Bus won't start....B500 suspected fault

[John316]

So here is the scoop. We went to start this evening, and it wouldn't turn over. Looked around our shift pad was dead. No lights, nothing. We also have a retarder applied light on the dash.

I am guessing a sensor somewhere is at fault. I tried unplugging the tranny computer, and I also checked the fuses. No joy.

I don't even have a code to give you all, because our keypad is down. No lights.

Any advice? Tranny is just about brand new.

[luvrbus]

John, do you have anyway to check circuit 123 from the ECU when in neutral it's probably just a neutral starting relay you are getting no communication between the ECU and the shift pad refer to code 23xx for troubleshooting if you have a manual 

good luck

[John316]

Clifford,

I tried giving you a call on your cell. It is probably something really simple, but still has me stumped. Would you mind giving me a quick holler?

Thanks,

John

[TomC]

Ahh-the funness of electronics.

[Dave5Cs]

Is there any change today John.Did you find the problem.

Dave5Cs from Galaxy S III

[luvrbus]

He is up and running

[John316]

It turns out it was a fuse.

For the archives....

We had a dead shift panel on our Allison B500 transmission. The retarder applied light was also on. I checked the fuses in the battery compartment, and they were all good (that is where the main ATEC fuses and ECM fuses are located). I rebooted the ATEC, no go. I checked all sensors and connectors on the tranny, no joy. I checked the connector on the back of the shift pad, all good, but still no joy.

I knew there had to be something else, and it had to be simple. Sure enough, in the front junction box, far left corner, very bottom of the box, is a fuse. That is where power for the keypad goes through. That fuse was blown. I replaced it, and we were set.

It took me two hours to find a REALLY simple fix. At least we got it.

And thanks to Clifford for calling. I am sure that I found that fuse, because he called. I was on the phone with someone else, when his number appeared on my phone. Almost at the exact same time, I found the fuse. Figured it had to be because he left me a voice mail is why I found it

Cheers,

John

[belfert]

Glad it was a simple fix.  My generator quit producing power on Saturday.  I thought the worst at first, but simple troubleshooting showed an issue with the brushes.  Sure enough, disassembled the generator and the spade connector had come off the brush assembly.  Simple no cost problem, but it cost me six hours of time.  Coincidentally, my generator battery died during this whole thing and I had to install a new battery as the other one was really old (10 years it appears).