The Studeblogger

Wednesday, September 16, 2009

Wiring Harness Replacement, Day 1.

Well, I hadn't really planned on this job, but some things just demand to get done all on their own.

After putting the new distributor in Barney and getting him going, I was futzing around inside and was, once again, taken by the rat's nest of messed-up wiring under the dashboard. I knew that the wiring harness was going to need replacement soon after buying him; there was a bundle of wires hanging out from beneath the ignition switch that had bare ends with tape over them! And there were other things, like the fact that the heater blower circuit was open... the headlight beam selector was bypassed... the horn circuit had shorted out and melted the harness for about a foot... and the fuse block was literally broken in half.

And the thought hit me: why wait? Why not do it now, before the car's back on the road? Because once I'm driving it, I'm not going to want to take it down to do this job. Also, I don't want to be standing next to a smoldering heap of metal on the side of the road somewhere because I didn't do it!

Luckily, I'd ordered a new OEM-style harness from Studebakers West in Redwood City. Mr. Biggs on the SDC Forum had told me early on that SW were the ones to go to, since they make their own harnesses from factory loom charts. And let me say, it's a beautiful piece of work!

So, after talking it over with my wife, I plunged in last Sunday. I'd sought advice on the Forum about how best to do the job; some told me I should drop the steering column and remove the entire dashboard. But a couple of guys told me I could do it by removing just the steering wheel and the gauge cluster, and working through the gauge pod opening. Since I already had all of the gauge pods removed, I decided on this course of action.

One of the guys on the Forum told me that no matter how long I thought the job would take - it would take about double that! All I can say is, was he ever right :)

So, Saturday night I laid out my new harness on the living room floor. I'd already gone through it with a continuity tester and identified the wires, tagging them with P-Touch labels. (Yes, that's anal-retentive. I believe in being prepared.)

Just to make sure, I went through with the wiring diagram again and was glad I had - I found a couple of mis-labeled wires (one, meant for the overdrive solenoid, was labelled "To coil positive"! That would not have worked.)

By the way, if you need a wiring diagram for your car, you'll find the ones in the Shop Manual fairly useless. Go to Chuck Collins' archive instead and find the one for your car. Trust me, you need this!

You'll find a thick rubber grommet where the harness passes through the firewall. This is installed by slipping it over the engine-compartment wires and fitting into the firewall hole. The wires must be fed through the firewall from the passenger compartment; the grommet is then installed from the engine side. This means you cannot pre-install the grommet before the wires go in -- something I had to learn the hard way.

I've been collecting parts for a while, so doing the harness also means replacing the nasty old painted gauge surround with the nice chromed one I've had waiting. Seems that, along with other austerity measures, Standard gauge pods were painted silver instead of chromed! My new one won't be "correct", but it will look much nicer. I also unearthed the new headlight switch, instrument light dimmer, heater control cables and other bits and pieces I'd assembled to replace what was broken, worn or just plain old.

Before diving in, I went around the car with the digital camera and took still photos of every wiring connection, plus video of everything with narration - just in case I mess up somewhere (cross your fingers!).

Finally it was time to get into the dash, starting with removal of the crappy Grant GT steering wheel. Why is it every two-bit hot-rodder wannabe has to put one of these things on? Getting the wheel and mounting hub off instantly revealed one reason the horn never worked: about a foot of thin wire wrapped around the turn signal's cancel switch, accompanied by two crimp-on butt connectors. Hopefully, the real horn wire is still in the column and can be retrieved, but I won't know until I pull the Grant adapter and switch collar.

With the wheel out of the way, I could get into the gauge pod and access the six screws that hold the bezel to the dashboard. There are four across the top and two on the bottom. Working through the mounting holes for the instruments, they were easy to get to using a mini-ratchet and 1/4" socket. Once these are out, the bezel is loose - almost. I found two trim screws on the bottom of the dash pad, adjacent to the steering column, that must come out. Then, the bezel is free to pull forward. I put some painter's tape on top of the steering column to avoid morking the paint up. I also unscrewed the ignition switch and four rocker switches and let them remain with the harness so I could photograph their connections.

Woo hoo! I could finally get to the interior of the dash. And boy, what a mess! Wires that went nowhere. Pulled-apart butt crimps with bare ends. More melted wires and electrical tape. Unprotected power taps coming off the main battery feed. Made me really glad I decided to do this project now rather than waiting!

Studebakers have no fuse panel per se; inline fuses are scattered throughout the harness along with two circuit breakers (one for the headlights, one for the windshield wipers). You'll find the breakers at either side of the pod, clipped to the backside of the dashboard frame in little holders. Headlight breaker is 20 amps, wiper is 5 amps. Mine were both 15 amps (go figure).

At this point, I took time to document the connections to the fuse panel. Okay, flasher panel would be more accurate, since there are only two fuses on the board and the directional flasher can is mounted here too. Naturally, there were also some accessory power leads screwed on, none of which powered anything. One lead, a big white one with a black tracer, was so obscure that I took my knife and cut open the remaining plastic tape so I could find out exactly where it went!

I'd started working in the car at 11AM; it was now 6PM and I'd finally reached the place where I was ready to cut the old harness at the firewall. The plan, put forth by Mr. Biggs, was to cut the harness and leave the engine side attached, so I could thread the new harness through the hole and just swap the connectors, using the old ones as a guide.

So I went and got my wire nippers and began snicking through the bundle on the engine side of the firewall, one wire at a time. And AGAIN I became very glad I'd decided not to put this job off! It seems that the pesky horn wire meltdown, in addition to burning through the harness wrap, had also managed to scorch the thick main power lead that goes from the alternator to the ammeter.

So, after 7 hours, I finally got to pull the old harness free of the dash. It was a long, tiring day, but I'm really glad I did it, and I have a good feeling that with all the research and pre-planning I've done, the new harness will go in pretty easily. It'll have to wait for this coming weekend, but that gives me time to get a few odds and ends - fuses, bulbs, breakers and sundry other goodies.
In addition, I've sent my clock off to get rebuilt by a pro, so when it comes back next week it'll be ready to go in that hole in the middle of the dash where the blanking plate was!

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