themerryjo wrote:
1. When I apply 12 volts to the front 2 drums I can hear the magnets energizing but neither of the back ones sound like they are working, is it ok to just use brakes on one axle or is that going to feel too weak for 7000#?It will feel (and be) too weak for the trailer. Only drive it that way to the repair shop.
2. I am planning on running some 12/2 SO cord from trailer front junction box to a second junction box located between the wheels and from there branching off to each wheel with 14/2 SO cord. Is this sufficient?Yes, that is sufficient, a bit of overkill. As you discovered, SO cord is VERY good in the elements...
3. If I end up buying new brake assemblies, what are opinions on self adjust vs manual? Do they actually work reliably as intended or with a little age do they not self adjust anyway?I have no direct knowledge of self adjusters, but when my manual guys need replacing, I will replace them with auto-adjusters.
My comment on the SO cord is backed up with 30years as a commercial master electrician...but, at the very least, ADJUST Them! If it were me, I would inspect, repack the bearings and go from knowledge.
Tim