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.

I tried the same test on my sisters car and my wifes last night and both vehicles including my truck was saying around the 29. acv?? I am doing something wrong, any idea what it is?

I tried the same test on my sisters car and my wifes last night and both vehicles including my truck was saying around the 29. acv?? I am doing something wrong, any idea what it is?

Just like this... Both my 96 and 02 respond the same way.

http-~~-//www.youtube.com/watch?v=UveGtGuswBw

So if there is more than 0.1 VAC then I would consider the next step of having the alternator bench tested. The bench tester has be capable of testing diode wave pattern. Like other old bench testers just check for VDC output voltage and if it mark the alternator was good. With all the electronic vehicles the alternator has to be clean power now. I know like my local NAPA upgrade to the newer bench tester and can check diode patterns.

check my truck last night with a buddies meter (fluke) and it checked okay.... .017acv, what other ideas do we have for the problem? Can alternator problem come and go?

Next time the torque converter lock and unlock problem pops up try the removing the alternator fuse.

I tried measuring VAC and got > 0.4VAC right on the ACC PEDAL POS on PCM connector C1,pin 29, wire color Org/Dk Blue to ground at Battery negative. With the filter it was <= 0.01 VAC. I was tempted to measure PCM ground to ECM ground on VAC but would have taken some time disassembling stuff for access which I did not have. The filter has been doing a great job.By the way, when initially measuring with the grid heaters cycling the VAC accross the battery can be > 0.5 VAC as the battery goes from 13 VDC to 10.8 VDC as the grid heater takes a lot of amps (150 amps or more). I had to wait until it finished before getting meaningful readings.My truck appears to have a poor ground connection between The PCM and ECM from ground corrossion but others may have bad alternators etc.. I cleaned the PCM ground to the firewall sheet metal screw but that made little difference. Probably a ground splice that I can not seem to find easily.I must say I have to thank this site for the information from dedicated people like Mike Nelson (and members) that allowed me to fix this irritrating problem. It is so nice to be able to push the throttle lightly going up a hill at 47 mph in 4th (OD) lockup without the lockup TC cycling. The Diablo Puck even has the power to accelerate at 1150 RPM on the tach. The stock truck always went to 3rd gear with the "stock power" on the same hills but lockup cycling every 5 seconds was ridiculous. Between the Puck providing torque so it sticks in same gear on hills and the TC lockup staying locked I am sure I have 50% less wear on the tranny.

Hey guys I believe I am the person Michael is talking about when he created this Thread... Seeing as how I replaced both batt. new alt., new apps sensor... took it to best diesel shop in town and they tin foiled the wires and added a new ground wire to the apps sensor...still having the same 4th gear hunt and loping at idle... took it to shop 4 or 5 times and they kept throwing parts at it till they finial said "we dont know whats wrong with it, you can keep throwing money at it and eventually replace the computer"... talked to Michael on phone one day and he suggested pulling alt. fuse and run down the road and see how it acted...Wow no more problem!! so im living proof that the band aid stuff doesnt always work!.... did a voltage check and sure enough the ac voltage was thru the roof... so replaced the alt. agian and done great for bout a week then came back hard and strong!! every gear was doing the hunt..and ac voltage was high agian!...so i got to looking at the alt wires and seen where the green wire going in to the plug on the back of the alt. had small bare. I messaged Michael and asked him about it, I believe he said the green wire had something to do with the pcm so yes it could be putting out ac current..( correct me if im wrong Michael... just got off work and have had a couple of drinks) ...so I wrapped the wiring of the plug with electrical tape and bam problem fixed!!!...havent had any issues for a couple of weeks now...I have made videos of my problems and fixes so I am working with Michael to write a article up on it because ladies and gentlemen we have found the cure to the famous 4th gear hunt! and I owe a HUGE debt of graditude to Micheal Nelson for helping me figure out the problem... we have talked on the phone and messaged each other no telling how much! lol but he was patient with me and he figured the problem out!.........so agian thank you Michael!!

The newest in my lock-up issue's are now it lock/unlocks rapidly when its raining or wet out. I went to TSC the other day, it was dry out and the trans shifted perfect but when I came back outside it was raining really hard. The roads were flooded and the truck was locking/unlocking rapidly, like twice a second. Now even after it quits raining its still doing it so im gonna pull the alternator fuse and take it for a drive. Will report back shortly.

- - - Updated - - -

No go, pulled fuse and still shifting.

Waiting for the reply...

It didnt change anything, still shifting crazy. I cleaned the battery terminals for my monthly cleaning and will take a run in a few minutes.

Hey.... Have you looked at your plugin and wires on back of alt?.... That was my problem... Try unplugin it and plug it back in. Had bare spot on wire .... Tiny tiny spot.... Also how far did you drive?... Mine wouldn't stop acting up till voltage gauge went down and check gauges light came on....

Cleaned terminals and resset apps and it drives as it should.

Well best of luck with it Ryan... I really don't think u fixed problem just delayed it for a bit... Mine would come and go and the reset never worked for me.. So I replaced apps sensor and still had the problem .... I got some videos I am gonna post soon as I get time :banghead:....so that way ppl can see if I was having the same problem as they are...

my truck is the same lock/unlock ,tried different things no luck,next I'll check the alt wiring,if I don't use my truck for 4/5 days or more,when I put it in drive the truck doesn't move for a few seconds .Is that related to the lock/unlock of the torq convertor?

- - - Updated - - -

Never tried pulling the fuse for the alternator,where's the location

Regarding the diode problem with the alternator--is there a good way to check this? I'm assuming you would have to have the alternator apart? I vaguely remember doing this on a bosch diode board on an old BMW motorcycle, but haven't found anything specific to the one on the Dodge.Second, any easy way to buy a replacement rectifier or diode assembly? I'm sure I can get one once I've got the alternator out and apart, I can get the appropriate part from any place that sells rebuild parts for alternators, but I'd like to have the most likely parts in my hand when I start taking things apart. Geno's Garage sells a Gould kit to rebuild the Bosch alternator, but it's only the bearing and brushes.I've been planning on replacing the belt, idler pulley, and putting brushes and bearings in the alternator as preventative maint anyway, so putting in a new rectifier would be a logical addition to that, especially if it will fix my hunting issue.Thanks for your good work on this issue.

Your DVM accuracy is rather low on AC it appears...

I went out and grabbed my 23 year old Fluke 75 DVM and re-tested on my Cummins...

Rest Voltage

Battery Volts AC ............. 0.001 VAC

Battery Volts DC ............. 12.62 VDC

Running Voltage

Battery Volts AC ............. 0.011 to 0.019 VAC

Battery Volts DC ............. 14.02 VDC (72*F outside temp)

0.100 Volts AC isn't a problem really... It when you see 14-28 VAC on the DVM.

Mike, hate to throw a monkey wrench........ my trucks got no hunting but my DVM is showing 30.1 VAC

Could this have anything to do with the PO 0216 showing up? Low fuel pressure from low voltage to the pump?.

I noticed that on my truck I had to wait until the grid heaters stopped cycling as DC voltage goes from 13.8 VDC (off) to 10.5 VDC (on) and the DVM picks this up as AC. Does not account for the 30 VAC you are getting though?

my truck is the same lock/unlock ,tried different things no luck,next I'll check the alt wiring,if I don't use my truck for 4/5 days or more,when I put it in drive the truck doesn't move for a few seconds .Is that related to the lock/unlock of the torq convertor?

- - - Updated - - -

Never tried pulling the fuse for the alternator,where's the location

Its under the black cover behind the driver side battery. It will be at the end of the 2 wires (+/-) coming into the box, you will have to remove two screws and pull out the fuse.

Regarding the diode problem with the alternator--is there a good way to check this? I'm assuming you would have to have the alternator apart? I vaguely remember doing this on a bosch diode board on an old BMW motorcycle, but haven't found anything specific to the one on the Dodge. Second, any easy way to buy a replacement rectifier or diode assembly? I'm sure I can get one once I've got the alternator out and apart, I can get the appropriate part from any place that sells rebuild parts for alternators, but I'd like to have the most likely parts in my hand when I start taking things apart. Geno's Garage sells a Gould kit to rebuild the Bosch alternator, but it's only the bearing and brushes. I've been planning on replacing the belt, idler pulley, and putting brushes and bearings in the alternator as preventative maint anyway, so putting in a new rectifier would be a logical addition to that, especially if it will fix my hunting issue. Thanks for your good work on this issue.

The Bosch Alt. uses welded in diodes not like some were the diodes are bolted in. Also by the time the Bosch alt. wears out a set of brushes typically it needs new slip rings as well which needs to be pressed on and also welded.

Regarding the diode problem with the alternator--is there a good way to check this? I'm assuming you would have to have the alternator apart? I vaguely remember doing this on a bosch diode board on an old BMW motorcycle, but haven't found anything specific to the one on the Dodge. Second, any easy way to buy a replacement rectifier or diode assembly? I'm sure I can get one once I've got the alternator out and apart, I can get the appropriate part from any place that sells rebuild parts for alternators, but I'd like to have the most likely parts in my hand when I start taking things apart. Geno's Garage sells a Gould kit to rebuild the Bosch alternator, but it's only the bearing and brushes. I've been planning on replacing the belt, idler pulley, and putting brushes and bearings in the alternator as preventative maint anyway, so putting in a new rectifier would be a logical addition to that, especially if it will fix my hunting issue. Thanks for your good work on this issue.

I know there is a supplier for diode and can be replaced but which vendor I'm not sure...

Mike, hate to throw a monkey wrench........ my trucks got no hunting but my DVM is showing 30.1 VAC Could this have anything to do with the PO 0216 showing up? Low fuel pressure from low voltage to the pump?.

What I'm finding out now is some Digital Volt Meter are just plain poor for measuring AC voltage and tend to wonder all over the map. Like I've got $130 Fluke 75 Digital Volt Meter which is over 25 years old. But the accuracy is top notch. Where a cheap hardware store DVM might produce some poor readings.

I noticed that on my truck I had to wait until the grid heaters stopped cycling as DC voltage goes from 13.8 VDC (off) to 10.5 VDC (on) and the DVM picks this up as AC. Does not account for the 30 VAC you are getting though?

Other than the 30 VAC showing up, my trucks' showing the same charging numbers.