Hello,

I have a 1999 Blazer LS (4.3l Automatic) that will not crank. Wife was driving it home after a short trip to pick up food to go, almost home and it cut off. I was not home, and it took me an hour to get to her. The whole time she was trying to start it, but there was no crank. The interior lights and dash lights all come on like normal - but turning the key to start did nothing. No clicks, noises or anything to indicate it was trying to start. 1 time after I arrived it did crank for a brief 1/2 second - but nothing else.

Fast forward to today (approx 1 month later..) - I have replaced the ignition switch and starter. Neither of those were the issue, unfortunately. I took the battery and had it tested - it is good. I have power at the starter, I have tested with a DMM and have got it to crank by applying power directly to the starter. I have jumped the starter relay in the engine compartment fuse box and got it to crank. I have jumped the fuel pump relay and starter relay together and the truck starts with no issue and will run as long as the fuel pump relay is jumped. With the key turned to run, the fuel pump is not running. Only by jumping the fuel pump relay could we get it to run. Testing the voltage at the fuse boxes is good, and nothing sticks out as an issue yet.

From my early research I thought the park/neutral switch could be the issue, however a friend of mine is certain that the fuel pump would still kick on when the key was in run even if the park/neutral switch was bad. Can anyone confirm this? Moving thru the gears trying to start nothing happens as well. The back up lights do turn on when the transmission is placed into reverse.

Unless we are missing something, we are assuming at this point there is a bad ground somewhere. Does anyone have any advice on common problematic grounds that could cause the issues I'm having? Since everything else seems to be working fine - would this mean that the bad ground would be near the ignition system, or not necessarily?

Thanks in advance!

Jeremy

 

It sounds to me like it could be your neutral safety switch. Make sure you have no damaged wires going to it. I had the same issue years ago and it turned out that my intake gaskets had gone bad an were leaking down the back of the engine on to the nss and shorting it out. Also, check your ignition fuse for continuity. I also had a no start with a bad fuse. it wasn't blown but it was not conducting electricity for some reason.