Gawd I had one, it seems so long ago...I had some initial troubles with mine as the wiring in a 40 Mopar still sucks plus the added 40 years of abuse.

Generally, if I remember, I had to run dedicated wires for the direct connection for power and ground. Everything in the vehicle is useless. Also had a lot of trouble finding a good keyed 12v wire.....An MSD system can muddy up the signal as well....keep it away from that.

'70 Cuda,...605 EFI Hemi Street Car (6.20 best pass, 1.33 60ft)
https://www.youtube.com/watch?v=WYw6RA-k5Bk (6.25 at 108.75mph from inside car)
https://www.youtube.com/watch?v=3zQEb9uxFng (6.25 at 108mph from outside car)
https://www.youtube.com/watch?v=JCvfzsC4NgM (9.9)

'66 Barracuda AWB Stretched nose Blown 440 Car in build stage

'71 Duster Drag Car 400 Low Deck 512 best 6.002 at 115.44mph
https://www.youtube.com/watch?v=Znuo3jMUXTk