by Sue and Ed George and Wayne Perkins

It's a typical Mopar problem with the 1960s and 1970s're driving down the street and the headlights start flashing on and off all of a sudden. If you touch the headlight switch while this is going on, you'll find that it's hot.

The likely cause of this strange Mopar phenomenon is corrosion between the female and male connectors in the bulkhead connector on the firewall. This corrosion causes too much of a current draw on the headlight switch, causing the circuit breaker in the switch to open, which in turn, shuts off the headlights. In a few seconds time, the circuit breaker cools enough that it closes, which turns the lights back on. It's embarrassing that all oncoming traffic thinks you are flashing your lights at them, besides being annoying and dangerous.

While the bulkhead connectors can be cleaned with a solution of water and baking soda, this is only a temporary fix. To cure the problem, you will have to replace the male and female connectors inside of the headlight wiring harness plug and bulkhead. First, there are a few things to consider. When you unplug the wiring harness from the bulkhead connector, you will see that not all of the slots in the plug have connectors in them, depending on the optional equipment your car is equipped with. REMOVE AND REPLACE ONLY ONE CONNECTOR AT A TIME! THE CONNECTOR MUST BE REPLACED IN THE SAME SLOT THAT IT WAS REMOVED FROM!

For this installation, we are recommending you use NAPA/Belden part #725147 female connector and part #725145 male connector. These parts are superior to the original equipment because they have better copper plating which allows for better contact.

When looking at the bulkhead connector on the firewall, the top wiring harness plug will include the windshield wipers, neutral start, back-up lights, etc. The center plug contains your charging system and ignition system. The bottom plug is the light wiring harness. Unplug all wiring harness plugs from the bulkhead connector on the firewall. You cannot replace them in the wrong position, as the plugs are all made differently to fit their particular part of the bulkhead.

Begin the procedure by removing and replacing the male ends in the wiring harness plug. It is just as easy to replace all of these ends as it is to spend the time to trace down just the headlight wire ends. Squeeze the sides of each male end with small needlenose pliers while pushing the connector and wire out the back of the plug. (See Figure 1) Cut off the old male end as close to the end as possible and strip the wire insulation back 1/4".

Insert this wire into the new male connector part #725145 and crimp the tabs. Optional and recommended: place a small amount of solder on this crimp connection. Slide the new male connector into the same slot it was removed from. As mentioned above, only remove and replace one male connector at a time. Continue this procedure until you have removed and replaced all of the male connectors in the headlight wiring harness plug.

Next, you will want to release the bulkhead connector from the firewall so as to work on it under the dash of the car's interior. To release the bulkhead connector, squeeze the spring clips on either side of it while gently pushing it through the firewall. (See Figure 2)

Now, go inside the car to replace the female connectors on the bulkhead connection. You will need a very small pocket screwdriver to depress the tang so as to remove the female connectors. You can't see the tang, so push the small screwdriver end into the bottom part of the connector and pull the wire out the back. (See Figure 3)

Cut off the old connector and strip the insulation back 1/4". Put the wire into the new female connector part #725147 and crimp the tabs. Optional and recommended: place a small amount of solder on the crimp connection. Slide the new female connector back into its slot. Only remove one female connector at a time and always make sure it is replaced in the same slot it was removed from.