Ok so the other day I was driving my 98 blazer to work and the battery light came on and voltage dropped to 9...drove it like this for a few days and then all my gauges dropped and it finally quit on me a mile from work. Replaced the battery less than a month ago, so I changed out the alternator and had my husband jump me...everything seemed fine battery light went off and voltage was at 14.2...so here is the issue I have now....I can start it up, drive it...everything is fine...once I kill the engine and start it back up the battery light comes back on and the voltage drops back to 9....as long as i leave it sit for a few hours when i start it up everything is fine...once i kill it after driving it is when I have the problem...I had them test it at autozone and it came back as "No voltage" I have no idea what this means....can anybody help?

 

You had autozone test what? batter or alt that came back no voltage?
Sounds like a bad connection to me at the battery, I think second gens are side post batteries as well. Look at the battery connections real well and clean them VERY well.
Look at the threads on the bolts that thread into the battery, they are known for stripping because its not enough thread that goes into the battery, and usually made out of brass.

 

They ran a test on battery and alternator...I also replaced the connectors on the wires to the battery...

 

Since you replaced the battery and alt, have you had an issue with it dieing from low voltage?

I would check the voltage at the battery while the truck is running with a digital multimeter.


If you dont know how, put the positive lead from the multi meter on the positive of the battery, and then put the ground/negative of the multi meter somewhere on the truck body, any bare metal, dont put the ground/negative of the multi meter on the battery ground.

See what voltage its actually putting out.
These gauges are notorious for being off.