What wire for the Tach?

When I pulled the PI dash, the tach wire wasnt marked, after looking at the the wiring diagrahm for a cobra that the ECU cae out of i thought it was the orange/white wire coming from the ECU, but when I hook the tach up to that wire the fuel pump stays on(it buzzes constantly)

2 questions

1. what is the orange and white wire for? something was tapped in to it that said "user 2" and it went into the ECU. and into the PI dash(which should be the rpm tach wire.

2. what wire do I need to tap in the ECU, they had a blue and a orange/white tapped

any help would be great.

Ok, NM, i had the right wire, but Panoz had apparently spliced into another wire next to that one near the ECU and when I pulled the tach wire to splice into it the other wire came loose and was grouding out. What would they have tapped into that wire for? it said "User 2" (I had the old harness mixed up)

New tach works, just need to fix the water temp gauge now! it appears i have a bad sender.

New tach works, just need to fix the water temp gauge now! it appears i have a bad sender.

G8rBob and I have installed analog gauges in our WC, start a thread on the water temp gauge for more info. G;-)

Thanks, i got it. The sender wire had a little stray strand that was grounding out on the head. pulled the wire and shrink wrapped it and everything works great.

Here is the new set of analog gauges.

http://www.extremespeedonline.com/gallery2/main.php?g2_view=core.DownloadItem&g2_itemId=94268&g2_serialNumber=2