Tom,

The blower fan draws its current right through that connector, and it can be pretty high (as much as 20 amps on an old blower fan). So any resistance can cause a lot of heat. Clean up any metal contacts as best you can so that the resistance is as low as possible. I would also, if you are able, measure the amperage draw on the blower fan at its various fan settings, particularly the high setting to see what it is pulling. If it is pulling more than 20 amps, I would encourage you to put a new one in. But even new ones, pull quite a bit. The best thing you can do, hands down, is to limit the time you allow the blower fan to run on high. Run it for a few minutes on high, but get into the habit of turning it down a notch after that, it significantly reduces the amperage draw if you do this (one notch lower will almost cut the amperage in half), and will help that connector last a lot longer.

 

 

any bad connectors will cause a high resistance, check the fan resistor terminals.

I have decided to add a Relay before the fan speed select switch, which will protect the Ignition Switch only, but leave all fan speeds available

I dont want the internal contacts of the Ignition switch cooking

harness/relay for headlights as well