I replaced the battery in my 94 coup this morning, turned the key and she roared to life! Drove for 15 minutes or so, then parked. 15 minutes or so later I went to start her up and got nothing. The lights come on but no sounds at all. Almost like the ignition switch had no power to it. I shifted into neutral to see if the neutral safety switch was the problem but still nothing. After 15 minutes I finally pulled the other car around and jump started the vette.

I am at a loss at what can be wrong, any help would be greatly appreciated.

 

Did you check the voltage of battery? Since you just changed it, but were able to jump it try the easiest thing first, make sure the cable terminals are making clean contact with battery terminals.

 

I’d agree with Corvetterules. Check the free stuff. The issues you’re having match the symptoms that I’ve had in a couple of different cars.
My suggestions start with checking both ends of the battery cables and cleaning them WELL. Also, any grounds needs to be checked. These ground connections may need to have their surfaces sanded and new connectors installed. We’re driving some older cars now, and these connections tend to get fouled with dirt or rust. I’ve been known to re-drill chassis grounds to make sure the new screw is going into fresh metal.

My next suggestion is one that took me an entire summer and into thanksgiving weekend to find.
When I had my ‘68, I had similar symptoms and It just about put me into the rubber wrench crew!
The fix was that I went to Radio Shack and got some “Color TV tuner cleaner.”
But that was about 1980. Now I’d say get some electronic component cleaner at your local parts store.
The fix is to get in and unplug your main harness bulkhead connector and spray it down pretty good. Do it to both halves of the connector. Plug it back in and see if it helped. I’ve never had to do this on a C4, but my ‘68 had a bolt holding the plug into the
female side, so there may be one. Just use a flashlight and look.
I hope this helps. Best of luck.
One last thought. I don’t know if your car is a stick or auto, but if it’s a 6-spd, this may be a place to look.
I currently have an ‘89.
The original owner I got it from had a lot of trouble with his clutch master cylinder leaking. After going thru a couple clutch masters, it eventually trashed his bulkhead connector. He had to direct-wire all the connections as back then, he was unable to get a connector without an entire harness.
Again, I hope all this helps.

 

One thing that a lot of people seem to forget is charging the new battery. A new battery has usually not seen a charger in a while and It is wise to charge them "completely" before putting it into use. If a battery sits the electrolyte can stratify and this causes a loss of battery power. The only way to fix this is to charge the battery completely and let it bubble a bit.

I also recommend that people clean every battery connection. Then use the battery terminal spray on top when the battery is installed and working properly. Now you can check your Alternator to be sure it has clean connections and is working properly.

I wish you the very best in resolving this issue!
Chris