View Full Version : 12volt 30 amp circuit breaker question

02-04-2007, 08:59 AM
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.?


02-04-2007, 01:39 PM
Just a thought, do you have a ground wire on the heater ?

02-04-2007, 08:13 PM
IMHO the circuit breaker is an uneccessary complication if you have the inline fuse. I would suspect the ground as well.

02-07-2007, 05:19 PM
Thanks for the replies. Yes the heater is grounded. I simplified the entire installation routine though. The purpose of using the circuit breaker instead of an in-line fuse is not having to replace a fuse everytime it blows if it does. The circuit breaker will trip, and reset automatically in 30 seconds. If it keeps trpping, you know there is a problem and address it without having to pull over and replace multiple fuses. At any rate, it is installed, working well, and the dogs are happy with the little bit of warm air they get in the back!:thumb-up:

Thanks again!

02-07-2007, 08:20 PM
You shouldn't be blowing circuit breakers or fuses, if you are you have a problem or an inadequate fuse. A fuse should only blow indicating a short somewhere.

02-07-2007, 08:55 PM
sounds like something my truck needs...