes I discovered).  Drove truck yesterday after doing those two things, and voila - back to normal  .  Not sure which one or if both did it, but I hope it lasts this time!

I can't seem to get rid of this issue either, I replaced the alternator twice, and ended up returning them both and going back to my original because the issue stayed the same.  I even ran with the fuse pulled like this thread suggests, with no change (it still locks/unlocks).  The transmission has been rebuilt, TC replaced, I've wrapped wires near the alternator with tin foil and duct tape, I even put a small capacitor in between the tranny line and ground to try to smooth the current (and later removed it, since it had no effect either).

 

The APPs is pretty new too, since I replaced it when I first bought the truck (dead pedal).

 

I'm completely out of ideas, what else can I do?

I can't seem to get rid of this issue either, I replaced the alternator twice, and ended up returning them both and going back to my original because the issue stayed the same. I even ran with the fuse pulled like this thread suggests, with no change (it still locks/unlocks). The transmission has been rebuilt, TC replaced, I've wrapped wires near the alternator with tin foil and duct tape, I even put a small capacitor in between the tranny line and ground to try to smooth the current (and later removed it, since it had no effect either).

The APPs is pretty new too, since I replaced it when I first bought the truck (dead pedal).

I'm completely out of ideas, what else can I do?

Test alternator for diodes at good shop that know what they're doing, I tested mine at orilys and it was good, then on some old school analog machine and nidle was almost all the way on bad for diodes, but still was good on charge. And make sure if you use voltmeter to rev the engine up slowly and you'll see ac voltage will go up.

Did you reset the APPS?

Ed

Test alternator for diodes at good shop that know what they're doing, I tested mine at orilys and it was good, then on some old school analog machine and nidle was almost all the way on bad for diodes, but still was good on charge. And make sure if you use voltmeter to rev the engine up slowly and you'll see ac voltage will go up.

 

 

Wouldn't unplugging the alternator fuse rule out a bad alternator (since it made no difference)?  I'd also *hope* two new alternators in a row wouldn't both have bad diodes, of course that isn't guaranteed.

 

 

Did you reset the APPS?

Ed

 

Yes, it makes no difference, it might go away for awhile but comes right back.

"New" alternators from the big chains are made in China. Junk. Do the AC voltage test & you will see for yourself.

This is why they don't even want a core.

 

Ed

"New" alternators from the big chains are made in China. Junk. Do the AC voltage test & you will see for yourself.

This is why they don't even want a core.

 

Ed

 

 

I don't disagree with you there.   But  wouldn't pulling the alternator fuse disconnect the alternator from the system and rule it out as a cause for electrical interference?

1 person reported back that his brushes were so worn that they were making noise & with the BAT wire & the control plug removed from the alternator there was no lockup issue. Replaced the alternator & all was fine. Remember, AC voltage can be transferred through inductance (Think radio broadcast). That is why I always suggest to fully disconnect at the back of the alternator.

 

Ed

This is why relocation of the wiring or wrapping with tin foil won't work. The wiring would have to be like a CB coax that has a shielded jacket with reference to ground. So any AC production can be absorbed into any wire or circuit. Hence why BD noise filter works to filter the power into the PCM but leaves the rest of the electric system to fry from AC noise.

With 200 watts on my CB in an old Grand LeMans, I had a trunk mount antenna. I would key up & the rear defog light would glow right along with my modulation.

 

Ed

Been chasing the dreaded TCC  issue on and off for years.  Started off with BD noise filter...it worked - for awhile, then issue came back.  Found this great thread - checked alternator....AC current 0.013 VAC at alternator, 0.029 VAC at battery - alternator diodes good, but problem still there :-(.  Reading everything I could find to finally solve this, and getting desperate as I am about to tow my new 42' gooseneck trailer for the first time soon and I cannot have the converter doing this and not locking up.

 

Latest fix attempts - 1) did APPS reset and 2) relocated the portion of the big ground cable running right next to the alternator away from it (one of many fixes I discovered).  Drove truck yesterday after doing those two things, and voila - back to normal  .  Not sure which one or if both did it, but I hope it lasts this time!

Update:  truck ran perfect for several days, and then the dreaded TC cycling was back :-(

 

Rechecked alternator - still good, so decided to do another APPS reset.  Runs perfect again!  Since I don't have a lot of history on this site, the only things I have done out of the host of fixes floating around for the TCC issue are the BD noise filter several years ago, and most recently, re-routing the large ground wire away from the alternator.  All my battery cables and terminals are brand new and the truck overall is still like new with less than 32k on it.

 

Question for MoparMan or anyone:  is it possible the APPS itself is going bad?  Is it possible the alternator could still be going bad even though the voltage checks are perfect?  I have no other issues with the truck other than the TC cycling - no MIL codes, no dead pedal, no limp mode, no nothing.  Any other ideas?  I really hate shot-gunning potential "fixes" and trying the other ideas like re-routing more grounds, wrapping wires, etc. without understanding root cause, but I am perplexed at finding the root cause.

I don't disagree with you there.   But  wouldn't pulling the alternator fuse disconnect the alternator from the system and rule it out as a cause for electrical interference?

 

Only works if you kill the alternator as well. So both the fuse and the field lead must be pulled.