My First Post here..hope it's not too long.
I got a 96 GT with t-45. I swapped gears to 3.73 and bought a speedcal to fix the speedo. Install went well and it worked fine until you hit 55 mph where the speedometer goes to zero. I found the alternate bank 2 dip switch setting of "0100000" and that helped a little and makes the speedo go weird at 65 mph. The red LED light stays lit when the speedo goes haywire and I data logged to find that the PCM also gets a good speed signal.
I later found that my GPS head unit taps into the VSS wire as well and when I disconnected it, everything was fine. I payed a lot of money for the head unit and would like the GPS functionality so my question is. Is there a different location to tap my GPS (or speedcal) into? I've already tried the tail shaft speed sensor, the input wires before the speedcal, and the cruise control.
I've had my center console open with all the wires hanging out for 2 weeks now trying to resolve this issue so any input would be appreciated. Thanks guys.