I bought a 1997 Blazer from a private party seems like a nice truck. The guy I bought it from is a mechanic and had just replaced the engine with a used one from a junk yard with about 100,000 miles on it. Engine runs perfect good oil presure all that but the next day after I bought it I went to start it and battery was dead so I went and bought a new one fully charged it and did the battery swap. Started right up and I drove it for about an hour everything was fine. The next morning SAME THING (dead)! Battery cables are clean, volt meter shows 14.5 volts or so when its running. It starts fine within a couple hours after shutting it off but anything longer than that its completely dead. I made sure all the lights and accessories are off when i take keys out. I love the truck but I am kinda nervous about being able to find out what and where the draw is comming from. I don't have the money to drop it off at a dealer so I definately have to do this myself. Any ideas would be awesome!

 

See if this dead battery thread helps out. Also, see if the 'search' function brings up anything useful.

 

Ok last night I left the battery charger on it, went and put the keys in turned the key everything lit up on dash like it should and it would not turn over. The volt meter was above 12.6v and the battery charger is working fine. I turned the key a few times after like 8 turns of the key it started like eit should, starter sounds good and alot of power turning it. Shut it off and did the same thing...... started after like 5-10 turns of the key. I hear a click noise in the glove box is that the ignition control module? Is that a possible culprit of my parasitic drain? Like i said in the first post truck runs, drives ,starts fine but when it sits for more than a few hours the battery is dead. It was not until this morning it would not start with a full battery.

 

Sounds like a failing or failed ignition switch.