I am trying to install an aftermarket 12 volt aux. heater in my 71 series 2a. It is a direct connect to the battery with the reccommendation that a 30 amp inline fuse be installed in the positive lead. I decided to go one step furthe (actually 2 steps) and install a 30 amp circuit breaker right to the bulkhead, add a switch in the dash (because I have the heater in the way back) When I installed everything last night, as soon as I connected the battery, the breaker kept resetting and the pos. lead got very warm. I'm sure I followed my mechanic's instructions, BUT...it was 10 degrees, dark and was getting a little frustrated. Should the circuit breaker be connected in-line with only the positve lead? Or should one post be pos. & the other neg.?

Thanks