Ok this all stated with pulling the dash, that's done and new heater cor in. Trying to test the blower and have problems. I think I finally have the vac lines the right way and went to start the car to test and no power. No lights no horn and now now power at the fuse box. I am in trouble now did not want or need an electrical problem. When I was connecting the vac hoses heard what I thought was a click and thought that was strange, well it must have been a short as the ac her fuse blew but I have no power on the car battery is good so I need to trace from there and no power at fuse box with the volt meter....what's next open to suggestions for now I have to learn pwr schematics? Bb 78 The heater core was not leaking and now I have multiple issues....leave well enough alone!

My only thought is the fusable link. My friends 81 fusable link blew last year returning from a vette show in Rogers AR. And he had no power anywhere, that could have been the sound you heard. The fusable link is by the starter. I hope this helps you.

I'm with John....sounds like a fuse-link popped. There are a couple down by the starter, and prolly one(or more) in the harness that runs across the back of the engine on the firewall.

Here's a couple of pics of what they look like. The ones by the starter are usually about 6"-8" up from the starter in the harness, but you can usually see them.
The first pic is of the fuse-links on the driver side junction block, inside the fenderwell.
The second pic is of the ones that run across the firewall, right around the wiper motor.
I had some pics of the ones by the starter, but I can't find them, for some reason....
Test for battery voltage on BOTH sides of the fuse link. Most of the time, once they blow, the wiring is very soft, and you can tug on it, and pull the wires right out of the link...proving it has blown. Replacements are available at most decent parts houses.

I just torched the corvette! Kidding I am ready to! Ok before crawling under the car since I don't have a lift in my garage I decided to check the starter solenoid wiring harness by the distributor? When I put the neg from the meter into the black grd and the red from meter into one of the double red wires doming from the starter I get 12 volts? If I put it on the red positive from the battery to this harness no volts, so I do have good battery but positive is getting from the battery to one of the double red wires but not the main positive from bat to starter to the harness, If someone can translate this to me I would like that, iam going to look under the car now then the electrical diagram which I am not an electrician. But pos bat power is getting to 1 of the double red wires up to the harness connection so pos is coming from the bat to where that is hooked up to the starter but not coming out the main red bat cable from the starter?

Ok just got back from under car. Putting respecter to red cable bat and black meter to black ground get 12 volts,touching the other two red wires which are on the same screw the main red from battery get 12 also. That is all the wires attached to starter! I see another red wire but it is broken and cannot find the other end dangling anywhere, not sure if this is problem but need to check wiring diagram how many red wires are there, two other wires coming up to harness have fuse in them and don't look gooey. Question the top of the starter harness has 4 slots 2 side by side which I take black ground and red bat And 2 side by side red must be the in line fuse red wires. When I test them the black and one of the red wires in line fuse gives me 12 volts The black and red right beside it bat I mthinking no juice so this must be the problem or the one that is cut. But why am I only getting volts from 1 of the two red fused lines unless 1 in line fuse is shot? So getting 12 volts from 1 red in line red wire that's it. Also checking thought there were to be another wire on starter for ac blower power? Don't see it? Going to the wiring diagram?

Ok enclosing a pic drawing of what I have?

Imma thinking the problem is here....



The red/white wire goes to the the headlight switch. The other red wire pretty much powers the rest of the car. It also branches off and goes to the alternator. Check to see if the red wire on the alt. has 12v. The purple wire is the start signal from the ignition switch.
If you don't have a wiring diagram, I can e-mail one to ya.

I don,t have a purple just the a red one which seems like it comes up to the starter harness by the disturb cap.it plugs into the 4 outlet plug and it is the same level as the black ground with the two red wires below it that have the fuse. I did not have luck finding the fuses before foe the Alton or hood light so not sure I will find one. Can you put a normal fuse in and what voltage? Will wire it to the battery and see if volts at the altinator, still concerned about the purpl wire. My diagram shows purple going to the blower hookup and that is where I have the 2 purple wires with rubber cones around them but cannot find the origin of the pwr to the purple. I attached the lead from the blowe to the red coming from the relay and the blower worked,soon after that when I was connecting the vac tubes is when I heard what I thought was a short sound, that brings me to the current position. I have another bolt from the starter like some wire should be attached to it but ,cannot find a diagram that shows me I less that is for the purple? Ok thanks had enough for a day. Thanks for you help. Mark

The "purple" wire on my car does not look purple at all.  It looks more black with some reddish flecks or stripes in it.  I was confused by that, too, but by process of elimination I figured it had to be the signal wire from the ignition switch.  Car started so I guess I assumed correct!  Good luck!

The purple wire goes to the small terminal on the solenoid that is closest to the engine block. On the cars up to '75, the other small terminal on the solenoid would have the bypass wire going to the ignition coil. '75 & up cars do not have a wire on this terminal, so you will have one small terminal towards the outside of the car with no wire(s).
The large terminal on the solenoid should have the battery cable, and usually two, sometimes more "hot" wires that power the rest of the car...headlights, horn, etc. These smaller wires will have fuse links. If one of the links burns/blows, then whatever that wire powers on the car will be "dead".
You can cut out the fuse links, and splice the two wire ends together to get power back to the car. It is BEST to replace fuse links with new ones, since they help keep the car from burning to the ground in the event of a major short.