Tac Wiring Problem

[ccope]

Tac wiring issue I need assistance with. All other gauges are operable i.e., speedo, fuel, temp, oil pressure. I realize the tac has a separate wire(s) than the cluster harness but with all others working it surely is grounded. Two wires coming from back of tac, brown and red. Red is in ignition (hot) and brown is through firewall to HEI distributer. 71 chevrolet, 383 stroker with a AAR wiring harness built to specs. When I plug in the brown wire to the to the distributer it completely kills the engine. Unplug it and all is good. I have a yellow wire attached to the furtherest connection on the starter solenoid and a purple wire on the most inside connection (nearest engine) and the hot wire of course in the middle that runs to the positive side of the battery. The yellow and purple run back into the wiring harness, up the firewall and then split out to the distributer where a pink wire is plugged into the distributer and reads 14.4 volts. There is a dark blue wire with an odd end connector that I have no clue about. Any assistance would be surely appreciated. Pics would be valuable.

Thanks,

Sorry, I don't have a photobucket set up yet so I have no available pics to post. I will get to this at some point.