Ground wires in battery connected to Positive post

[2000 Damon]

I am currently purchasing a 2000 Damon Escaper fixer upper. The owner passed away so finding the faults with the coach is up to me. MY biggest problem is the warning lights for the Transmission temp. transmission do not shift, check engine, stop engine lights and warning alarm are all on. I belive it happened from one of the cables on the motor batteries was connected to power. The cable that was connected to one of the positive terminals was a ground cable that had 8 ground wires in it. Charles at Spartan helped me find that problem. All the gauges monitoring the transmission and the motor temps all read fine and a computer check of the transmission and motor functions are all good with no fails except for a 6942 fail code on the tranny which is probably a bad tranny ECU. Does any one have any ideas on why the fail lights are still on? All of the fail lights require a ground for each light to come on. The technician that checked my motor and tranny said nothing is wrong with the motor (8.3 L Cummins ISC 300 HP) and he said I might be able to flash my tranny ECU or I would have to replace it. He also stated that wasn't causing my fail lights. He also said that if the stop engine light was for real it would shut down the motor automatically. Oh and while I'm on the subject about not knowing nothing about my coach, the chassis battery box had all the wires corroded loose and after I replaced all the batteries and cables I noticed one wire comming in from the side of the panel in the battery box near the coach to motor batteries solenoid, this wire is the only wire in the chassis battery box that isn't connected straight to ground or the power side of the solenoid. I assume It goes to the positive terminal but am not sure. It's about a size 14 wire, encased in flexible plastic protective tubing. Help !!

Thanks 2000 Damon Escaper 3980 with a 8.3 L ISC cumins diesel, Allison 3060 transmission on a Spartan chassis

[gasser 38]

Dont know about wire in battery box but if the ecu is no good it could be throwing all those lights on

[wa8yxm]

I agree with Gasser 38 that if the grounds were made hot by mistake it might have fried your comptuer..... (Unless ALL it's grounds became hot)

Computers generally do not like reverse polarity much.

Also, there are 3 kinds of error codes.

Soft, firm and hard

Soft codes (What I'm calling soft codes) go away when you re-start the car. Simply turning the key off and re-starting is all that's needed.

Firm codes, do not go away till they are reset with a reader, but when the problem is fixed the light goes out.

Hard codes. do not go away till someone resets the code with a code reader. and they keep the light on.

You need a code reader Likely not the 20 dollar kind.

[2000 Damon]

Thanks gasser and Wa8yxm. I had a cummins rep with a laptop reader clear all the codes and he couldn't clear the tranny 6942 ECU fail code. When the clear command was placed the tranny fail light on the dash would flash for a milisecond and be right back on. Is the ECU right below or part of the Allison push button control panel? I have the Allison WTEC III control panel. It can also read the code errors and clear them. I tried that before I had the Cummins tech come out. But you guys may be right a flashed or rebuilt ECU may fix all the dash fail lights as well. I found a place on the internet that repairs ECU'S and guarantees their work. Their cost is about $ 565 with shipping. Their based out of Florida. The local technician here said they could attempt the flash for $ 200. But if that fails I will still have to send it away and pay the $ 565. I'M kind of leaning toward skipping the flash because during the repair process they go over everything, clean everything up and guarantee it. I was in electronics for years and your right most circuits aren't built with reverse polarity protection. I feel fortunate that the cummins ECM wasn't fried and other things that were connected to the eight ground wires.

[98DAMON330]

try a used tranny comp.or see if there is a fuse to the trans ecm that is blown but if your getting other return codes.check for tranny t s bs and maybe there was an issue that year.