Originally Posted by fishtrap
Started with the speedometer not working or flickering. Then replaced 12v battery. The 144v battery has beed disconnected a while. I found one ground wire loose but still something is wrong. The 12v battery has now run down! Anyone have any guesses, because I'm at a loss here.
Recharge your 12V battery in the meantime; Check terminal connections to the 12V battery that all are shiny. Use steel wool if req. to clean if oxidized. Careful of arcing.
Make sure good grounds to vehicle as you've mentioned. ..has the BCM been disconnected or just the IMA switch under the cover been turned off.?
To run without the ima system and still charge the battery : search "bcm disconnect" as keywords to see the two plugs that need be removed from the battery control module, hopefully that should bring up the recent thread.