Just got my 68 Barracuda out after about 6 months of inactivity. None of the above work. They did before I put it away. Car starts and runs fine. Brake lights and running lights work. So does oil pressure and charging gauge. Any guesses or is it all a coincidence and I have lots of different problems? Electrical gurus please any ideas??

It may well be multiple causes.

Fuses would be a good place to start. It could be corrosion on the contacts or a bad fuse. The firewall connector could have issues.

Perhaps you have had rodent activity? Are all the wires intact?

Bad grounds (corrosion again) could be the problem.

When a vehicle sits for a time, sometimes the float in the fuel tank fails and develops a leak (fills with fuel and sinks).

The voltage-limiter on the instrument cluster may be marginal or have failed. Might be time to replace the limiter with a solid-state replacement?

One thing at a time, you can usually concentrate on problem solving each issue.

start with the HL switch connector and the under the column dangling connector and the firewall bulkhead and tank sender "L" plug in connector and temp gauge sender on block and connectors under drivers kick panel: seperate all of em then plug em back together (corrosion can build up). pull the fuses & reinstall em (same thing). that'll get us started

the only thing those all have in common are the plug for the dash circuit board.

you might check that first, see if it got unplugged, or left disconnected last time you worked on it.

Rule #1 - Always check your grounds first.
When things that are seemingly unrelated fail at the same time, ground is always the prime suspect. Keep it simple at attach one issue at a time. Look for your dash grounds. I'm not sure but someone will know whether a 68 has a ground strap on the steering column or grounds through the dash mounts.
It's also important to know all the components that are or are not working (radio, wipers, heater fan, cigarette lighter, etc.). Of the items you mentioned, three are switched power (key on only) and one is unswitched (key on and/or off). Also, Mopar bulkhead connectors are notorious for having issues. A good cleaning never hurts.

http://www.mymopar.com/downloads/1968/68BarracudaA.jpg
http://www.mymopar.com/downloads/1968/68BarracudaB.jpg

Keep us posted. You'll find plenty of help on Moparts.

I am gonna start with the headlight switch as I replaced it last year when the dash lights died with one from my parts stash. I guess it is possible that was not a good switch so I am putting in a new one. I figure the gauges probably are from the dash regulator so I will tackle that later. Thanks for all the ideas!!

before replacing it you might pull the connector off of it & jump fire to the respective female cavities in the connector & see if every light bulb downstream lights up like they are supposed to (& no other circuits get bled over into/crossed over/powered up). that'll save you from replacing a good part/keep the frustration level from increasing/let you continue successfully diagnosing for the problem