Also make sure the drain on the heater box is clear. It comes out near the trans dipstick, low on the firewall.

Smack the top of the dash again, maybe the tach will fix itself. On mine the dash lights sometime would not light up. I took it apart several times, traced the wires, checked the pins and could not find any issues. I just dealt with it and for the once in awhile just smacked the top of the dash.


Outcast Dodge guy.