I after reading alot on internet, looks like I have a 90 model mustang harness from an auto matic car. I do not have the 02 harness, but plan on putting in a 5speed. I read that hooking up the wrong 02 sensor harness could burn up a computer, some type jumper wire. So should I look for a 5 speed hego harness?
I do not have the factory instrument dash, I am using after market gauges, do I have to have the VSS? If so could I just get it and never hook cable to it?
If your speedo requires a cable, source one from an '86 and older Mustang. You'll also need the transmission-mounted portion...not sure if those can be bought at a dealer or it's a junkyard found part..
Cliff's notes is that you are trying to swap in an efi 5.0 and harness from a newer Stang, correct? I'd stick to one exact year for all your wiring, as there are several one year only differences that will not correspond with a different year.
It might be easier to get a Stang's engine AND headlight harness, and repin those OR your body harness to work with each other.
If you need an O2 harness, there's a guy on corral I've bought wiring from for my '89 Stang...he's good people, trustworthy. In fact, working with him again right now for some small parts for the '84/'89 swaparoo I'm doing to these Mustangs. But that's for a different thread and shouldn't be any concern to you. I'll PM his contact info if you want to send him a line with your needs. PM for it if you want. :)
I was going use a cyberdyne speedo http://www.cyberdynegauges.net/speedometer.php, or not one at all, since I have a extra "GPS" I will just put on the dash.
The t-bird did not have anything but the dash and headlight harness in it, the engine harness and computer was gone already. So I was just trying to use the engine harness and computer, and the injector harness.
I found the right 02 harness from a mustang salvage yard here today.