K20 fuel system

[K204ME]

Hello everyone,
I'm new on the block, thought I'd stop by. I'm not the best mechanic in the world, but I'll bet I can be of some service here sooner or later....But for now, I was hoping for a little help myself.

Vehicle Info:
1983 K20 (camper special 'heavy 3/4' 1 ton frame and suspension as explained to me?)
4WD
350 motor (stock, no enhancements)

OK, here's the problem.... the motor just quit the other day, as if I was out of gas, just filled it up, so that couldn't be. I checked the carb and no fuel was evedent,
So... thought it was the pump and replaced it...no fuel.... thought it was the solenoid/ duel tank valve switch...replaced it too...still no fuel.
I checked the power from the fuse box (checked the fuses first) to the dash board switch, and from there to the valve. Everything shows good connectivity with 12 volts flowing.....I checked the 5 port connector plug at the valve for ware, but all looks good.

(Also, the dash full gauge went crazy the day b4 it went T.U. The dial went all the way around to about the five o'clock position (when full, it stops at 2 o'clock), then it went to the empty position and stays there...both tanks are full)

I finally ran a by-pass line around the solenoid to see if the line was plugged up, but I have fuel flowing and the engine runs fine, so the line isn't plugged up.

Anyone here have an Idea of what I might do next? Don't worry about giving bad advice....obviously I've been on a roll with that...so far

Thx for any help
Ron