Bobcat BOSS unit not displaying metrics properly 1993 753

[zanecr]

Hello,

1993 bobcat 753 boss unit not displaying metrics properly.. This bobcat has been an ongoing project, so I have been putting off messing with the boss unit. The first issue was that it was displaying a EP-3 code, oil pressure sensor wiring not connected, which it was.

I hadn't dove into fix that issue yet but, one day I welded in a new section of metal for the seat in the cab as the old one was rotted out. my grounding clamp was right next to my weld, and battery was disconnected.. After welding, the machine no longer beeped at me and does not display the code anymore as well as the metrics being way off / missing now. My guess is something was messed up when welding? The machine still runs as it did before the boss unit started acting up.

I have checked all the connections and cleaned them, as well as grounds. I have 12v for the backlight pin and 5v at the orange wire going to the LCD.

Attached is a picture of what is shown when the machine is running.

 

[HarleyHappy]

It kinda looks like the machine is giving you a thumbs up for the welding. lol
With a Tener for score.

 

[zanecr]

It kinda looks like the machine is giving you a thumbs up for the welding. lol
With a Tener for score.

I was very conscious of the possibility of something like that happening and attempted to research if anything would go wrong! the consensus was it would be okay.. And now we're here!

 

[HarleyHappy]

Welding shouldn’t have damaged it if the battery was disconnected but I have seen some weird effects. Is there a way to reset the ECM.
Recently I welded on a Chevy truck with the battery disconnected and when hooking back up, somehow I hit the ground on the sidewall and it wouldn’t start.
The fuel pump wasn’t working properly and my brother an excellent GM tech came over and plugged his scan tool in and it took him a bit but for some reason that little arc screwed up the ECM and it had to be completely shut down and restarted.

 

[Welder Dave]

On new semi's and even on my old plow/dump truck with electronics they caution to disconnect both battery cables. In the case of new semi's to also disconnect the ECM. Hopefully it can be reset.

 

[KyMadMan]

Hello,

1993 bobcat 753 boss unit not displaying metrics properly.. This bobcat has been an ongoing project, so I have been putting off messing with the boss unit. The first issue was that it was displaying a EP-3 code, oil pressure sensor wiring not connected, which it was.

I hadn't dove into fix that issue yet but, one day I welded in a new section of metal for the seat in the cab as the old one was rotted out. my grounding clamp was right next to my weld, and battery was disconnected.. After welding, the machine no longer beeped at me and does not display the code anymore as well as the metrics being way off / missing now. My guess is something was messed up when welding? The machine still runs as it did before the boss unit started acting up.

I have checked all the connections and cleaned them, as well as grounds. I have 12v for the backlight pin and 5v at the orange wire going to the LCD.

Attached is a picture of what is shown when the machine is running.
View attachment 328905View attachment 328906

Do you have any documentation that explains all the icons? I have the same system and while most of them are obvious, some are not. I'm getting a strange code that apparently is not a code on mine.

 

[zanecr]

Do you have any documentation that explains all the icons? I have the same system and while most of them are obvious, some are not. I'm getting a strange code that apparently is not a code on mine.

 

[KyMadMan]

Those are various codes. I have that in my service manual. I'm looking for what some of the lit and unlit icons on the read out mean. Oil, Temp, etc are easy enough. The triangle and other icons I have no clue and I don't have an operation/maintenance manual with would name the various icons. Thanks though Zanecr!

 

[Markle]

There are some BOSS manuals on eBay now.