absolutely no power....

drove to work the other day and my 85 classic was running fine, altho wife said she thought she heard a funny noise through the radio. When came out after shift at work and opened the door, no interior lights, nothing at all turn the key...totally dead,

I double checked and nothing was left on to drain power...got a boost and it started fine and ran great all the way home although the headlights flickered a bit once or twice. Once home and turned it off and tried it again...back to absolutely nothing..total blackout.

I figured maybe the battery gave up the ghost, so picked up new one. When opened the door the interior lights came on but soon as turned the ignition key I heard a single click like a solenoid or something making contact, then it blacks out again. I went back under the hood and looked at the battery wires and jiggled them a bit...hard to tell if they are the culprit, since they seem ok...back in the cab the interior light is back and the whole scenario repeats...not sure if its the ignition switch causing this, but if it was then how come the car will start perfectly with a boost...its like the battery is isolated from the rest of the electrical system somehow. Any ideas would be appreciated.

it was loose ground wire to chassis...must have missed it in the darkness...usually have a flashlight in the car for just such instances, but of course my kids spotted it and god only knows where it is now...lol.

good to see you found the problem