Transmission control panel is blank...can't crank anymore

[fbitz777]

Things were working great except I had a low 12V battery but I managed to jump and get truck running. However I noticed the transmission panel was blinking and flaky.
I put new battery in an now I do not see any light on the transmission panel. I checked every fuse and relay and I noticed the crank disable fuse was clicking.

How do I check the power to that transmission panel or is it just dead?...from what I read unless it send a signal that it is in "N" I will not be able to crank the engine?

it's 1996 with Allison Transmission.

 

[GeneralDisorder]

The transmission control modules are very sensitive to battery and voltage problems. The older one's in those A0 trucks more so than the newer ones. Check the fuses and relays that feed the module power, and you can check for power at the module connector (refer to diagrams in the TM's section of the forum). Definitely remove the batteries from the truck, fully charge them, and reinstall. You can try power cycling the module by pulling the fuse out and putting it back in, etc. Just had the same thing happen on a HEMTT tanker with the WTEC II. Low batteries even after being on a charger for 2 days - powered it up and the Trans control was flashing. Was able to attach a slave cable from another truck and after pulling the fuse (conveniently located right next to the shift panel - gee I wonder why ) and reinstalling it the trans control came back online and unlocked the starter.

If the display is dark though - chances are the control is smoked. You may be able to send it to this place in TX.

Transmission Instruments

Those early WTEC-II boxes have the entire control module under the button panel and any cab turret leaks, etc can result in water getting inside them also. Piss poor design. The later trucks have the control module under the PDP and the buttons are a small remote panel so not nearly as exposed. The WTEC-IV and WTEC-V are also more reliable in general.

 

[MatthewWBailey]

Mine A1 did the same thing after my starter mishap. Batts were wiped out and the gear selector was dark even with ignition powered on. Came back on after the starter replacement and fresh batts. Had codes once it came back up.

 

[Ronmar]

1. You must have 12 and 24 at the test points when everything is turned on.
2. You must have a transmission display To provide the neutral start contacts. CB 79 and CB22 provide 24 and12v power to the transmission. There are also two additional red 10A fuses in the VIM mounted under the passenger dash…

 

[fbitz777]

The transmission control modules are very sensitive to battery and voltage problems. The older one's in those A0 trucks more so than the newer ones. Check the fuses and relays that feed the module power, and you can check for power at the module connector (refer to diagrams in the TM's section of the forum). Definitely remove the batteries from the truck, fully charge them, and reinstall. You can try power cycling the module by pulling the fuse out and putting it back in, etc. Just had the same thing happen on a HEMTT tanker with the WTEC II. Low batteries even after being on a charger for 2 days - powered it up and the Trans control was flashing. Was able to attach a slave cable from another truck and after pulling the fuse (conveniently located right next to the shift panel - gee I wonder why ) and reinstalling it the trans control came back online and unlocked the starter.

If the display is dark though - chances are the control is smoked. You may be able to send it to this place in TX.

Transmission Instruments

Those early WTEC-II boxes have the entire control module under the button panel and any cab turret leaks, etc can result in water getting inside them also. Piss poor design. The later trucks have the control module under the PDP and the buttons are a small remote panel so not nearly as exposed. The WTEC-IV and WTEC-V are also more reliable in general.

I definitely have a WTEC II and took it out; will now check to power to the connectors
So the truck is a 1996 but the part is 2007; must have been serviced before. Not cheap if I google it or Ebay so I am hoping the link you provided above will be cheaper.

 

[leibuys]

We were having similar issues, traced it back to the VIM due to no power at the TCM. somehow water got into the VIM. currently looking for a replacement VIM. Any suggestions where to find?

 

[Ronmar]

We were having similar issues, traced it back to the VIM due to no power at the TCM. somehow water got into the VIM. currently looking for a replacement VIM. Any suggestions where to find?

Thats weird, the VIM is perhaps the most waterproof box on the A0... I have one, as i deleted mine, all you will need are some relays for it... message me.