speedo moves while in park

[jerkyboyxiii]

WTFO? started up the ranger tonight and watched the speedometer climbing to about 15mph and dropping to 5mph. I was in Park. I drove it a couple of blocks and the Theft light flickered and went away. I got to my destination a few miles later, and I watched the batt light flickering. I revved the engine and watched the batt light go away, only to flicker again while idling. Whaddya all think???

 

[txsleds]

Please check your battery for clean, well secured battery cables. Check the connection for the battery GROUND. Check the engine grounding strap to the firewall.
Have your battery and alternator load tested. Thank you for your service. U.S. Navy (Retired)
Two great videos here:

 

[rubydist]

Stop watching Back to the Future??


Seriously, it does sound like a ground issue somewhere.

 

[jerkyboyxiii]

Please check your battery for clean, well secured battery cables. Check the connection for the battery GROUND. Check the engine grounding strap to the firewall.
Have your battery and alternator load tested. Thank you for your service. U.S. Navy (Retired)
Two great videos here:

i have a pretty healthy sound system thats gunna be installed soon. I just ordered a 200 amp alternator. Ill see if this corrects the problem. If not, ill start chasing grounds.