Well I have been able to put 100 miles on my car and some of the wrinkels are working them selves out. I repainted the drivers side fender so the car is all one color and in general things seemed to be coming along nicely. New plugs new cap and rotor new battery and alternator.
Then Wam! I cant get any power over 40mph to 50 mph my dash lights dont work and all of my idiot lights are on like I lost the alternaror belt but I didn't. and my fuel sending units termanals are croaded beyond repair (green dust is all that is left of the top one). Not where I had hoped to be at this time of the year.
so my questions are is my battery bad or is it more likely my alternator? it seems like I have a ground short some place but I cant find any loose wires how ever if I rev the engine a bit the idiot lights all go off. the volt meter is also low right around or just under 12. I just don't know where to start. ... Ideas anyone?

 

the volt meter is also low right around or just under 12.

Voltmeter should read over 12, close to 14 volts.
To check the alternator, connect a voltmeter across the battery and raise engine rpm over 2000. The volts should go from 12 to 14.
Should get the same result if you put the voltmeter pos lead on the main terminal of the alternator and neg lead on neg post of battery.
Probably not a bad battery. Maybe a corroded connection between battery, body (earth), and or alternator?

Good luck

 

Try running a second ground to the engine using some big *** power cable (one of the ac condensor studs makes a good spot if ya don't have ac). This is a good idea for anyone and should hopefully raise your volts. Make sure all your connections are clean. Sounds like you might have some electrical gremlins to sort out.

 

Do as Bruceman says.
My guess is that it is the alternator.