Title:  Fuses in the Fuse Box

Weak Link:  standard fuse box

Models Affected: Trucks using the glass fuses, mainly 74-80 RC/TD & Trucks

What happens:  Over time, the fuse box clips develop corrosion and resistance from use, and can cause the clips to actually melt thru the box itself.  This is mainly prevalent on the blower motor fuse clips, as it is the most commonly used high current fuse. This is compounded by the fact that the switches used for the 3 speed fan fail regularly, and when they do, they can overheat the wiring.

Cheap Fix:If your fuse clips have melted thru, you can either find a replacement fuse box in a JY, or wire in a new flat fuse style.  Use a 30 amp holder, but put a 20 amp fuse in it.  If you are careful, you can cut away the melted part of your fusebox, and the new holder will just fit in from the bottom side. This will allow you to continue to use your fuse box cover. Splice it in using good crimp splices.

Strong Fix:  Replace the fuse box with an aftermarket unit.

Either Fix: When you do this, it would be a very good idea to check/replace the fan speed switch, thermal resistor panel in the heater box, and the wiring if it shows any signs of overheating.  The thermal resistor panel is located just under the glove box on the side of the heater box and works with the switch to give you a 3 speed fan.

Contact:  fuse holder: Any auto parts store, Painless Wiring, Francis WireWorks
switch & resistor panel: NAPA, Dodge

This should be done in conjunction with cleaning out the heater box, or vice versa.  The thermal resistor can cause a fire if debris in the heater box gets against it when it is hot.