Another problem with UB3..

[cs-x]

Ok.. I have rewired for the UB3, and it works great, but I have a new problem.. I didn't put in C13 until the other day, and I ran it to the orange wire on the ALDL. It's now connected. I can put one lead of a voltmeter in the ALDL and the other on C13 in the plug and I get continuity, but the tach refuses to work. To prove that I did it right, it did work about 3 hours after I installed it, but only for 5 mins. then it got stuck at 2950 rpm and stayed there until I restarted the car. Even the DIC was working for this short period of time. But neither have worked since. I've disconnected the DIC thinking maybe I got a bad one, but that wasn't the problem. Then I replaced the UB3 since I have 2 thinking that might be it.. nothing. Can somebody please tell me what I should look at now? I'm completely stumped