I'm a proud owner of an 05 MCS. However its been acting up on me recently. Over the past couple days, I've been losing power when backing into my driveway. Its late so my lights, stereo and A/C are on. Then when I cut the wheel all the way- Wham! electrical failure. The engine keeps running, but its like I've disconnected my battery. I lose my time and trip meter resets, power steering is dead for a few seconds, and then after straightening out all my guages come back on.... I thought it was maybe an issue with the power steering but last night after starting I turned on the headlights only to see them start to rapidly flicker. I turn them off then on, and then back to normal. The battery's LED was not lit up, leading me to believe it was dead.

So just now I take it to Autozone where they test it... of course it is fully charged...

The only thing I can think of is that I drove to Autozone, no A/C, lights or stereo, and the battery was able to charge.

Any ideas!?!

 

Possibly a bad ground connection, which is affected by some movement of the wheels?

 

I've heard these steering pumps draw a lot of power... I assume that turning all the way would make it draw more power leading to power failure...

One other possibly related issue... Does anyone's car at rest or low speed make a WuuuWuuuuWuuuu sound? Mine seems to do this until at speed.

 

Could be that the alternator isn't putting out enough current and the voltage is dropping while under load. You could try checking voltage at the battery when running without accesories, and then again with the brights and the rest of the works, if you see a big drop in voltage with them on it's a good possibility. It's a bit early for brushes in the alternator to wear out, but one could have built up some carbon, or maybe a diode going out?

Also, did they test the battery under load, or just with a voltage meter? Sometimes they'll look okay until you try to pull more than a little current.

 

I'm thinking its the alternator or maybe the sepentine belt?

They tested it with car off, and after I drove it w/o accessories.

 

Sounds like a battery issue to me too - but it might simply be poor connections between battery and car.
Check the connections on the battery terminals, and check where the battery neg bolts on to the car chassis.

 

check the battery with the car not running. then with it running ; you should see a 2 volt increase . if not then your not charging well . or if you take frequent short trips and don't trickle charge the battery in between ; it may just need a good run on the highway .

 

I have the similar problems affects , horn,p/strg,gauges, the dealer has had the car 1 week doesnt know , BUT PROBABLY NOT WARRANTY !! due to the fact it has had a rear collision previous? SO WHAT !!
If you find a cure please pass it on thnx.