I’m trying to help my father in law with his 1999 ram 3500 Cummins, I’m not experienced with dodges. The truck runs fine but the ABS and “brake” lights have been on for a year or so. Recently it developed a new issue. While driving, the speedometer quits working, followed by the tach, the all the rest of the gauges quit including the odometer and a bunch of lights come on like. CEL, WIF, low fuel, etc. the first time it happened, he shut the truck of and checked everything, found nothing wrong and it started right back up with all gauges working. Now it will randomly happen and if you keep driving, the gauges will all come back on at once and be fine until it decides to do the same thing all over again. The order of gauges dying is consistent. I found out how to get the gauge cluster codes and I got 900, 920, 921, 940, 950, 999, then ran a self diagnostic which came up with “no bus.” Where do we go from here? TIA

 

No Bus means it lost communication with the computer system. Could be bad wiring, bad computer, or a bad sensor.

 

What sensors could be affecting this?

 

Any of them on the 5 volt bus. Usual culprits are rear O2 sensors. Basically, you need to start unplugging sensors, until the issue goes away, the last one you unplug is quite likely the culprit.

 

Also don't buy into the online people and mechanics saying it's a fuel pump that causes that. It is not

 

Mopar - no, I don’t believe it is. Haha

 

HeyYou - is there a wiring diagram that shows everything on the 5V bus?

 

Download the FSM from the FAQ section it will show everything on the 5V reference

 

Yep, get a service manual here.

 

Thanks I don't have the link