another 98 blazer with a dead battery 3days

I have the same problem with a 98 BLZ. replaced the starter Which was bad. "I am not sure about that either". Anyway the same thing goes on with the battery thing. The battery is brand new and the dash wiring was worked on at the dealership before we bought it. Turned off the override dash button, still no change. Alternater was tested also. Stumped! this is the LS Blazer Electric everything.

If you have the factory installed delco radio, try removing it for a few days and see if that fixes the problem.. I had the same problem on my LT and I found the memory on the radio was drawing TOO much power when ignition was off.. Common problem! Hope it helps ya!

I'll second that on the factory radio. The '95 Blazer I sold would go dead after three days and traced it down to the Delco radio.

Your "new" battery could quite possibly be bad, not an unlikely scenario. It may even be a refurbished battery that was sold as a new battery.
Also, since you mentioned the wiring had been tinkered with (dealer or not), this could be shorting the battery somewhere, causing discharge.

had one the light would stay on under the hood and run the batt.down did not find it till i was walking out side after dark

I had the same problem, turned out when I leave the keys in it as I always do there is a position where you think that it is off, it is not and it drains the battery, also I started unplugging anything in the cigarette lighters and got a new battery, has worked ever since, till my alternator went out on Sat now replaced that and everything is in order, so far (knock on wood)

I have the same problem with a 98 BLZ. replaced the starter Which was bad. "I am not sure about that either". Anyway the same thing goes on with the battery thing. The battery is brand new and the dash wiring was worked on at the dealership before we bought it. Turned off the override dash button, still no change. Alternater was tested also. Stumped! this is the LS Blazer Electric everything.

Some quick questions:

1.) Did you charge your new battery FULLY before you installed it into the truck.

2.) Did you check for some shorts or dead grounds?