Electric brake voltage low at 7 pin.

[philodog]

I have a 2021 1500 with the factory brake controller. With the gain set to max on Heavy Trailer mode I am getting minimal braking, not even close to locking up the wheels of a 1000lb trailer. Measuring the voltage at the electric brake wire on the 7 pin with the trailer disconnected, I am only getting 10-11 volts when the settings are at max (cluster gauge showing 100% braking). Is this normal? I thought it should show full battery voltage at max. On a separate note when I check voltage at the trailer brakes they are only getting 6 volts. The wire coming from the plug gets 10 volts when I disconnect the wires to the brakes but only 6 when I reconnect either one or both brakes. Thoughts?