91Bird305

Should the ARC fuse be drawing any amps when the car is shut off? I am troubleshooting a small drain on the battery (.4 amp drain) and I ran across .2 amps on the ARC fuse.

I believe this fuse is for the radio?

Thanks.

kcallais

Refresh my memory....ARC?

NINÅ

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91Bird305

I can't tell where your anwser ends.

Anyways, yes, it's the radio. So what would cause the radio to draw that many amps?

MI ROC-Z

Im wondering if this is what might be going on with my car. The battery seems to drain after about 5-6 days of it being parked. Is the ARC fuse located in the fuse panel area, engine compartment, or withing the radio wiring?

91Bird305

Fuse panel.

NINÅ

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Fullsizewagon

Please observe and get a grip on the correct denominators (or whatever it's called)..
.4 Amps (= 400 milliAmps) will completely drain a fully charged battery in 5-6 days.
If you have the DMM set to the 200mA range and get a reading of .2 then that is .2 milliAmps or 200 microAmps, a common value for radio memory backup.
.2 Amps is the kind of current a relay or one or two signal lamps would be drawing.

91Bird305

Ok, so .2 milliAmps is a normal draw on the battery?

Cause I am getting a total of .4 milliAmps then. I am not sure where the other .2 is coming from, but I know the .2 I found was off the ARC fuse. I haven't found the other .2 yet but I have a good guess that it might be coming from an electric cut out.

Now I had someone tell me today that the headlamp motor module is also off this fuse. Is that correct?

Fullsizewagon

Yes, .4mA is a perfectly normal drain, .2mA from the radio and the other .2mA from a clock, or the thing that goes ding maybe.
I have a newer radio that draws 20mA. That'll drain my battery in 4 months. Not good with the car sitting so I yank the radio in the winter.
Now, please tell us the symptoms that has lead you to chase a drain.

91Bird305

Battery drain after sitting for a month.

I just didn't think a battery could drain almost dead if it isn't charged for a month. I thought it was odd, then found the .4mA on the battery and tried tracking it down. But I guess .4mA is normal? So any thirdgen that sits for a month will probably have a dead battery?

Fullsizewagon

If your battery has full capacity (certainly not certain) then you're looking at a draw of around 80mA. That's 1W (or a real small lamp). Try to start measuring at the battery itself. Pull the negative post and measure across there. If no significant draw there then the battery has developed a high internal self-discharge. That can happen just from old age or by it being emptied too far once too many.
If you do find a draw then proceed with the positive post on the alternator, before searching further into the electrical system.
A normal battery (& car) should be able to survive a year in storage and still have some power left, although it's generally recommended to recharge their batteries 2-4 times a year. The colder it is the longer it can sit w/o a recharge.
.4mA will by itself require 17 years to drain a battery.

MI ROC-Z

This post is exactly what I was looking for. Im trying to determine how the battery in my car keeps dying after 5-6 days of sitting in the garage. While driving I observe that the amps are between 12-14 on the stock gauge, which I thought was normal. It will fire right up every time and seems to be getting enough spark.

I want to remove the old alarm system on the car. Is this a job I should take on or leave it to an alarm shop to remove. The problem I have is that when I start the car the doors lock, and the stock door lock/unlock will not function.

I know I have a gremlin somewhere and its getting on my last nerve!

Any ideas or suggestions?

Fullsizewagon

Alarm systems are sometimes more of a nuisance to their owner than to a thief..
I take it you have no DVM to measure current draw with, and that leaving the negative battery post off keeps the charge in the battery. Next test could be to remove all fuses, relays, & connectors belonging to the alarm system and see if that makes the battery hold. A quicker way would be if you had a test lamp; it can also be used to trace a current draw.
If you know how to properly splice wires then it's not a big deal to remove an alarm system. You'll most certainly have to dig into taped-over wiring, find the ends of any cut wires and splice them like they were originally. Nothing more to it.

91Bird305

FYI, I checked the multimeter again today and I was right. .2 amps (or 200 milliamps) at the ARC fuse and .4 amps (400 milliAmps) at the battery.

So what else is on the ARC fuse that would be drawing 200 milliAmps besides the radio? It has to be used for something else. Someone mentioned that it looks like the headlamp motor module is also on that and it could be a headlamp door controller issue.

Thoughts?

RED_DRAGON_85

i dont know, but i can sit for a few months and not hurt the battery at all.
not that it has sat for a long time, i drive it every day, but in the process of getting it reliable, it sat for a long time.

fwiw, i get next to zero draw on the ARC fuse with a digital VOM
i have a aftermarket radio but i have it set up to have the clock off when the car is off.
that might be part of why i have no real draw.
the only draw the radio should have is to keep the flash memory programmed, which requires next to nothing IIRC.

lets just say that you should be able to sit for at least a month without putting a dent in the battery.

NINÅ

Also, the keep in mind correct abbreviation is uA for micro amps.

91Bird305

ok, well you get the idea of what is happening. The radio is drawing way to much. I removed the fuse but obviously there is still a .2 drain somewhere.

Any idea why the radio would draw so much?

Fullsizewagon

I found the wiring diagrams on the net and it seems the ARC 20A fuse only supplies the radio memory backup, so then the radio must have a fault in it somewhere if it really draws 200mA, unless someone has hooked something else to that orange wire.
As for the other 200mA you'll just have to pull things and see. Cargo or glove compartment lamps maybe?
Remember 200mA is 2.4W of power and the offender will be warm to the touch.

As for microAmps, a common and acceptable way of abbreviating it is uA, although the technical abbreviation is the Greek letter mu - but try to find that on your keyboard.. The reason I stress using correct denomitators is that people are too much confused about electricity as it is - so I do get nitty-gritty. I don't know why, but Americans in general seems to have a hard time about the use of small and big letters too; mW means milliWatts but MW means MegaWatts - for instance.

NINÅ

Quote:

the Greek letter mu - try to find that on your keyboard

I couldn’t. So I took a sharpie and drew it on my ‘U’ key.

How’s it look?
μ

Fullsizewagon

Hey, that's great! I knew there was a way, thanks for drawing it out for me, now I can just copy & paste it! (Clever smart a**!) Hehe, no offense..

91Bird305 - please let us know how it goes..
You're not alone you know, here's a similar issue.