jaa Premium Member join:2000-06-13 |
jaa
Premium Member
2012-Nov-22 10:21 am
Electrical Drain 2008 Toyota SiennaHaving trouble with my Sienna - dead battery. I disconnected it, and see a drain when I don't think there should be any. My meter only goes to 300ma, but it pegs the needle when I touch the leads. There are 3 fuse boxes - one under the hood, one under the driver dash, and one behind the glove box. I found that if I remove the shunt marked "short" in the engine compartment panel, the load goes off. Thinking that went to another fuse panel, I removed all the fuses from the driver's compartment - still have the load. Behind the glove box there is only one fuse. When the shunt is in, the interior lights on the car come on, even with all the fuses removed from the driver's compartment and behind the glove box. If the shunt is out, they are off. Doors closed, all lights in the car are off - but still have the load. Any ideas? Pictures are showing where the shunt is - amp meter test lead points to it. |
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Vchat20Landing is the REAL challenge Premium Member join:2003-09-16 Columbus, OH |
Vchat20
Premium Member
2012-Nov-22 12:19 pm
Quick question: Was there a problem related to said drain that caused you to seek this out?
With all the fuse pulling and whatnot, do you let the car sit for at least an hour or two before reading the load? With most modern cars, a lot of electronics remain active for a short time after the car is off and vacated and eventually settle down. |
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jaa Premium Member join:2000-06-13 |
jaa
Premium Member
2012-Nov-22 12:51 pm
Dead battery was the issue that started all this.
Cleaned the very dirty contacts.
I put it on a charger - I'll let it sit overnight, and see what happens. You may be right - it may be nothing. |
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dandeman MVM join:2001-12-05 Chapel Hill, NC 1 edit |
to jaa
50ma is the maximum expected idle current limit Toyota has published for most (don't know if all) Toyota vehicles.. The attached chart shows the draw on my 2000 4Runner.. Disregard the table for the 2nd battery.. (I have dual batteries, with the second one to handle loads for added equipment..) Note on this vehicle and many, the driver door light switch is used to bring the various computers out of sleep mode.. I found this out the hard way when I left that door open overnight in the garage (with dome lights turned off) to allow a fan to blow air on the carpet that water had been spilled on. That draw was enough to pull the battery down overnight.. Other open doors (even with dome light off) affect idle current draw, as apparently the security computer is coming out of sleep mode.. The driver's door brings the main engine computer out of sleep mode, as I've noticed when opening this door, I can hear the computer prepositioning the throttle IAC valve in preparation for start. |
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Doctor OldsI Need A Remedy For What's Ailing Me. Premium Member join:2001-04-19 1970 442 W30 |
to jaa
If you have a lighter look inside it for a failed lighter element (coil broken off the lighter plug end) and stuck in the lighter socket or check for a stray coin that may have been dropped into the lighter socket. |
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jaa Premium Member join:2000-06-13 |
jaa
Premium Member
2012-Nov-22 7:50 pm
Thanks; it looks like I am well over the 50ma.
Put it on a charger overnight - we'll see what happens.
I wish I knew what loads were attached to that shunt besides the dome lights - how is it possible that the dome lights are not on a fuse? |
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As Vchat20 said, you need to wait for the hour before measuring your parasitic draw. After the hour, make the measurement, but make sure that the ammeter prevents the circuit between the battery post and negative cable from being broken. (or you have to start over again.
Have you double checked all interior lights?
Rest assured, the dome lights ARE on a fuse. Your owners manual contains basic information on what fuses feed what items.
Do you have ANY aftermarket items installed in the vehicle? Are any systems or functions not operating properly?
Add: Wiring diagrams are available at www.techinfo.toyota.com. They have short term subscriptions available. |
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Cho Baka |
to Doctor Olds
said by Doctor Olds:If you have a lighter look inside it for a failed lighter element (coil broken off the lighter plug end) and stuck in the lighter socket or check for a stray coin that may have been dropped into the lighter socket. The lighter or accessory socket on Toyota vehicles is not energized with the key off. |
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jaa Premium Member join:2000-06-13 |
to Cho Baka
I may have to get a better meter - mine only reads up to 300ma. Then I could leave the meter in the circuit.
I will see what happens after charging the battery overnight. My plan is to just take off the charger, and see if the battery goes dead again.
If it dies, I figure either the battery is no good or there is a load that should not be there. Then my dilemma is to buy a new battery or a better meter.... |
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jaa |
jaa
Premium Member
2012-Nov-25 9:57 pm
After charging overnight, the car would not start. Bought a battery to replace the original 2006 battery. Will put it in tomorrow - figured it couldn't hurt to replace a 6-year-old battery.
See if that resolves the issue. |
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to jaa
Does your meter have a 10 amp option? If so you shouldn't need a new meter. my fluke has a 10 amp and 200ma options.
The best way for checking circuits for a draw is to do a voltage drop across the fusses rather than pulling the fusses. Pulling the fuss can lead you to wrong places to look and could also power up modules which you don't want. You don't disconnect the battery at all when doing the voltage drop so there isn't a risk of powering a module up. |
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