Are the drum magnets polarity sensitive? My controller shows 2 dots in disconnect position. When trailer harness is connected I receive an SH on controller, if I step on brakes nothing changes. . If I turn lights on I get a normal reading on controller and a response if I step on brake pedal. I have a second trailer and when connected to it everything appears to be normal. All lights, on problem trailer are grounded through a common ground, which is also grounded with negative from battery to trailer frame, along with common brake negative. . All wheel brake magnets have been disconnected and reconnected to facilitate suspension upgrade.
comment by: John - 4/6/2013
Magnets are not polarity sensitive. Just get one wire to a good ground and one wire to a good connection for the controller output. Does not matter which.
SH indicates a short on the brake output circuit somewhere. One magnet with a bad connection will cause it. Per the owners manual the probably causes are as follows:
1 - Brake wire sees short during idle condition
2 - Use of some test lights or non-Tekonsha testers can cause this problem Patrick B - 4/19/2013