Kind of new to the site and was wondering if i could get some help here, i have an 04 ram 1500 hemi slt, i am rebuliding it and recently tried starting it and wont turn over. i had to replace ingnition which i had the truck running after that was replaced, and also the cluster. Now when i try to start it all the gauges light up, fuel pump kicks in untill i turn the key and NOTHING! all gauges drop. thought it was my battery untill i noticed the small red light flashing on the cluster so im guessing something to do with safety and the computer??? Any ideas

 

The security will let it start and then die.

Check for a bad connection at the starter. I've seen the toothed washer on the battery connection at the starter get full of corrosion and caused a massive voltage drop at the starter.

 

Make sure fuse #23 is good as well as all others. Check and double check all connections and grounds. Make sure the starter is wired correctly. I have wires the solenoid backwards before and had the same issue as you are.

 

That sounds like the security light that flashing, when I arm my factory installed system, that light flashes