Strange Electrical Issues with my 2015 S60 T6

postrecords · Post by **postrecords** » 30 Mar 2021, 18:01

A few days ago, after using the car all day long with no issues, I parked and noticed the car would no lock using the remote key. I checked the interior and car power was totally off...no lights, nothing at all. I had to lock it manually using the key.

I was headed into a restaurant so I ate and came out expecting to call roadside assistance but the car suddenly had power again and started up for me. I got home, turned off the car and again no power, wouldn't lock etc.

I checked the battery...12.6v, showing charged as well. I disconnected and reconnected the battery and the car started.

I've had the same issue again multiple times in the last couple days. It seems to work when I disconnect and reconnect the battery but other than that the car will have no power, can't jump start it, etc.

Not sure if this is related but I noticed the vent tube coming out of the battery does not appear to be connected anywhere on the car...the little right angle on the tube is connected to the battery, then the tube just hangs there.

pbierre · Post by **pbierre** » 30 Mar 2021, 21:36

The vent hose on the battery wouldn't be related.

This sounds like some motor or solenoid is "sticky" and drawing big current during and right-after shut-down, enough to pull down the battery voltage below 12Vdc, killing all the computer modules. After a period of time, the power to it is cut by a timer. That explains how the battery voltage springs back up enough to start.

Suggest you find a quiet place, and shut down the engine and raise the hood. Have the battery box outer cover removed, ready to slap a voltmeter on (to 12V connector, and any ground point on engine. You're listening for any sounds of motors that are hanging over, and monitoring the battery voltage until it jumps up.

postrecords · Post by **postrecords** » 31 Mar 2021, 11:13

Thank you. I did figure out where the vent hose connects to the grommet (duh)...and as you noted, that did not fix the problem.

I have noticed sometimes when I turn the car off recently, I'll lock it and I hear a clicking noise that does kind of sound like an electrical switch sound. No idea what it is...seems to be coming from around the driver side near the front wheel well. Thanks for the tips on troubleshooting though!