LMTV ECU Voltage Regulator location?

[Ronmar]

you can leave ground connected to the truck, but disconnect AND INSULATE the terminals on the 14, 28 and E terminal cables.

Connect one jumper cable lead from alt gnd terminal to - on your 24v test battery
connect a second jumper cable lead from the 14V alt terminal to the middle of your 24V battery(where the two batts are tied together).
connect a 3rd lead between the 28V alt terminal and the +24 terminal on your 24v battery.

once running and all the cables are good, use a small jumper from the alt 28v terminal to the E terminal on the regulator to bring the alt online then you can start measuring voltages...

 

[Chrispy23]

Having the same code as you! Just purchased a 99 m1079. When thrown into drive the truck bogs down / doesn’t want to accelerate. Will stay at about 5-10 mph until I’m about 50-60% pressed on the throttle for about 10-20 seconds. After that initial shift it drives perfect and shifts great, until comes to a stop and does it again. Curious if you are having any drivability issues in first gear from a stop.

Hey all, I've got a new to me 2001 m1078a1 that started throwing the D1323 code, voltage from ECU high, on the Trans.

So im trying to locate the ECU voltage regulator, part # 19207-12378784-001

Ive read as much as I could f on here and tried to dig into the service manual but I just cant seem to figure out where this part is located in/on the truck.

Any help greatly appreciated as I am scrambling to try and have this up and running for our towns 4th of July parade!

 

[Ronmar]

nevermind

 

[Chrispy23]

nevermind

it may be in not 100% the correct forum, but the same trans code made me curious if they are also experiencing the same issues as I am with the code. Or if other have experienced with this issue!

 

[Ronmar]

electrically controlled/electronic transmission, so the power system must be correct for proper operation.

clean all the connections between batts and power panel.
The grounds are trash on al these vehicles. Clean all the grounds... starter to drivers frame, alt to frame, cab to frame behind grill on passenger side, power panel to dash and dash to cab. Strip them to bare metal, throw the star washer in the trash, re-assemble with coppercote or dilectric silicone grease, then re-assemble. apply spray paint or galvcote over top of the assembled connection.

What batts are you running. the four 6t batts are too big for the 60/40 alt and regularly cause issues if they are not capable of being charged, or are not mostly charged(heavy alternator load).

then there are the alternator running voltages. should be 14.1/28.1... What are yours?

 

[Chrispy23]

electrically controlled/electronic transmission, so the power system must be correct for proper operation.

clean all the connections between batts and power panel.
The grounds are trash on al these vehicles. Clean all the grounds... starter to drivers frame, alt to frame, cab to frame behind grill on passenger side, power panel to dash and dash to cab. Strip them to bare metal, throw the star washer in the trash, re-assemble with coppercote or dilectric silicone grease, then re-assemble. apply spray paint or galvcote over top of the assembled connection.

What batts are you running. the four 6t batts are too big for the 60/40 alt and regularly cause issues if they are not capable of being charged, or are not mostly charged(heavy alternator load).

then there are the alternator running voltages. should be 14.1/28.1... What are yours?

cleaning all of the grounds is next on my to do list. The original batteries were shot, so I went with a brand new set of group 24 batteries. Only having driven it a few times, videos of it driving prior to me owning it it shifted great, and then once the new batteries were swapped in following the same wiring diagram the issue of struggling to shift out of first begin. As for if the transmission code existed prior, I am unsure as it was not checked

 

[Dexis]

That is different than my original issue. Mine really started acting up under higher speeds and engine load. First happened at highway speed and afterwards at 40+ for the most part. During that time it would operate fine at lower speeds, offroad on the property, 0-15mph-ish.

I still haven’t sorted this out but if i had to guess it sounds like we likely have a different set of issues manifesting that specific code.