Yesterday my '96 Z28 "check engine" light came on and the amp guage
seems to be running a little on the low side, even with a new alt.

So, I am attempting to drive my wife to the hospital, I get 3 houses down
the block and the car stops dead, no electrical power at all. I make a
quick check of the battery cables, they seem tight. Course I was under
a little stress at the time.

My question then, Is there a fuse that might have let go and caused a
loss of all power ? What size and where might this fuse be located,
if it exists ?

Thanks

If the alternator is not charging the battery, it's going to go dead. Was it the check engine or check gauges light?

It was the check engine light. About 4 weeks ago I had the check engine
light, brake light, and ABS light all come on, the altenator was supposed
to be the guilty party. It was replaced.

I usually ride my motorcycle but I try and drive my Z every week. Yesterday
morning the check engine light was on, but car ran fine, never even turned
over slow, battery seemed to be charged.
Then yesterday BAM ! Turns over and runs fine, check engine light on,
car stops running, complete loss of electrical power.

This car got hot 2 years ago, and blew a head gasket. It sat for 1 1/2 years
while I made car payments and figured out what to do. I went with an engine
from Jasper and replacing just about every other part. New battery, battery
cables, sensors, opti spark, etc. Now about a month ago an altenator.

Yikes.
Now she no run. No power. Like a switch got flipped. Or a fuse blew.

I found the problem. There is a small positive wire that runs from the positive
battery cable to a junction block very near the battery. The wire was
corroded and broken. Maybe a past battery installation put the battery
on the wire ? Who knows. I replaced the wire and it fired right up.
Good deal. I appreciate your reply too, thanks.