Help passing a wire through the firewall.
 

I'm hooking up a Air/Fuel gauge to an oxygen sensor and want to make it a permanent install. I've looked for preexisting holes in the firewall, but to no avail.

Has anyone else done a similar project and can give me some ideas about how to get from the engine compartment to the passenger compartment, without removing the rear deck?

Or am I dreaming and the rear deck will have to come out.

Thanks,

I wonder if you could go through the center tunnel? That might be a good route.

Noel,
I may be way off base here... Your 1980 car (assuming it is a US model) already has the O2 sensor as well as the Lambda computer - so you already may be 3/4 of the way finished. In my car, since I am just one year younger than you, was to hook the A/F meter up the the wire on harness going to the number 2 green wire - this 'hooking up' I am referring to is simply removing the harness from the brain, taking off the harness cover, and neatly threading my A/F meter sensor wire to the number 2 wire, and then reattaching everything. It has worked perfectly for the past seven months without having to do any special routing through the firewall. The 'free' green wire in the photo is the one to the A/F meter itself and it was simply inserted into the same hole as occupied by the green 2 wire (from the O2 sensor). I hope that this helps.

http://forums.pelicanparts.com/uploa...1098019037.jpg

Noel--
On my '85, there is a hole on the left (driver's) side from the passenger compartment through the firewall where the rear window defogger wires go into the engine compartment. Remove the rear deck and look at the bottom of the window; from the engine compartment you should also be able to see the wires going into the car near the left hinge.

I taped the wires to a clothes hangar and fished it through. If memory serves, I went from the engine compartment as the angle was better.

Removing the rear deck isn't hard - its held in by a couple of screws and a metal tongue in the middle. Remove the screws, push the deck of vertically to release the tongue then slide the deck out (you'll need to disconnect the speaker wires also).

If your car doesn't have the optional rear fog lamp, why not use the existing spare wire in the harness that is in with the left tail lamp wires? It already goes to the dash area ...

Thanks guys. I appreciate the advice. I may try to hook into the wire that goes to the "Brain," as it is only a few feet from the eventual loacation of the unit. Otherwise I will look into the other ideas. It's good to know I have so many options.

Thanks again!!!

Noel,
I just installed LM1 and was doing the same thing, looking for existing hole to pass a wire through.
I looked at the center tunnel area and it was to congested to pass a wire with connector head on it.
Where I found access hole is by driver side rear passanger foot well. Imagine seating down on a jumper seat the hole is located behind your left foot heel area. Remove floor carpet mat and pull verticle section of the carpet and you will see a rubber gromet with about an inch big diameter. I just punched a hole through the soft center part and connected my wires.
My car is 86' 930. I am not sure if there are differences in different year and model when it comes to holes in the chasis, but check it out.

Young

If you do need more wires, drill a hole into the center tunnel bulkhead below the fire wall. Clean and prime, paint and insert a grommet for the wire to run thru. Then dress the wire into the pass. compartment where you want it.

THanks again guys. I ended up running the wire through the tunnel in where the tranny shift rod comes through. 30 minutes and 6 zip-ties later it is done.