INOP Susp Dump Switch - 87FC35

[Alan]

I think the system on my 87FC35 may be a little unique. Here it is:

1. It has an air leveling system. (It's great. I never use the HWH
Jacks).
2. The Susp Dump Switch on my DASH doesn't work.
3. The levers for my HWH Jacks are just outside the door in a
compartment. There is ALSO a susp dump switch inside this door. THIS
SWITCH WORKS.
4. I need to Dump the system before I use my air leveling system, and
it's always a hassle to go outside to dump it before I go back in and
push the air levelers on the dash.
5. I assume (perhaps incorrectly) that since there are two susp dump
switches, they work kind of like a 3-way light switch in your house
works. ...And therefore either my dash switch is out, or there is a
problem with the wire from my dash switch to where ever it goes.

Here's what I DON"T know:
1. When you flip the Susp Dump switch, what happens. Does it send 12
volts to some air switch? Does is complete a circuit for some air
switch (ground)?
2. Where are the air release valve(s) for the suspension.
3. Is there a controller for the air release valves. ie. Where does
the wire from my dash switch go?
4. Is there supposed to be 12 volts at my switch?

Even with wiring diagrams, I've pretty much given up on trying to
trace wires. Using tracers and the diagrams, I've never been able to
trace one.

I can do some basic electrical testing with a Fluke multimeter, if I
know what to look for.

Thanks for your help!
Alan
87FC35