Hello everyone I am having trouble trying to figure out why my speedo no longer wants to work. I have a 92 tbi auto car that was swapped with an ls1 4l60e. I have a stock style computer with a bp automotive harness. Directly after the swap was drivable the speedo did work for a while. I did not personally do any of the wiring for the motor had a more experienced person to it. Recently my speedo gives no reading and is just sitting bellow 0. Any tips to point me in the right direction. From what I can tell the 1 wire coming out of the pcm is directly spliced into the wire that feeds the gauges which is a brown wire I believe. Thanks for then help

 

take the output wire from the bp harness and put it to the correct pin on c207 , you may need to jump 2 pins on the buffer box plug.
https://berlinetta.info/C207.htm