Could an AC Power Surge Cause Trailer Breakaway Switch to Melt

Question:

We were in Mexico for the week and when we attempted to hitch-up to leave, we found our breakaway switch pin was out and melted. The evening before, when inside our trailer, we heard a crackling noise, but didnt know what it was. Now we think it may have been the switch frying.inch There are sometimes power surges in Mexico. Do you think a power surge could effect this 12 volt item? We do have a power converter on the trailer. The trailer was not plugged into the truck power yet, but was plugged into Mexican shore power. We had to clip the wire to disengage the brakes. Everything else weve checked so far seems to be fine. Our brakes are working and our battery is charging. We did order the replacement switch from you just now HM20010. Any other advice/info would be appreciated.

asked by: Sue R

Expert Reply:

The DC wiring system and the AC wiring system in a trailer does have protective features between the two; mostly handled by the transfer switch and fuse/breaker panels. But I suppose that it is possible that a power surge could have worked its way through somehow.

But I think a more likely scenario is that some how the pin got pulled out some causing the contacts inside to touch which completes the circuit from the breakaway battery to the trailer brakes. The battery will keep apply its full power until its drained or something shorts out.

Replacing the switch with another such as # HM20010 is a good start but I would have all of the brake wiring, the brakes themselves, the hubs, bearings, and spindles all inspected. If the brakes were on long enough it could have generated a lot of heat somewhere and damaged something else. So it is better to err on the side of caution.

expert reply by: Michael H