After blowing a few fuses I've discovered that turning on the fan blows the 15A heater fuse instantly. The fan never comes on, although it worked when I brought it home last Thursday. All gauges, excluding speedo, die with the fuse. Any ideas?
Make sure the fan motor will turn. Could be debris, old hard grease that are causing the motor to pull too many amps. May also be a short, either in the motor or in the wiring. That you can test with a continuity tester/multimeter.
Your low speed goes through a resistor that cuts down the volts, so that may not let it pull enough amps to blow the fuse. But you may also have a short in the "high" speed wire, or you may have a bad resistor.
Some ans pull more amps than others. IIRC, the Taurus fan in one of my old rigs pulled 110 amps. New to cruisers, but make sure you ae using a relay rated high enough for the draw of your fan. No idea how to find out how much it daws, someone smarter than I will have to tell you that. Once the fan is at speed, the amps should drop off, it's just that initial kick.