I purchased a 1999 Dodge Ram 1500 4x4 extended cab used; it was partially parts-out but was assured it was roadworthy. The mileage noted on the title is 123,872 and again assured correct. The dash gauges/Speedo-odometer had been removed and I replaced them trying several others, but the odometer switches from the digital reading to "no bus" on it and the engine light flashes continuously after starting it for more than one minute. I have checked with some car dealers and they have told me there should be no problem changing this part. I would appreciate any help with this if possible.
You would need to have someone to put a factory quality scanner to check for a communication problem.
The no bus entered on the odometer is telling you there is no communication with the BUS network and the speedometer cluster.
The scanner will be able to determine if the problem is the speedometer cluster or a communication problem related to wiring or programming problems.
There is also a service bulletin that they have listed that is for a erratic operating speedometer cluster. The service bulletin number is 08-05-00 and is dated 4-21-2000, it tells about having to replace the sixteen wire connector for the speedometer.
Connect the DRB III® (factory scanner) to the 16-way Data Link Connector (DLC). Read and record all active and stored Airbag Control Module (ACM) Diagnostic Trouble Codes (DTC). If active and/or stored "No Cluster CCD Bus" DTC is present, perform the Repair Procedure listed in the service bulletin.
You can probably get the service bulletin form the dealer and they have the parts required parts and replacement procedure.
I've seen a similar problem on another Chrysler product, and all it required was a reboot. So you might want to try this before the TSB.
Simply disconnect the battery (both cables) and short the 2 cables together with a jumper wire or even a pair of vice grips. Then turn the ignition to "On" and let the truck sit for about thirty minutes. Then turn the ignition off, and reconnect the battery.
This procedure drains all the residual voltage out of capacitors. In this case, just like a PC, you're doing a hard reboot on the module within the instrument cluster.
No guarantee, but definitively worth a shot.