I changed the 6.8 engine (it locked up) and ever since the speedometer and votage gauge in the instument cluster have not worked.
I have 2 of the factory manuals, but not the electrical wiring manual( I thought it would be in there.
Any help would be appreciated

 

Did you happen to change the engine computer during this repair?

Was this a direct replacement job with a identical junkyard or re-manufactured engine?

 

No computer change. The engine is a ford reman.

 

Check all the fuses under the hood and under the dash.

Is the abs light on and does the cruise control work? If not, and the speedo doesn't work either, it may be something wrong with the speed sensor, possibly a fuse that powers some part of it's circuit.