Because Driving in the Dark Without Headlights Is No Fun on Sunday April 09 2006 in article > Tech Articles
Owners of C-bodies either have had, do have or will have problems with their headlight switch. This is a challenge for those with switches which are no longer available, '67 - '70 toggle/rocker switches in particular. Here is what I have found to be the culprit and how to avoid going down the "NOS Road" to repair it in such cases.
Ever had your C-body's headlights intermittently go out or flicker on-and-off for no apparent reason? The tail and parking lights still work as they should, so you check all of the grounds and connections in the headlight circuit and you replace your dimmer switch, but to no avail -- your headlights still flicker and/or go out. What could be causing this problem?
It is most likely the headlight switch itself since most switches also incorporate a circuit breaker system. The breaker's "points" have a tendancy to build up resistance over the years and overheat, distorting their bi-metal "arms" and eventually causing failure even though there may not be any system overload to which the breaker is responding.
"Now that I know that, I'll simply replace the headlight switch", you say. Not so simple, though, if you own a C-body for which the headlight switch has gone obsolete from all sources. This applies especially to those cars built from '67 - '70 which use a toggle- or rocker-type switch: all such switches are discontinued and have been for years. I suspect that many of us will encounter the same situation with some push-pull-type switches in the not-too-distant future. Your choices are to try to locate an NOS (New Old Stock) switch which can be time-consuming and costly, obtain a used one which may soon fail also, or do what I do: fix the old one yourself!
This repair should only be attempted by those who are already somewhat familiar with Mopar electrical systems and are comfortable disassembling electrical components which were never designed for disassembly. After you have disconnected the plug and removed the switch from behind the instrumant panel (an adventure in itself), you can usually disassemble the switch by CAREFULLY prying the piened-over pot metal "indents" away from the bakelite insulator on the back of the switch. If you chip the insulator, don't panic: it can usually be epoxied. As you separate the insulator from the body, pay careful attention to where all of the springs, detent balls and contacts go because NO ILLUSTRATION of this exists anywhere (that I am aware of). Now locate the breaker's "points", straighten the bi-meal arms if necessary, clean the contact faces and solder them together with silver solder. When you reassemble the switch, put it back together with a little dielectric grease on all of the moving parts and contact surfaces. If the pot-metal pein-over areas were snapped off during disassembly, drill through the metal case and into the insulator with a #89 drill bit and tap the holes for tiny #4-40 brass screws. Obviously, DO NOT let these scews come into contact with any of the contacts inside the insulator.
"Now wait a minute!" you say. "What if the system DOES get overloaded someday? Won't my car turn into flambe' a la Mopar?" It most surely will if you don't follow the next step. You MUST now mount an in-line breaker which matches your car's circuit load capacity (ususally 20 amps, but CHECK YOUR SERVICE MANUAL). I recommend using a modern push-in fuse holder in conjunction with a push-in circuit breaker (available from any decent auto parts store). You may have to modify the fuse holder slightly to fit the breaker into it, but be sure that the breaker's blades are completely insulated from the grouded metal of the dash. Now locate the battery (hot) wire in the plug (it is black on my '70 but, again, check your service manual). Remove it from its socket by depressing the small tab which retains it inside the plastic plug (don't cut the wire instead!). You can buy female terminals such as this one (P/N 784491) and corresponding male terminals (P/N 784490) at NAPA and crimp or solder one of each onto either end of the fuse holder' wire. Push the fuse holder's female terminal into the headlight plug. Then use a male insulator on the male terminal (P/N 784530) and a also slide afemale insulator (P/N 784531) onto the original female hot terminal, and connect them. Reassemble your system; you are now done and you haven't cut a single wire in your harness.
If you must buy several of the terminals and insulators just to get the few pieces you need, do not be upset. You have Mopars; you will use them sooner rather than later for other repair/update projects. And, of course, you can share them with your Mopar buddies, too!
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