Dodge Repair Questions? Ask a Mechanic for Answers ASAP
The speedometer is part of the cluster, which is a computerized module in it of itself. The cluster will position the speedometer needle based on speed signals it gets from the body control module through the CAN network.
What is it you're trying to diagnose?
Well, that's what I'm trying to explain; there is no speed signal wire going to the speedometer head on a 2008 Ram 1500. The speed signal comes from sensors in the wheels and transmission to the anti-lock brake module. From there it goes to the body control module where it is processed and sent to the instrument cluster. It is all done from module to module through the CAN network using serial data.
In addition, all modules in a vehicle are programmed to that vehicle's VIN. None will work on any other vehicle unless they're reprogrammed to that other vehicle's VIN.
I'm sorry if that's not what you wanted to hear. Please don't shoot the messenger :-(
Thank you for understanding my position.
Let me know if there is anything else I can do to help.