speedometer & doorlocks & overhead mileage display quit working
 

2000 3500 4x4 any suggestions?

Gotta be a fuse? Is it the entire guage cluster or just the speedo?

spedo not working
 

computer or sensor ? auto trans , tach still works .any ideas???:humm::humm::humm:

Damn, I was looking through my service manual, and that's a very odd combination of things to fail. What were the events leading up to this failure? Speed is sensed at the diff, door locks on their own circuit, and the overhead is a BUS communication system to the PCM, i believe. I'll keep looking, in the mean time checking ALL fuses, circuit breakers, and relays would be an excellent idea. Even switching them around with others.

door locks still work with the switches,but the automatic door locks dont.they used to lock at 10 - 20 mph

Hey, The overhead console not working is a fuse, IOD or something like that, in the cab, in between the drivers door and dash ( where they mate up )

The door locks would be a setting in the PCM, have to have the dealer do it, and they'll prolly charge you if you don't take it to the dealer often.

And speedo... not sure.. maybe it's got a VSS issue'

it would stop working and then start again for a month or two, it seems as if it all is tied into the speedo somehow.:humm:

i giggled a little bit there,

It is indeed tied into the speedo, If the speedo isn't working, the truck isn't seeing any movement, hince not gonna lock the doors,

what makes the speedo work or not work

Broken wire to the speed sensor, or the speed sensor it's self:

"Vehicle speed and distance covered are measured by
the Rear Wheel Speed Sensor. The sensor is mounted
to the rear axle. A signal is sent from this sensor to the
Controller Antilock Brake (CAB) computer. A signal is
then sent from the CAB to the Powertrain Control
Module (PCM) to determine vehicle speed and distance
covered."

According to my manual, the speed sensor runs into the PCM at pins 25 and 28 on the C2 connector. I would assume that it is the middle of the 3 connectors. Check for continuity between the plug for the sensor, and the plug at the PCM.