Got a 2000 TA in my garage that I'm tuning. The owner did a t56 swap, the car originally had a 4l60. The tach doesn't work at all and I can't figure out why. Yes, it is tuned with a M6 file, before anyone asks. I'm wondering if there isn't a pinched/cut wire somewhere....just curious if anyone knew where else to check. Fixing it isn't in my scope of work but it's driving me nuts.