The Studeblogger

Tuesday, September 22, 2009

Wiring Harness Replacement, Days 2 & 3.

Well, it took me a week to get back to it, but last weekend I got the time to finish installing the new wiring in Barney.

Since I'd already ripped out the half of the harness that formerly occupied the dashboard, I began installing the new harness by threading it through the firewall to the engine compartment from inside the car. The engine side of the harness is much smaller on the engine side than the dash-side bundle, which is why it makes sense to do it like this.

It was actually a little bit of work to get it through there by myself. I had uncoiled the new harness and stretched it out as far as I could, and the different circuit branches kept getting hung up on things (the seatback, the turn signal stalk, the steering column Z-bar) as I pulled it through. Finally, though, I got it all the way through and began changing connections, starting with the alternator wires (farthest point of the harness) and being careful to bend the bundle the same as the old ones to fit into the wire clips around the radiator support. Notice in the pics below that there are several clips at strategic locations to guide the wire bundle around the radiator, under the horn mounting positions, and elsewhere in the engine compartment.



Notice also that there are a few leads in the harness that are not connected. There are usually a few of these in any car; in my case, the low-tone horn and the overdrive relay. Loose wire leads are a big peeve of mine. They can get in moving parts, or arc to ground unexpectedly, so I always tie-wrap them to the main bundle, as you can see above.

I had left the engine half of the old harness in place and simply substituted the new connectors for the old at each connection along the way. Sure, you could use the wiring diagram, but why not make it easy?

Also, here's a plug for some good stuff. Caig Labs in Poway, California (right up the road from me) makes a product called DeoxIT. This stuff is magic! If you spray it on old electrical connectors, it will remove oxidation within minutes; the junk just wipes right off, without harming the connectors themselves. There's also DeoxIT Gold, which is a lubricant/connection enhancer that you spray on afterward. Lest you call BS on this, let me tell you that I've measured connection resistance myself in connectors with and without DeoxiIT Gold, and it does indeed seriously lower the resistance. You can get it at almost any Radio Shack, or Frys, or like stores. I used this on every connection under the hood, and on the dash switches as well.

Also, just to make sure that the underhood connections stay moisture-free, I used a dab of dielectric grease on every connection point. This is the stuff the factory uses in all the booted connectors to keep connectors from corroding or absorbing water.

After finishing the engine compartment, Iwent into the cabin. First thing I figured I'd do was to bolt the new fuse/flasher block to the dash, since it really locates the rest of the harness bundle. In my Lark, the flasher panel shares a mounting position with the driver's side air vent control - the vent rod bracket bolts to the bottom of the dash frame, and the same screws hold the flasher bracket to the top of the frame. I had previously installed all the connections and fuses that live in it, so I began to screw it on -- and ran into my first bit of trouble. The flasher can was too big; it interfered with the vent rod. I had read the number off the old flasher and gotten a direct replacement from my NAPA, but a check of the manual revealed that it was, in fact, the wrong flasher. How did the old one fit in there without banging on the vent control? Well, my old flasher block was busted - one fuse connection was actually broken off and was being held in place by the fuse! I think that a PO probably put in a flasher they had on hand, and when it didn't fit, he just bent the bracket forward, breaking the board! Luckily, SASCO had NOS parts in stock, and I got one before they closed down.

NEVER TRUST THE P.O.! After a hasty trip to NAPA, I installed the correct flasher and proceeded. In the pic above, you can see the difference between what was on the car, and the correct (short) can.

After that, things went pretty well. I routed the new wire bundle over the steering column support and into the clip that holds it down, and separated the pigtails for the various switches and instruments into their approximate locations.

Let me point out that while most fuses in a Studebaker dashboard are inline in their respective circuits, there are two circuit breakers as well; one 20A breaker for the headlights and a 5A for the wipers. They are located at opposite ends of the instrument nacelle. The headlamp breaker is in a holder at the lower forward left corner of the panel (think: just above the hood release, but inside the dash structure) and the wiper breaker is in a like holder on the right side, attached to the steering column Z-bar. While they are situated in such a way that you wouldn't know where to look for them if you didn't know where to look for them (figure that out!), once you know where they are, you can get to them pretty easily from below.



While the instruments were out, I took the opportunity to remove my defogger vent heads and attach new flexible ducting obtained from Studebaker International. It was nearly impossible to get the new ducts mounted properly while the vents were in the dash, but they're held on with just two small screws each. I snugged the new hose on the inlets and secured them with Zip ties, then bolted them back up to the dash.

Next step was to start hooking up the gauges and switches. I set the new guage bezel on top of the steering column and started hooking up switch wires according to the wiring chart. This is a bit tricky; first, the shift lever interferes with the bezel's direct entry to the dash; even in the "Reverse" position, you have the heater/defogger control cables attached to their levers, which must be guided through the dash structure. While these are flexible, the OEM cables are spiral-wound metal, not plastic-sheathed, and can be bent if you're careless. In fact, I managed to bend the rightmost cable but was lucky enough to try the controls while the cables were still accessible through the gauge holes, and I straightened it so that it could slide without hanging up. Also, the metal bezel can scrape up the top of the steering column pretty good; I wound blue painter's tape around the column to protect it during this operation.

After the switch and the Fuel/Temp/Oil/Charge gauge connections were made, I pushed the bezel into the dash and started installing the six #10-24 3/8" self-tapping screws that hold it in. How do I know what size they are? Because I lost one, somehow, in the dash structure. One minute it was in the socket, the next it was nowhere to be found - nowhere! This prompted a trip to Ace hardware, since I had also found a screw missing in the bracket that holds the parking brake to the dash. Ace only had 1/2" screws, so I had to shorten one to 3/8" using my Dremel.

The hardest connection to make to the left-most gauge is the oil pressure line. The gauge is a direct-reading mechanical type, so the line is a hard copper tube that attaches to the engine with a flexible coupkling, then comes through the dash and ends in a miniature double-flare that screws into a fitting on the back of the gauge. Try as I might, working through the clock and speedo holes, that danged line did not want to screw into its fitting. At this point, I'd been at it for 6 hours and decided to call it a day.

On Sunday afternoon, after a good lunch, I decided to try it again. I got into a better position ("better" being a relative term) with the help of a pillow and Mini-Mag and succeeded in getting the oil line installed, working from below. Let me tell you, it was about as comfortable as flying coach on a Delta flight!


After that, it took about 5 minutes to set the speedo in place and hook up its drive cable and the leads for the directional and high-beam indicators. Time to hook up the battery!

I crossed my fingers and put the battery cables on. Nothing sparked or leaked smoke, so I said a quick "thank you" prayer and put the key in the ignition, at which my first mistake became apparent -- the windshield wipers came on with the key; I'd installed the leads to the switch backward.

But that was no big deal. Now for the high-wattage stuff: the headlights, taillights, beam selector switch, turn signals, instrument lights. Success! All worked nicely.

I turned the key to "start" and the engine fired up after a couple of cranks - Success! But the key was turned right off as I saw, through the open hood, smoke coming from the new coil resistor I'd installed. (Studebakers West can't get the resistance wire the factory used to supply power to the coil when the key is in the "run" position, so they give you an old-style external resistor that mounts to the coil bracket.) I quickly went and pulled the cables off the battery, then checked the resistor. But the wires were cool; the smoke was coming from the resistor coil itself. I guess brand new ones just smoke a little when the current first hits them. I put the cables back on the battery and fired the engine again - sweet!

There were only a couple of small errors to fix, such as the connections to the wiper switch and the ammeter, which I apparently wired in reverse - the needle went to the "Charge" side of center when I turned the headlights on, and swung to "Discharge" when I revved the engine! But those were easy fixes, and I corrected them after work yesterday.

The one thing left to figure out is the behavior of the headlight/parking light switch. The parking lamp position of the switch doesn't seem to work - no lights on the corners in the center position, but they come on with the headlights like they're supposed to. It's possible that the switch is work out and not working right - we'll see.

The only part of the harness left to install is the back half that feeds the tail and reverse lights, but there's no hurry for this, as all those wires are in relatively good shape.  At least I don't have to worry about nightmares like the scene at left anymore!

Next project is getting the new master cylinder and brake lines installed, and she's on the road!

Click here for the final part of the wiring installation series >>

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