47re problems

[Finlandese]

I'm having torque convertor locking/unlockin problems. It happens between 40-55mph. At first unlocking was very fast, maybe one second. Next day unlocking lasted couple of second at time. I know something about ac noise, can it really cause that or is there something else wrong?? Any ideas where to start?? Brake light switch, output shaft speed sensor?? Thanks in advance!

[Me78569]

Ac noise and the wt ground mod pinned at the top of the section

[Finlandese]

I wish I understand english better!! But if I understand it right, I have to modifye cables from alternator to battery??

[Mopar1973Man]

 

[Finlandese]

That clears a lot!! Thank you!! Couple of questions though...cable from alternator to pdc should be taken out and moved from alternator to passenger side battery?? And ground cable needs to be cutted from splice and put 4 wires together?? Where do I bolt those 4 wires??

[JAG1]

You are understanding what to do well enough. Those 4 smaller sensor wires get grounded together on the back of the front gear case just below the VP44 and a little toward the driver side, there is a factory threaded hole there to use. I cannot remember the size, but found two bolts I needed by trying different sizes from my bolt bin.

[Finlandese]

And cable from alternator is attached to passenger side battery instead of pdc?? And circuit breaker to that cable?? What do I do with the old ground cable what was taken off?? Sorry all these questions, takes time to understand all instructions eventhoungh I have studied english many years

[Mopar1973Man]

Yep... Alternator is moved to the passenger side and the ECM and VP44 ground moves to the driver side plus the gear case.

[Finlandese]

Would 200 amps circuit breaker be too big for the alternator cable???

[Mopar1973Man]

The circuit breaker is only just in case the alternator diodes short to ground if so to prevent the wire from glowing and igniting a fire under the hood. So the breaker should be big enough for maximum charge amperage and cut the battery loose if it happens to short to ground.

[Dieselfuture]

5 hours ago, Mopar1973Man said:

The circuit breaker is only just in case the alternator diodes short to ground if so to prevent the wire from glowing and igniting a fire under the hood. So the breaker should be big enough for maximum charge amperage and cut the battery loose if it happens to short to ground.

What was the other short that takes PCM out, I keep mixing the two

[kzimmer]

6 minutes ago, Dieselfuture said:

What was the other short that takes PCM out, I keep mixing the two

 

The alternator field winding leads. I think this is a very rare failure, but since it happened to @Mopar1973Man it's apparently possible.

[Finlandese]

Today I did the ground mod. Didn't move alternator cable, only the ground cables. Just came back from test drive and guess what....no more unlocking!!! So, thank you very much to you all who helped me to understand how to do it!! I would recommend this site to every Dodge owner here in Finland!!

[Finlandese]

I did it again last night when I was driving to work!! But just twice! Today I scanned the obd codes and there was P0122 and P1693 codes. Could the unlocking problem be from APPS???

[dripley]

You ought to move the the charge wire to the passanger battery and get it away from the other wiring. 

[kzimmer]

8 hours ago, dripley said:

You ought to move the the charge wire to the passanger battery and get it away from the other wiring. 

 

I gotta ask, why do people feel this is so important? Definitely not trying to be ignorant here, no disrespect. I'm just asking as a professional in the field of electronics and electrical. And I love a good debate, haha.

[JAG1]

Because the biggest offender of AC ripple comes from the alternator B+ charge wire so you don't want to send it right into sensors and PCM/ ECM at the distribution panel, you want to give the batteries the job of filtering out all that AC noise first before going on to your sensitive electronics. You want a clean DC current which the batteries are able to. 

[dripley]

I would debate it but it would be a pretty short debate with my limited knowledge of electricity. @W-T, the man that wrote the mod would be better suited for the debate. But what @JAG1 states above is what I remember from his article. It did work on mine as far as lowering the ac noise.

[kzimmer]

34 minutes ago, JAG1 said:

Because the biggest offender of AC ripple comes from the alternator B+ charge wire so you don't want to send it right into sensors and PCM/ ECM at the distribution panel, you want to give the batteries the job of filtering out all that AC noise first before going on to your sensitive electronics. You want a clean DC current which the batteries are able to. 

 

But why not just fix the source of the AC noise? I thought the offender of the AC noise issue was open alternator diodes. You can move the charge wire, but electrically it's still connected to the same node that it used to be. Just instead of being 2 feet away from the fuse box, now it's 5 feet away from the fuse box. It's essentially the same connection it used to be, with some length of copper in between.

 

Maybe having the point of contact closer to the battery does help filter a little, but I just can't see it being a major mediation of substantial AC ripple. Even a perfectly working alternator will have some ripple; that's the nature of any diode based rectifier.  Did you know AC ripple can present itself across a bad cell / battery in a multi battery configuration? Ideally, DC filter capacitor would be the best solution to cut down the ripple on any 3 phase full wave rectifier. However, that's potentially another maintenance item. 

17 minutes ago, dripley said:

It did work on mine as far as lowering the ac noise.

 

Was it moving the charge wire that helped, or fixing the deficient grounds?

 

Sorry for the derail @Finlandese. The skeptic in me must know the truth!

Edited March 22, 2019 by kzimmer
Typo

[dripley]

10 minutes ago, kzimmer said:

 

Was it moving the charge wire that helped, or fixing the deficient grounds?

I did it all and then checked the voltage. So no testing in between. Have you read the article?