[SOLVED] Parasitic current on a 2004 Sienna

Is there a light that goes on under the hood when it's opened?

No, there is no light under the hood. I even went out in the dark garage at night to see if there was a small light on anywhere such as vanity lights behind mirrors, lights in glove boxes, or under the hood, back hatch, lower doors, etc. Remember, it is not a failure in my van, because my daughter's van has the same parasitic current drain. When I first connect the ammeter, the current starts at about 350ma, then steps down to 220 after about 10 to

15 seconds. I suspect this is the various computers initializing after a power on. If I turn on one light over the driver's side, the current will go up by about 340ma. I have a shop manual for the van, but it does not address this. It would only become an issue if you had a battery going down over time, and needed to know if it was a bad battery or the parasitic current drain. I replaced the battery, so it may be fixed. I am only looking further because the dealer said my 220ma current is too high. Charles Ranheim.

By any chance, do you have any aftermarket accessories like an aftermarket audio system, remote starter, security system, etc.?

If the van has automatic headlights, see if the parasitic draw goes down with the headlight switch in the off position.

Ray O I do not have any aftermarket accessories, and my headlight switch is in the off position. I cannot be anything unique to my van because, as I stated in the previous post, my daughter's 2004 Sienna has the same readings. I wish I could get the actual spec on this from Toyota, but that would be impossible. Thanks for your interest. Charles Ranheim

Not sure if you'll take this seriously, but I'd go to

get the phone number for the PBS radio show, and see if you can talk to the two nutty, but very knowledgable guys who answer car questions. I don't know how they select who they'll call back, but if it's partially based on a question being unique, you've got a real winner.

I do no know if those guys actually do research before providing answers, but I've seen some pretty poor responses.

From my experience fixing problem cars, I have learned to never assume anything. For example, it is possible that you and your daughter have the same aftermarket remote starter because you recommended it to other or vice versa.

25 to 60 milliamps used to be the "conventional wisdom" for acceptable parasitic draw, but modern vehicles have more systems that draw current with the vehicle shut off, and a little here and a little there start to add up, although I don't know if it adds up to 220 mA. Some systems are on timers, like the retained power for power windows, auto off headlights, and passive restraint systems. The stuff that is always hot are the powertrain electronic control module (ECU), clock, radio memory, security system ECU, and rear power door ECU (if equipped with power sliding door or hatchback).

And I've heard some excellent ones. It's always worth consulting another source, especially since the dealer seems clueless about this.

ROFLMAO.....

How could you question Joe 'the legend in his own mind'?

Ray O

I purchased my Sienna LE new, so I know I don't have any OEM attachments. My daughter bought her Sienna CE used. I have more options on my LE, but apparently none of these draw extra parasitic current. Charles Ranheim

I assume you have long lists of examples where the guys on the radio were wrong.

I'm curious, what is your setup for measuring current draw. What kind of meter, I know it's an ammeter, but the make, model ect. External shunt perhaps? Where did you tap in, at the battery post? I also have a

04 Sienna and it has a security system that as soon as I lock the door it's activated along with a blinking LED on the dash.

I personally would not feel comfortable getting advice or doing business with guys that name their company Dewey, Cheetham, & Howe. I will give them credit for doing research - they used to call our office or the local Toyota dealer for advice when someone had a question on a Toyota, and my boss at the time was a guest on their show.

Back to the OP - I am pretty sure that the normal parasitic draw is listed somewhere, I'll try to do a little research when I get home.

That is good information to have, I'll try to remember to do a little research when I get home. I've been thinking about this post for a while, it is good exercise for the brain.

In the meantime, if you are curious as to which circuits are drawing current, with the ammeter still rigged, pull 1 fuse at a time and watch to see how much the current changes, if at all, for each fuse pulled.

dbu, I used a Precision analog multimeter and a Fluke digital multimeter. I use their normal internal shunts because the current I am testing for is under an amp. I start out my making sure everything is turned off, and the doors are shut so all lights will be off. I then remove the positive battery cable and set it aside. Now, for the test, I connect the meter, which is set to the current range, between the removed positive battery cable and the positive battery post. You will now see the parasitic current draw from the battery. Do not turn anything on or open a door that might increase the current to the point it will damage your meter. Most multimeters have a low maximum current range. My digital Fluke has a maximum range of 2 amps (2000ma). My analog meter will handle 12 amps. I used that one first to make sure I did not exceed the 2amp spec on my Fluke. External shunts would be used to measure high currents. If you are not familiar with doing this, don't do it. You might burn out your meter, or at least blow the protective fuse it it. I am beginning to think the 25 to 60ma spec given me is a spec for most cars, and may not apply to my Sienna. Charles Ranheim

"dbu," wrote in message news: snipped-for-privacy@comcast.dca.giganews.com...

Ok, thanks. I have a Fluke 77 and some other multimeters, 260 ect. When the wx warms up I'd like to measure mine also and see what the current draw is. I often wondered about that because of the security system. I have left the Sienna in the garage for several days without use and never once has the battery come up dead. Could a leaky diode in the alternator cause excessive draw, just a thought.

dbu, Keep in mind my daughter's 2004 Sienna has the same readings. Certainly we don't both have the same problem. Because of that, I am not treating it as a problem with my van at this time. I am hoping my new battery will solve the starting problem. Thanks for your interest.

Post what you find. I am interested. This is about as exciting as it gets with the Sienna.

I looked in my factory repair manuals and was not able to find a specification for parasitic current draw.

My guess agrees with yours, that it is unlikely that both your van and your daughter's van would have the same problem.

Sorry I couldn't provide more useful information.