CAT 259D Backup Alarm Relay Current Above Normal

[Shorthorn628]

Hi all, first time poster looking for information to troubleshoot the error "144-6 Machine" "Backup Alarm Relay Current Above Normal" on my Uncle's Cat 259D S/N FTL01966 which has 1300 hours on the clock. In addition to the error message on the screen, the back alarm and lights don't work. Everything else appears normal. We have a small dairy farm in central NY and while I am usually pretty handy at fixing things I need help on this one. I have the owners manual and parts manual, but haven't been able to identify which fuse or relay controls that circuit or how it is routed. I also am not sure where the back up alarm itself is located on the machine. Now that the days are getting shorter, having lights sure would be handy. Any help would be appreciated, thank you!

 

[Nige]

Attached the troubleshooting procedure for 144-06 which contains a truncated electrical schematic with the relevant parts of the circuit for the backup alarm relay. You would probably be better off with a full schematic so keep an eye on your message invbox.

 

[Shorthorn628]

Awesome, thank you very much!

 

[Shorthorn628]

Well, with the engine running I pulled the backup alarm relay and the message disappeared, then 1627-6 "Fuel Pump Relay Current Above Normal" appeared. So I pulled that relay and both messages changed to "current below normal". I unplugged both the back up alarm and fuel pump from the harness and the error messages persisted, so my current hypothesis is there is a short somewhere in the harness.

I did notice that the fuel pump no longer made the ticking priming noise when turning the key to the on position. I had replaced it some time ago because the old pump failed. Hope to dive into it more tomorrow!

 

[Nige]

If you follow the procedure that I posted above step by step it will guide you to the root of the problem. the only condition is that the Diagnostic Code in question has to be Active when you start the procedure.

Have you checked the fuel/water separator for water recently.? Also have you inspected the condition of the inline screen that forms part of the fuel pump assembly.?

 

[Shorthorn628]

Just wanted to follow up, I raised the cab and immediately saw the wiring connector for the lower half of the fuse panel had a broken wire. I spliced it back together with solder and heat shrink tube and everything works as it should, including the priming pump. Thanks Nige for the schematic, I am sure I'll need to refer to it again in the future!