So my monte decided to not start on me. Sometimes get a single click and sometimes not even that from the starter. I thought it might have been the starter so I ordered a warranty one, as i just replaced it with a TYC starter but after the swap it didn't work. I checked the older starter once it was out and it tested fine. The voltage going to the new started via the purple trigger wire is only 1 volt and then drops to 0.6 volts. It should be 12v

Next I thought it might be the ignition switch not working well as I had that issues before causing weak/no connection and thus voltage to the starter trigger. A quick test at the ignition relay showed the following pattern which I think is normal

TOP Of engine fuse block (From left to right and top to bottom)
Ground ----- Hot at all times
Open Infinity resistance ---- 12v when ignition turned to start

So it appears my ignition is fine, starter is fine. I also tried starting in neutral, and moving from neutral to park several times then starting at neutral and at park. NO luck so I think my neutral safety switch isn't the issues. Any ideas what I should test next?

Other symptom I had before it died for good was it stalled, tachometer wiggles around, and I saw a battery sign before it died on my last trip when i came to a stop. But I was able to get it to start one last time and make it back home, afterwords, it hasn't started, just a single click from the starter if i am lucky, as it's not getting 12v to start.

I'm thinking BCM/PCM issue, or crankshaft position sensor. any other ideas would be appreciated. My battery was around 12.5 volts which doesn't seem to me to be an alternator charging issues. Not sure if a functioning alternator is needed to start up.

 

battery is weak,do a load test on it.

 

Turned out it was a ground connection. Make sure you have good grounds.