I have an 01 Blazer.the transmission went bad (no reverse) so I got another tranny from a junkyard.I took the old one out along w/the transfer case.put the new tranny and the old transfer case back in.I hooked the battery back up and to my surprise I got the famous clicking noise you get w/a dead battery or bad connection.I made sure the battery connections were good and then jumpstarted the blazer and it started up.now after starting it up I went to the gas station and on my way home the ignition system just shut noff w/no warning.no chugging,no funny sounds.it was as though someone turned the ignition ey off.if I go to turn the key now all the dummy lights come on,the radio comes on,heater etc..... BUT when I turn the key all the way to engage the starter the dash lights and everything goes out and I don't even get a click,complete silence.I changed the battery w/a known good battery to no avail.I removed the starter thinking maybe it wasn't grounding,cleaned it up really good and re-installed it,nothing.I removed the starter again and bench tested it and it fired right up w/out a problem.I am really thinking I have a bad ground somewhere but do not know where.I did not remove the factory ground strap on the back of the pass side of the motor and that strap looks good still.the neg battery cable looks really good.where is there a ground that I may be missing that would not only prevent the starter from engaging but would also shut off the ignition system?



oh by the way,all fuses are good in both fuse block locations and so are the relays.

 

Sounds like you may be experiencing an ignition switch failure...

 

found a cple threads on here pertaining to the ign switch install that will def help.thansks!

 

Here are a few more that might help:
Anatomy of the Ignition Switch
Ignition Switch Replacement - Book Method...
Ignition Switch Replacement

 

I FOUND MY PROBLEM!! when I started to attack this tranny removal I took a bolt out of what I though was a bell housing bolt,but it wasn't.this bolt was on the pass side N went into the head.this bolt held 2 ground straps to the head.I completely forgot about this bolt and the 2 ground wires associated w/it.these two wires being off were the cause of my blazer being dead.def a dumb thing I know,easy fix though.