1983 Tercel SR5 - How to pass wires through firewall

Help! I've got a 1983 Tercel SR5, and I'm trying to run a pair of wires through the firewall, to operate a secondary horn (have problem with the main horn operation). I have looked around the firewall, and can't find a good place to drill. Plus, it appears to have double- wall firewall, so I'd have to match up holes etc.. There is some room to drill on the passenger side, but I'm afraid of hitting the heater core with the drill.

I'm trying to avoid completely tearing apart the dash and kickboard area from inside, if I can avoid it. I am hoping some of you can suggest good ways to pass a couple of wires (standard-size; like in wiring harnesses) from the passenger compartment through to the outside, even if it's through the floorboard (I have been advised against drilling there, due to moisture, fumes etc. getting into the car).

Suggestions welcome!!

Thank you all,

Lee Black Forest, CO

Reply to
Lee
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already through the fire wall. Drilling through the floor board is not the best plan, because of what you already mentioned. If following an existing harness is not possible you will have to closely measure to where a hole can be safely drilled, and sealed. Perhaps near the steering column is a possibility for either plan I mentioned. Take your time doing this and you should be fine. Good luck.

Reply to
user

Take an icepick and poke a hole in one of the existing grommets through the firewall. Then push the wires through, and goop it with a little glob of silicone sealant.

That, or fix your horn - it's probably easier than starting over...

Go to the Toyota dealer parts counter and get a Horn Ring Brush contact kit (~$5). Go to the auto parts store and get some silicone grease lubricant. Go to the drugstore and get a bottle of Isopropyl Alcohol and some long stick 'Cotton Applicators' - single-ended Q-tip on a sturdy wood stick.

Remove the covers around the steering column (Phillips head screws on the bottom half at the top of those deep holes). Get the brush holder assembly off, then swab the horn ring (on the back side of the steering wheel) with a few alcohol soaked swabs till you get most of the dirt, grit and old grease off. (This is important because it will keep the new brush from wearing out quite as fast, and eliminate the scrunching noise as you turn the wheel - at least for a while...)

Goop up the horn ring with some fresh silicone grease on a clean swab. Replace the horn contact and connect the wire. Test the horn. (Eureka!) Put the column covers back on.

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Reply to
Bruce L. Bergman

Hello to all,

This is Lee, the original poster. I wanted to post an 'epilogue' of the Tercel wiring adventure. We did not have to drill a hole in the firewall, BUT we did have to take off the left front fender, which itself entailed removing the left headlight assembly (for access to one of the fender screws) and the battery and its tray. There is a cable-chase inside the left fender - it goes from the firewall (from the interior; there are a couple of rubber boots the wiring harness and hood-release cable feed through) to the front of the engine compartment, and comes out a hole on the fender side, at the front inside engine compartment. It was a hassle getting the screws off (most were 10mm head, but the front inside-the-wheel-well fender screw was something like 11 or 12 mm). The other hassle was trying to unhook the antenna ground strap (also inside the fender), but it worked. I had neglected to hook up one of the chassis-ground screws behind the headlight; and nothing would work until that was reconnected -- seems fine after that.

Thank you for your help in all this,

Lee

Reply to
Lee

DAMN! You went through all this?!

On my '83 Wagon, I punched a hole in the large brommet in the firewall, and passed the wiring through there. Took all of 10 minutes!

Reply to
Hachiroku

I'm not sure what 'large grommet in the firewall' you would mean. On the 1983 SR5 Tercel 4WD, there is no obvious grommet (or even a place to drill a hole) that is apparent, at least on my vehicle. I looked all over the firewall, to do just what you said (and that had worked fine on older cars, years ago). There were a couple of places where carburetor cables (i.e. choke and throttle) came through, but for one reason or another they were not practical to feed wiring through. All the wiring harness that would normally feed through a grommet, was running inside the left fender, and never entered the engine compartment until it came in from the fender area, just behind the left headlight.

The only firewall place that even had a plausible clearance to drill a new hole, was on the passenger side -- and I decided not to risk it, because it would be about where the heater core is positioned, behind the firewall -- didn't want to drill through that!.

Is your vehicle the SR5 with the 3AC engine, i.e. the 4WD? I'll feel pretty sheepish if I missed something that obvious!...

Thanks,

Lee Lee

Reply to
Lee

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