i converted my 55 1st. to 12 volts months ago, but never wired the heater until now. i wired it up and it seems to work fine but the switch gets hot and that happens quickly. does this mean i need a voltage reducer and if so where should i install it. should i install it on the wire leading from the ignition switch to the heater switch. the heater is not original but it was hooked up to run on the 6v system (the heater says "ford" on it)