Tranny lunges in gear/odd shifts 40mph max

[Mopar1973Man]

Nope. Just install see if it shifts better.

[CDeGolier2001]

Truck is still down,I've traced tranny wire from harness to tranny.all in good shape no cuts or knicks. But when I unplugged main tranny plug the truck stopped wanting to jump into gear? 

[pepsi71ocean]

Question, when you swapped out the bodies did you also swap over your wiring?

 

I would put your truck into manual 1 and see how it accelerates, I'm thinking your limp mode because it doesn't like the wiring.

[CDeGolier2001]

I used all my original cummins wiring 

[pepsi71ocean]

17 hours ago, CDeGolier2001 said:

Truck is still down,I've traced tranny wire from harness to tranny.all in good shape no cuts or knicks. But when I unplugged main tranny plug the truck stopped wanting to jump into gear? 

Can you expand on this? 

 

Usually pulling the trans plug will force the valve body to run without electronics, so you should have 1-3.

 

If your live pressure is to high you will start in 2nd gear which will cause a dragging feeling.

 

Did you try to stay the truck in manual 1 position and see if it drives better, you'd have to shift to manual 2 when you hit ~15mph.

[CDeGolier2001]

I will try manually shifting today and report back,I believe it didn't shift at all out of first when I unplugged tranny plug

[pepsi71ocean]

Have you looked at this article? 

 

 

[CDeGolier2001]

I checked and I have 14 volts at the wire? Bad alternator?

[pepsi71ocean]

On 10/9/2018 at 10:10 AM, CDeGolier2001 said:

I checked and I have 14 volts at the wire? Bad alternator?

Which wire are you speaking of?

 

The alternator can produce between 13.4 and 14.8v DC normally when commanded by the PCM.

 

But the AC sign wave is what is of concern. Have you attempted to drive there truck with the alternator un hooked?

[CDeGolier2001]

I have and it didn't change anything,and I guess I was checking the orange black stripe wire

[pepsi71ocean]

On 10/10/2018 at 12:14 PM, CDeGolier2001 said:

I have and it didn't change anything,and I guess I was checking the orange black stripe wire

I believe that should be 5v correct @Mopar1973Man

[CDeGolier2001]

The wire I checked also had tap on it for tq locker. Is this the right wire that should have 5v?

[Mopar1973Man]

That should be +12V.

 

RED wire is the power from the transmission relay. The PCM only ground or open the Orange/Black lead.

 

Edited October 12, 2018 by Mopar1973Man

[CDeGolier2001]

I have 14v at the orange/tq lock wire is that proper?

[Mopar1973Man]

1 hour ago, CDeGolier2001 said:

I have 14v at the orange/tq lock wire is that proper?

 

Yes. That is normal. That means the power from the Transmission relay is reaching the solenoid and the orange black is open currently. Again the only thing the PCM does is control the time at which the orange/black will ground which will lock up the torque converter. Then if it opens that connection then unlock the torque converter. As you see the alternator field wire (blue) which is the key on sense for the transmission relay to send power to the transmission.