I have not been driving the old '70 in a month...had to replace the battery, it wouldn't take a charge. Then, with new battery it would not start, (nothing, no starter engage...) so I knocked on the solenoid 'cause I don't know any better and still no luck. The next day the truck turned right over and started.
Now the dome light wont come on, the light switch will not activate it but I noticed it on at some point while working on it. A few weeks ago my horn would not work but it worked yesterday while driving.
I'm wondering if the solenoid could cause such weirdness, since the positive connection goes thru it. I checked the fuses with a multiM for continuity and showed ok.

Any ideas appreciated,
Chris

 

Bad connections at the battery or bad ground someplace?

 

Ever check voltage ? instead of continuity? because a voltage drop would tell you what a resistance check won't, and its best to know that you have full source voltage and compare that to the other loads in the circuit because any significant drop would tell you straight up and I agree with mkoser to fact that you could have a faulty ground or a loose connection somewhere,judging by the sounds of it.