Project '64 Continental: Wire Harness Rebuild


In the last update, we covered the discovery and destruction of a very old and very hacked up wiring harness. In this edition of "how Ben spends his free time" we'll look at how to resurrect that rats nest. I'm not a master electrician, as such I don't have many spools of delightfully colorful wire with which to properly copy the wire color code. Since Radio Shack is apparently now an iPod accessories retailer, I went to Murray's for their wide selection of well priced wire. We're not dealing with a ton of variation here, so red, white, black and gray were picked up in 16 gage sizing along with a selection of necessary connectors. All the other bits and pieces were already awaiting my return to the garage.

Project '64 Continental: Wire Harness Rebuild

Step one in the process is to size up and cut the proper length of replacement wire. Here you have a bit of freedom to make changes. Make a wire longer if you want to route it differently or need additional slack, shorter if it's slopping all over the engine bay and you want to clean things up. Once you've stripped a quarter inch of insulation off, mate the clean end of one wire to the clean end of the other, I like to mesh the two together in line. At this point, grab your nice hot soldering iron (you are a lazy bastard if you use the twist and tape method) and begin heating the joint. If you are adding your heat shrink already, make sure it's at least six inches away from the joint - heat conduction through the wire may shrink the tubing in a place you don't want it to (guess how I know that). When the wire is hot enough, the solder will flow into the joint, advance the solder as it melts until you are happy with the amount solder in the joint (it should look all silvery). I'm thorough, so I flip the joint over and work the same way from the back. Let the joint cool for a moment and test it by pulling from both ends. If it fails, you suck, try again. When the joint has cooled to the touch, slide the heat shrink over the joint and you can use the hot soldering iron to shrink the covering in place. Of course if you're doing a lot of tubing, it's a easier to just use your heat gun.

Project '64 Continental: Wire Harness Rebuild

Now for connectors. Just crimping them on is not a great way to do things, they inevitably fall off or the wire corrodes and the electrical connection fails. That doesn't mean the store bought connectors can't be used. Make sure you've got your heat shrink precut and slipped onto the wire, then go ahead and crimp you connector of choice onto the wire, but when you're done there, cut that nasty hard plastic cover off. Now you've got a nice place to solder the mechanical connection together and provide some insurance. Heat the connector and capillary action will pull the solder pool into the joint, cool. Perform the magical heat shrink tubing trick again. With all the wires repaired, I decided to go with a temporary wire management solution. I bemoaned using spiral wrap last time, but since I wasn't able to figure out what the brown mystery wire leads to, spiral wrap was used in the interest of easily taking things apart later.

Project '64 Continental: Wire Harness Rebuild

While I was in there I decided to rework the hard line into the carb. The lazy bums that put the Holley on got a hard line designed for fuel delivery from the back of the engine. Great except the fuel comes from the front on this car. As a result the hose ran in a big loop from the fuel pump over the passenger side valve cover, around to the firewall and then forward to the hard line. To fix this, I took the line, packed it with sand, capped both ends and bent it by hand to fit in a forward facing orientation. Happily as a result of this change I was able to remove about two feet of excess fuel line (throttle lag? naaah). For no apparent reason, the ignition vacuum advance was 6 inches longer than it needed to be, so that got clipped too. A much cleaned up engine bay now greets me every time I walk into the garage.

Project '64 Continental: Wire Harness Rebuild

Before hooking everything up, go over all the poles with a brass wire brush to make sure there is a good contact, then commence reassembly. Get a friend to watch over things as you turn on the ignition. Smoke = bad. Your friend should let you know if that occurs. If no smoke happens, go ahead and crank it over. If it starts you win, if it doesn't you forgot something (fired right up btw). And that concludes todays lesson.