Help with 12 volt question

[traveler]

I have a newly developed problem. First, I have an almost new battery and problems persist even when I connect jumper cables to the battery. So, bad battery not an issue.

I first noticed that the 12v light above the battery compartment was intermittent. Then it failed altogether and new bulb did not fix.

A day or two later all of the lights in the basement and the water hose compartment became inoperable.

There was full voltage to the lights and the associated switches worked ok.

I examined the 12v fuse panel. No red lights were on. Then I established that circuits 2 (motors), 8 (furnace), 8 (awning) , and 11 (hydraulics) did not light up when I pulled the fuse. All other circuits would show a red light with the fuse out.

Voltages on the hot side of the circuits--all of them--was about 13.5 with the fuses in place. This measurement was made on the terminals to the left of the fuses.

Voltages at those terminals dropped to zero with the fuses out on all but circuits 2,6,8,and 11, where it dropped to 11.5 (again without any fuse in place).

I am not sure what motor circuit 2 runs, but apparently the water pump motor is one of them. The water pump works but acts as if it is on low voltage. This jives with the low voltage measurement on circuit 2.

The hydraulics work, but I cannot tell if the hydraulic motor has low voltage.

I realize that this is a confusing set of symptoms, but maybe some of you have an idea about what I can check to further diagnose or fis the problem.

Thanks