Lighting question

[markeb01]

For the rear lights, first check to make sure the fuse is good, and the connection at the fuse panel isn't corroded.

The most probable cause of your lighting failure is bad ground(s), especially on the parking lights. Stock, these trucks rely greatly on connections through the body to the frame to provide ground which isn't very efficient. As it gets older and components rust, there just isn't enough ground to close the electrical loop. If the bulbs are glowing they are getting power, just not enough through the circuit to bring them to full brightness.

The best solution I've found is to drill a hole somewhere convenient in the light bucket, attach a wire with a ring terminal and run to a common connector block near the battery. This post has a wire running to the battery, the frame, the body and the lights - and you'll never have bad ground problems again (dim lights almost always indicate bad ground). Ground wires have to carry as much electricity as the power side so they need to be the same size as the feed wires. Ron Francis Wiring actually has a kit for this.

Of course this assumes the sockets are free of corrosion and the bulbs also. A battery brush usually works pretty well for cleaning the sockets. Also, a small amount of dialectric grease on the bulbs and sockets will keep them like new for years. You can also solve some mystery problems by pulling apart every factory connector you can find and apply dielectric grease before reassembly.

The next probability with one of the these trucks is a bad dimmer switch, as they are often corroded from moisture. There is also a connector on the floor under the sheet metal plate between the rear of the drivers door and the seat. These conceals a connector where the front and rear harnesses connect. That could be loose or corroded. The headlight light switch is another possibility, but less likely than the dimmer.

Just from the age of the truck it's wise insurance to replace the entire harness. This stuff is 48 years old. All it takes is one short from a remaining piece of old wire to burn the rig to the ground. My personal brand preference is Ron Francis, although Painless is more highly advertised, and many of the restoration places make stock replacement harnesses if you're wanting to keep it original.

The tail light bulbs are number 1157. Just do a Google search for 1157 led bulb or 1157 led replacement. There are a bunch of outfits that make direct replacement bulbs you can put in yourself. Shop for price and quality as they are all over the map. Also, if you replace all 4 turn signal bulbs with led's, you'll have to replace the flasher with an electronic model. The led's don't pull enough amperage to cause a conventional flasher to operate.

Hope this helps, M.