RMBillings

I installed a set of headers and side pipes on my 1974 Corvette and now I have no power to anything when I turn the key. Battery is fully charged with no issues. When I turn key there nothing comes on. Could this be some fuseable link somewhere?

Any help would be appreciated. Thanks.

drywall guy

Bear in mind I’m no expert but it almost sounds like a bad ground …. Find it and check it

carriljc

"no power to anything" needs further elaboration.... not being nit-picky but for clarity.... I suspect you may have blown a fusible link near the starter (assuming it's wired like my 68). But lets answer a couple of questions:
1. do the headlights come on?
2. do the brake lights work?
3. Is there voltage at the alternator output post?
4. is there voltage at the starter connection post?

The answer to this will help us narrow it down.

Peterbuilt

Locate the battery negative cable (#1) and follow it to where it connects to the frame and clean and securely tighten the connection and the bolt.

RMBillings

There is no power to anything. When I turn the key forward I get nothing on the dash and no starter at all. When I pull the headlight switch there is nothing. I have looked over the grounds and all are good. I see power down to the start on the main lug and 1 of the smaller terminals. I have checked the fuse box and all fuses look good. Is there some wire that feeds the fuse box and does it go through a breaker??

RMBillings

There is power at the back of the Alternator.

RMBillings

I have run a test light on all the fuse panel connections and there is no power in the fuse box. Any ideas why?

carriljc

Oops....
I just re-read your answer. If there IS power at the back of the alternator then it will after that.

Do the Brake Lights work or NOT? Do your emergency flashers work? I ask because those things work REGARDLESS of key-switch position.

Does your ammeter deflect when you turn the key to ON?

Still looking.... meanwhile here is a 74 schematic from the web..... looks quite similar to my 68.

https://www.keystonestatecorvetteclu...tte%201974.pdf

RMBillings

Nothing work. No lights, guages or anything. It acts like the battery is disconnected bit it is not.

carriljc

Ok. Good to know.
Take a reading at the starter post. Just to narrow down the field..... in case the alternator output is getting power via a circuitous path. Once we know that then we can move along.

RMBillings

Here are readings from everywhere. Battery - 12.6, Alternator - 12.6, Electric Window Breaker - 12.6, starter main lug - 12.6, Starter smaller lug left - 0, Starter smaller lug right - 0 and coil - 0.

RockyL32

Do es the dome light come on when you open the door?

RMBillings

No it does not.

RMBillings

Should 1 of the smaller lugs on the start have full time power? I know one of the smaller ones is for power in to trigger the starter to spin.

Hammerhead Fred

You should be checking that the fusible links just above the starter are not blown.

RMBillings

I found the issue. There was a fusable link over by the Alternator in the wiring harness. Does not look factory but it had pulled out.

carriljc

Good job!
I was gonna suggest eyeballing the fusible link on that second lead off the B+ post on the starter..... even grabbed a snapshot.... but probably worthless if it is not stock.
BUT anyway -- fusible links should be "soldered" in so you probably wanna do that.....
here's is what I had just snipped: