need some help with my elctro magnetic brakes.

[bigcrunch]

On my 7 ton utility trailer ( non boat trailer there seem to be lots of knowledgeable members here so please help):

It has 2 axles 8 lug 7000lb ea w\ drums, I replaced all four brake backing assemblies new everything, same original drums\hubs. One tire on each axle I can get to lock up turning the brake controller 3.5 and up this is empty and truck pulling it on grass surface. Wiring on the trailer runs down the left side each axle has its own tee for power. Front axle left tire locks up right keeps rotating rear axle right tire locks and left keeps rotating. I re crimped all the connectors, checked the magnets with drums off and power to them all picked up the same piece of scrap metal, adjusted the shoes, all drums are round no scoring no outer lip. I jacked up the trailer all tires off the ground applied the brakes 3.5 I can almost turn the above mentioend tires the other 2 are locked, turn up the voltage I cant turn them by hand. They all spin freely with no brake applied. I also tested the voltage at the trailer side plug matches to controller. Last test I did was disconnect the plug wired a 12 volt battery right to the plug and pulled with truck same thing. Before I start guessing any suggestions????

 

[cmount1]

Verify the resistance for each magnet(coil), make sure there all the same. If they measure the same the next step is to test the voltage drop to each wheel. I would start at the trailer plug, place the positive lead from the volt meter on the B+ wire, truck side of the harness, and the negative lead on the B+ trailer side of the harness. Record the voltage reading with the brake applied, I would like to see .75v or less. This verifies the trailer connection, I don't think this is your problem but It's worth a look. Now you need to check the drop at each wheel with the brake applied between the B+ at the trailer connector and the B+ where it enters the backing plate and then check across each magnet. Between the supply at the nose of the trailer and the wheel there should be anything large, 1v or less. I'm not sure what you might see when you check across the magnets but, they should all be the same. When you find a voltage that stands out different from the rest then you find the problem.

 

[bigcrunch]

Ants. Lots of them in the wiring harness T for the brakes with eggs. I cut the shrink wrap looks to be factory they just started pouring out. I am going to let them discipate then check it again.