I noticed the RPM guage after you shutdown goes to zero then about 1 to 2 minutes it goes below zero and then bounces back up to zero. Is this normal , what is it doing?

 

wreed! How've you been, buddy? I've never noticed if my tach does this or not. I guess I'm not sitting in the truck that long after a shutdown. I wonder if this has anything to do with the shutoff of interior lights, the reduction in power draw from other components, or similar things?

- Jack

 

Im doing excellent how about you!?

Its almost like it is doing some sort of self test and I believe another member has noticed it before I just dont remember exactly. I might try to read my workshop manuals but that will be like finding a needle in a haystack. I only noticed it while waiting 45 minutes for someone to open a building and I didnt want to idle my truck. I saw it happen so I fired her up and shut it down again and it does it everytime.

see ya...

 

Anyone else ever notice this?

 

I'm not so sure about the RPM going below zero, but mine floats and then reaches above zero, then back down.