Hello , Iam new here and im looking for help I have a 99 blazer ls 4.3 starts fine then will stall everthing goes dead no power to any electrical system. the first time this happened parked car and tryed starting a few hours later. stared right up everthing worked fine. drove to get gas this morning tried to start and no power at all again waited several hours still won't start. any ideals were to start Thanks

 

Start at your battery connections.

 

Battery connection ok, Strangest thing Started every morning for a week Then went out Saturday no power at all, let sit for an hour and dome lights and security light comes on. waited another hour car starts. I replaced the 175 Mega Fuse car starts , but afraid to take on the road, any other ideals.

 

Every electrical component, (except the starter, it is not fused) gets its power through the 175 mega fuse. If the fuse is faulty, nothing will get voltage, which is what you're describing. If the circuit from the battery positive terminal to the mega fuse has a poor or non-existent connection, you'll experience the same problem. There are 2 red wires on the fused side of the mega fuse: One goes to the secondary air pump under the radiator. The other one goes to the underhood fuse panel. If that wire has a poor or non-existent connection, you'll experience the same problem also. Start by taking each connection apart, shine them up, and put them back together, tightly.

 

My 2001 Blazer was running great this after noon. Tonight when I tried to pull it into the garage the dash lights flash for an instant and then everything went DEAD.

Where is the Mega fuse that you changed? I search and cannot find anything.

 

Under the battery tray.

 

after removing the battery, I saw some plastic cases and opened them; one had a blown 30A fuse. I have no idea what the fuse is for, but everything is working great again.

I hope this helps someone.

 

The 30 amp fuse is for the secondary air pump under the radiator. The 175 amp Maxi fuse should be close by. That's the one that can make everything go dead. Maybe you bumped it while replacing the 30 amp fuse. Or possibly there was a poor connection at the battery that was repaired when you reinstalled it.