Fordvette

As the title says, I have swapped out the Dummy lights cluster for a tach and intrusment .. but when I turn on the headlight dimmer the tack, oil and battery go dead. Ive been trying for almost a day to trace a bad ground and no luck. Swapped out steering column cause I added a Tilt, Swapped out the cluster, just to be safe it wasnt the printed circut board, Head light switch.. etc etc..

I was under the assumption this was a direct swap and play.. untill I looked closer in my Tech manual. The pin out are slightly different for a cluster and dummy ..

Ive searched third gen and google to no avail, either I am alone, or this is a wierd problem

See attached for the difference in pin outs Ive found, the top one, is a Camaro listing in my book, the bottom is a berly. ??

Pin 1 is different and pin 6