Let's run this up the flag pole see if it fly's. CCD needs to opperate at a specific voltage on the + -. Many faults can interupt this voltage including the overhead. Are your new wire twisted together? Any othe issue's going on when the overhead is plugged in? Have you tried the cluster test by pressing the trip button and key on for a CCD code? The CCD voltage can be checked at the data link under the dash pin's 11-3. With the overhead unplugged and plugged in whats the volts not ohm's at those's pins? All this info is in the FSM aka FACTORY SERVICE MANUAL.

 

I have a 97 would one of those newer one that do the readings work? If i changed