Gauges not working on 03

[markelectric]

Battery went dead on the 2003 (my fault) and rather than jumping it and stress the alternator, I hooked up a battery charger and let it slow charge.
When the charger said it was happy, I tried to start it. turned the key on and saw the gauges dive to way below their low settings then rise up to the low point. After the glow light went out, I started the truck, normal sounding start. when it was running, the gauges never came up to any value above the bottom end. I know the tank is near full, The voltage should be good as fast as the starter was spinning and so on.

The Tach does work.

I also noticed the ABS light on, the brake light on and the info center said "unknown driver" with a #3 key in it.
The radio was lit up but no sound from the speakers.
I seem to remember this situation on here once upon a time, but I cannot find a post similar to this problem.

Any ideas? Where to look?

Thanks in advance for any help

Mark