Battery draining with switch off

Theone4eva · Post by **Theone4eva** » 06 Jul 2018, 11:39

I have a 2006 S80 2.5t that was purchased after an engine swap. Ran well for a few weeks, then started having to get a jump every time I turned it off. Checked all fuses and connections found only one not connected (may be a topic for a later post). My question is does the CEM drain power while the switch is off if it needs to be sent to Xemodex for repair? I've used them before on an 04 S80 and like them. Or, is there some other issue that I need to familiarize myself with?

Post by **RickHaleParker** » 06 Jul 2018, 12:13

You need to jump start every time you turn it off. Sounds like the battery is shot or the alternator is not fully charging it.

Theone4eva · Post by **Theone4eva** » 06 Jul 2018, 12:52

From what I can tell, two batteries later, the alternator has been tested and is charging. Something is causing the dash to continue to display info after shut-off and key removal. The maintenance required warning in the info center can be turned off with the read button but it continues to pull after that.

Post by **SuperHerman** » 06 Jul 2018, 15:30

You need to pull fuses and measure current draw until you find the offending circuit drain. Do a search and you will find videos on the process - pretty straight forward.

Once you have the offending circuit isolated report back and it will be easier to help you trouble shoot. You could have a bad relay, alternator, shunt, ground or connection (or a bad CEM), but until you do some more digging you are throwing darts.