I drove to work today and the car ran fine but the second I turned the car off everything was dead. No clock, no lights, nothing. The battery is just over 12V so it is fine. I was trying to troubleshoot the wires at the starter and how do I tell if the fusible links are burned up? If they are burned up would it prevent all power from going to the rest of the car? I have searched the forums and didnt see any answers to this question so any help would be appreciated.

Dan

 

Have you checked all of your grounds? If everything went off, I'd say it's a ground wire somewhere.

 

Check the neg battery cable where it bolts to the frame just under the battery box.

I'm pretty sure on your 75 you have 1 fusible link at the starter , and yes if it burned it will kill all power.
( in later years there were 2 links at the starter - 1 for the headlights and 1 for everything else)

 

Not sure about the differences between a 75 and 69….

But I had this issue. Seems the guy before me had the soderless connection in a wire between the starter and the horn. I had a test light. Went to the starter and there was juice. Went to the horn relay and nothing. Traced it back from there.

I would get a test light and go from the battery and start testing at the starter. Then the horn relay and work from there. Somewhere on this excellent site someone gave us wiring schematics. That is what I used.

 

I checked all the grounds that I could see... I tried to test at the Starter and didnt find any power there but I need to get a wiring diagram. Is the positive wire going straight from the battery to the starter? or is that the negative that is connected directly to the battery. Sorry for a dumb question.
Dan

 

Schematics:
http://www.nrjvette.com/johdotukset/?c=d;o=d

 

Thanks!

 

If everything is dead, start with cleaning the battery terminals. Even if they look clean they might not be making a connection.

 

 

If there is no power at the centerpost of the starter where the positive cable from the battery goes, you should have your answer. That means the starter is not getting power and that is fed by the cable from the battery. That is the black cable is the schematic.

So, either your post connection on the battery are bad
Your cables coming from the battery are bad
your negative is not grounded
or your battery is dead

 

There is another quirk 0f the 1975. This happened to me and a couple of others that I know of. There is a master power wire that runs along the firewall behind the engine that can fray and ground out because of its position in the harness. A good Corvette specialist will know how to troubleshoot this. Just one more possibility.

 

i had a simmilar problem on my 77. a few guys have had this issue and i've suggested it and it worked. if you look on the firewall to the passenger side of the distributor there are 4 or 5 plastic connectors right together, they look almost like big HEI connectors. these are the wires that carry the power from the starter to the fuse block. if one of those connectors is not making good contact it can kill the whole car. check them out, make sure they are right. like i said, worked for me and few other guys.

 

Thank you for everyone's suggestions and help. I traced the power issue to the block on the engine side of the firewall. The power comes from the starter and splits at this block, one going inside the car and the other going to the Alternator. The male connector inside of the plastic housing was broken, so if you move this wire around I Could get a connection. I just got a new connector and will splice it on tonight but we are all set. I appreciate all the help.

Dan