I bought a brand new Super Pro 3" tach from a guy on Craigslist for $15 last week.
No cut wires, or tampering, but it does have a small external scratch from storage.
So here I am. I took the tach apart and switched it for 6 cylinder engines. I spliced the GREEN WIRE into what I believe is Pin 48 on the passenger side firewall for my '97 4.0L w/ the 5R55E. It was BROWN w/ YELLOW stripe, and I never saw a TAN w/ YELLOW stripe in the cluster. I roughly tested all the wires in the engine bay to get the tach to work, but it just vibrated above the 0 (almost 50-100 rpms). I hit the throttle and the needle only jumps up to ~ 900 rpms (normally ~4500 rpms).
WHAT IS THE PROBLEM?
I have tried to figure this one out, but can't figure it out. The power is correct, the ground is secured, and the only thing I can guess is the green signal.
I think it may be different as I have 3 coils instead of 1. Where can I hook up my tach signal in the dash or wherever there is a combined EDIS?
Thanks for everyone's help in advance,