12V Aux Battery Drain

boom27 · 02-25-2008, 08:58 AM

Hi,

I have a 2004 Prius. It was side swiped while parked. The driver side front fender and front bumper had to be replaced. I have received the car back from the body shop. The radio now cuts in and out when hitting a bump and the 12V aux battery is being drained overnight (nothing was left on). Any recommendations on where to start checking for the problem? I will take it back to the body shop but wanted to give them some insight.

TIA

Boom27

tochatihu · 02-25-2008, 10:33 PM

Are you or they are up to making millamp current measurements when the car is off?

Before you put your meter in series, jumper around it because when you complete the circuit there is a big inrush (and visible spark). This has cost a few meter fuses for your predecessors, myself included, if skip the jumper part

.

Now, with all light bulbs etc. off, you should see about 30 milliamps typical with a few higher peaks. If your Prius has that SKS switchoff thing, it will cause a decrease.

If you are seeing steady drain very much above 50 milliamps, something is amiss. The only clue where to start looking is in the vicinity or your damage area. A wild guess might be that one of the door close switches is not being pushed in completely now.

No idea on the radio thing, but maybe when you get the 12 v sorted out, it will stop happening.

02-25-2008, 08:58 AM	#1
boom27 Junior Member Join Date: Apr 2004 Posts: 3 My Car: Package: Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 0	12V Aux Battery Drain - when off Hi, I have a 2004 Prius. It was side swiped while parked. The driver side front fender and front bumper had to be replaced. I have received the car back from the body shop. The radio now cuts in and out when hitting a bump and the 12V aux battery is being drained overnight (nothing was left on). Any recommendations on where to start checking for the problem? I will take it back to the body shop but wanted to give them some insight. TIA Boom27

02-25-2008, 10:33 PM	#2
tochatihu Senior Member Join Date: Apr 2004 Location: Kunming Yunnan China Posts: 1,817 My Car: 2001 Prius Package: Pioneer #1 Nominated 0 Times in 0 Posts TOTM Awards: 0 Friends: 7	Re: 12V Aux Battery Drain - when off Are you or they are up to making millamp current measurements when the car is off? Before you put your meter in series, jumper around it because when you complete the circuit there is a big inrush (and visible spark). This has cost a few meter fuses for your predecessors, myself included, if skip the jumper part . Now, with all light bulbs etc. off, you should see about 30 milliamps typical with a few higher peaks. If your Prius has that SKS switchoff thing, it will cause a decrease. If you are seeing steady drain very much above 50 milliamps, something is amiss. The only clue where to start looking is in the vicinity or your damage area. A wild guess might be that one of the door close switches is not being pushed in completely now. No idea on the radio thing, but maybe when you get the 12 v sorted out, it will stop happening. __________________ DAS Tochatihu, the Hopi hummingbird kachina