OOOOOPS, What's in the tunnel?

[William Miller]

I may have F up big time.
I am welding in seat brackets for my 996 seats.
I was warned about the fuel lines that run down the inside of the tunnel on the drivers side.

So, I started on the passangers side.
No fuel lines, but it appears the wiring harness, or 2 are run in some sort of a conduit along the top edge of the inside of the tunnel.

I have welded some brackets on the bottom 3/4" of the tunnel, But only tacked 4 spots in the area where I think the wires run.
This was before I took a close look to see what might be there.

At the front of the tunnell It looks like 2 harnesses come out the front, go across in front of the pedals and up into the trunk (right under the gas tank filler.) I think/hope one of these is the battey cable.

I have decided to stop to investigate.
I'm planning on pulling the harnesses out to check to see if/or what I melted, and have to repair.

Anyone replaced the harness? Where does it go in the front and back? I'm guessing that it mostly goes to the lower half of the fuse blocks and I'm going to have to pull it thru to the back of the car. (It's pretty tight back there.) Might have to drop the engine.

Anybody done this yet?
How about the other side?
What do I have to look foreward to?
I do think my fuel lines are all steel.
I know the vacuum line runs thru there somewhere.

Is there anything delicate inside the rockers?
Thanks as always!

[VaSteve]

Bill,
Here is some info I got last fall...

What are these things in the tunnel?

[William Miller]

Thanks Steve.
I can see / feel the following:
Brake cables
Heater cables
Throttle linkage
Clutch linkage / cable
Vacuum tube comming out of the front where a rubber hose is attached.
Spedo wire
Fuel lines comming out the back of the fire wall and go above the torsion tube. (Haven't seen them in the tunnel.)
Two wire harnesses described earlier.
Shift rod and coupler

It's what I can't see or know about that I'm worried about.

[William Miller]

TTT Bump

[len911]

William, I just replaced the tunnel on my '74 last month... Including some pictures from the underside. Harness runs in passenger side, towards top. Clutch & acc run low on the driver's side. Hope it helps! Lou

[William Miller]

Thanks for the great pictures. I couldn't have wished for better shots.
First, It's not as bad as I feared. It looks like with some slack I could shift the harness foreward and back to look for dammage and hopefully repair.
Except, I can't finish the weld without some clearance. Wheels turning in head......
Pictures tell a thousand words, but I still have some questions. I laveled the pictures to make sure I understand that everything is what I think it is. Can you confirm?

Now some questions:
You mentioned clutch and acc on the left lower side. What's acc?
Did you have fuel lines in there? I think 74 should have CIS supply and return lines. Right?
What are the two other rods or tubes in the last picture?
Can you measure up from the floor to the bottom of the conduits.
It looks like the drivers side is higher which would be great because I'm not going that high.

Do you recall which end the wires come out? If I need to get them out should I unhook the front or the back? Does the back end up at the 14 pin connector near the rear fuse block?
Do you think that connector will fit thru the hole in the back of the tunnel and thru the conduit. I'm guessing the battery cable also goes thru that one so I'd take that out first.

If I can do it from the back there might be less stuff to disconnect?
What did you use to cut the spot welds? (a drill?) I want to remove the remnants of the seat brackets that I cut off.
Thanks for all your help your a lifesaver!

BTW why did you replace the tunnel?
Thanks!

[len911]

William, acc is the accelerator rod. Including picture.

It runs on plastic bushings. Yes, '74 has 2 fuel lines. The tubes you are referring to are them. I believe the PO hacked the tunnel to replace the fuel lines. I was lucky to find one here from a fellow Pelicanite. This is what it looked like...

I believe the 14 pin connector should go thru the tunnel. I would disconnect the harness at the rear and pull it forward. Battery cable connects to starter. Harness is one piece so it has to go thru the tunnel. Including some ref pix. I pulled my whole harness since PO had cut it all up to paint. I bought a Painless wiring 12 circuit kit to rewire. Car will be used for DE.

I did not cut up the spot welds, but I know there are tools to do it. (Eastwood auto) Brake vacuum tube was cut on replacement tunnel.

Height (from old tunnel, since new one is welded is 1.5" on pass side and 2" on drivers.

Took us about 4 hours to do the tunnel and cage plates. Came out really nice!

I hope this help! Good luck! Lou

[William Miller]

Wow that looks much better now.
I went home and pulled the harness and battery cables out.
I did it from the front because there was no way to feed them from the back with the engine and tranny in place.

Luckily, all is well with the wires. Not even any melting of the outer sheath. With the wires out of the way it was nice to be able to finish the welding without the worry!

Here are the passenger brackets finished. These are about 2" lower than the stock seat supports. They are strong as hell!

Since the fuel lines are much higher on the drivers side there will be no concern. Thes brackets are about 1" below the lines.

Thanks for the pictures. It made it much easier to figure this out!

[Rufblackbird]

wow Len, those are some great shots, especially the underneath of the tunnel and the finished product!

[Bobboloo]

Did you leave a cable or wire of some sort to use for pulling your harness back through when you're done?

[Bob Goding]

A rather graphic example of just how valuable this website is!
Where else could one get this kind of information?
Thanks again to Wayne and all the contributors.

[len911]

William, glad everything worked out! Take care... Lou

[William Miller]

Thanks again Lou! BTW, I removed the remnants of the brackets. I centerpunched each spot weld and drilled some of the center out. Then used a wood chisel to pry the metal up and away. each spot poped away and left a little speck to grind off with the dremmil. It was no big deal. Probably 10 min for each.

Bobby, I was going to pull a wire thru at first until I realized it won't be that hard to fish one in later. Pulling the harness back thru twards the front probably won't be as easy. I'm going to get my son to help feed into the back while I pull from the front. I did lube things up with liquid soap which helps a lot!

[Joeaksa]

Excellent shots of the tunnel areas. Cannot believe what the PO did but you sure did a good job of correcting the damage.

JoeA

[Inniswhe]

William Miller ,

I am resurrecting this old thread because I am searching for the clearance from the bottom of the gas line conduit to the floor so I can weld in new seat rails and want to clear the gas lines like you were doing back in 2005. I see that you identified that same measurement and asked Lou for it. The thread never indicated what the dimension was.
Do you recall how much clearance there is ?


Thanks

[William Miller]

Inniswhe:
Bringing back some memories with this thread.
I totaled the cab that October.
Fortunately the insurance settlement was good and I'm driving an 81 Targa which recieved all the good parts and recently a 3.6 transplant.

The seat brackets outlived the car and are up in my attic with the seats.
(Will sell some time...)

I never did take measurments, but if you look closely, the answer is in the pictures and should be easily seen in your car. The conduits are a box section with a flange (Turned down) running down the length. The flanges were spot welded inside the tunnel. The spot welds are visible on the outside of the tunnel. Assuming the spot welds are at the approximate center of the flange then the actual conduit is just a little above the spot welds.
So it seems you should be good if you stay below the spot welds and you will be fine.

Looking at the picture, the gas line conduit is higher than the one for the wiring.

If you pull off the parking brake mechanism, you can feel exactly where they are and even see them with a mirror and a flashlight.

I really liked the final results with those 996 seats and these brackets.
Hope your project works out for you!



Had I known that, I would never have pulled the wiring harness out.

[Inniswhe]

Thanks for the insight, I now recall seeing the spot welds you mentioned. I think I will confirm via the parking brake access and proceed cautiously.