Deuce light switch overheat?

[doghead]

I would not try to supply any converter off a light circuit.

I would draw directly from the batteries, and use a relay to switch it on(powered from the light circuit should be ok).

Or simply powered it on when the ignition is switched on(with a relay), since you need brake lights even when you headlights are not on.

 

[Dodge man]

When you install the new unit, measure it's current consumption and then install a fuse inline with it that has a slightly higher rating in order to protect the main light switch and the rest of the electrical system.

 

[cmpman]

I like doghead's idea. Signal the converter from the ignition thru a relay. Protect the main power to the relay (and hence to the converter) with a circuit breaker of reasonable amperage. I would not use a fuse since the blowing of the fuse would result in the loss of trailer lighting.

 

[cranetruck]

If you have access to the December 2005 issue of Military Vehicles Magazine, "The highway deuce" article covers light and other potential problems when on the road.