I'll add to this one a little bit. There are higher amp rated electronic reducers available for the wiper and heater motors. Mid-Fifty has them for $63. These electronic jobbies are awesome. Mine hasn't been getting hot, like Julie mentioned, but I only have one installed, and only on the gas gauge. I will be adding the bigger electronic one for my original 6 volt wipers, though. I'm going to replace my heater with a 12 volt motor, only becasue the switch is dead, and if I'm gonna change the switch, I'm gonna change the motor. A lot of places talk bad about the porcelain volta-a-drops, but I'm with Julie. They have been around for several decades, and I've never seen a rig have a problem with using them.