I replaced the old dead converter which had three 12 volt fused circuits but only supplied 12amps. The New WFCO 8735 provides five 12 volt circuits, produces 35 amps and has a much better charger.

Disconnect the 120v wiring from the old converter

Cut the 12v wires off near the converter.

Identify the two 120v circuits. One is 14 gauge wiring for all of the 15 amp duplex outlets and the other is heavier 12 guage wiring for the 20 amp air conditioning outlet. I traced the wires to the outlets to be sure.

Wire the main 120v cable into the new converter. I used a new clamping strain relief. Note the two 120v outlet wires in the blue plastic strain relief. These will attach to the combo 20amp/15amp 120v circuit breaker.

The green ground wire and the white neutral wire from the 30' trailer cable attached to separate terminal blocks and the black wire is stripped and ready to attach to 30amp circuit breaker. I also connected the bare copper trailer frame ground (See in photo 2) to the ground strip. Other white wires and green or bare copper wires will attach to the appropriate terminal blocks as well.

The old converter did not have an input breaker as it depended on the one on the campsite power pedestal so I purchased one at the hardware store. This is safer, especially if I ever used a 50Amp cheater plug at the pedestal.

The black wire from the 30' 120 volt trailer cable is attached to the 30 amp input breaker. The 120v 20amp outlet wire is connected to the 20amp breaker position. The 15amp breaker position starts as a single black wire (6" long) and then attaches to two wires with the yellow wire nut. The wires are: one feeding the 15amp trailer outlets and one feeding the builtin converter.

Breakers in place. There is a clamp on the input breaker to keep it securely in place.

I recrimped the 12 volt circuit wires to the new converter. I used a terminal block to join all the white ground wires for the 12v systems including the wire that goes to the trailer frame.

I tidied up the wires with split loom. I installed fuses one at a time, determined what 12 volt items started working, and then label the fuse position accordingly. I confirmed the new converter was charging the battery (voltage at battery jumps from 12.6 volts to 14+ when plugged into 120v garage outlet.