I am going to install a fuel pressure gauge in my 02 saleen.Just looking for the easiest route to run the wires into the car from the sending unit.I really don't want to drill another hole through the firewall unless i have to.Anyone done this?
It should be the same on your car, but an 03 Cobra I helped install a fuel psi gauge we found an easy way to route the wiring through.
There is a large grommet in the firewall pretty much in front of and slightly above where the brake pedal is located. It's probably a 3-4 inch grommet. We taped the wires neatly to a small pointed rod (a clothes hanger could work in a pinch) and then heated the tip of the rod with a torch. Carefully, the heated tip was passed through the grommet, which the rod sort of "melted" its way right through. Stay towards the edge to avoid any of the existing cables in the grommet. The wiring was passed from the engine compartment towards the interior. Let the piece cool for a moment, and slowly pull the rod through letting the wires come in. It was pretty easy, and the grommet was never removed so there was no hassle putting it back on.
Wish I had a pic for you, but only the finished install pics are on my site in my sig.