My battery keeps dieing and I am not sure if the battery is just past it's life or if there is a load on the circuit.

How do I test this? I have a battery/alternator tester and when I jump the truck and it is running it says that my alternator is cranking just fine. THen I turn the engine off and after a little while I tested the terminals with my multi-meter and the battery read 11volts and it wouldn't trun over.

WHat setting on my meter do I use to test load? the ohm meter? and if so what do I want it to read? 0? if there is anything more than 0, I have load right?

So I assume trouble shooting would just be unhooking things?

Thanks

 

you use the AMP scale on your meter, unhook the positive post, touch one lead to the battery post and the other to the cable, a good number would be 50 milliamps or less, if your over that, start pulling fuses until the load goes away, once you find the fuse thats causing the draw, get out a wiring diagram of the circuits that use that fuse, and then start unplugging the loads on those circuits until you find the culprit

 

DO NOT - DO NOT - DO NOT try to start the truck with the meter in the circuit. In fact, if you use a low scale (like the 50ma range) do NOT even try turning on your lights.

Doing so will overload the meter, and while most meters have fuse protection, a massive overload could easily damage the meter before the fuse has a chance to give way.

The safest thing to do when looking for stray loads like this is to start at the highest range on the meter (usually around 2 amps, unless it has a separate 10 amp "shunted" circuit) and then come down.

You've got more than a 50ma drain going if you can let it set "for a little bit" and it won't start.

Also, remember that there will be a drain from keep-alive circuits like the ECU, clock and radio keep-alive. I don't think those will total to more than 200ma (which won't drain your battery in any reasonable timeframe) but as you pull fuses, remember that hitting 0 isn't necessarily a good thing.

 

Another option is to use a test light (which you can get for cheap at your local parts store) and hook it up pos to gnd. The beauty about the test light is that you will see it get brighter when you unplug (or disable the culprit). I have the same problem right now, and I am starting to suspect my air horn relay.

 

relays hsouldnt be drawing any pwoer if they are not on....

 

unless they are faulty...again, just a hunch. I have a lot of other little things that could be doing it.

 

So a faulty relay might actually make enough contact for draw, but not for operation of it's devices? I have 2 or 3 aftermarket relays I should check those.

SuperJoe, Midiwall- Thanks for the help. I'll try that stuff.

 

I am having the same issue, Now I know what to try.

 

i'm having the same problem, something is drawing enough current to drain a yellow top stone dead overnight, so i have to unplug the battery every time i park the car

 

But deathrunner states his battery is at 11 volts after a "little while". From that I'm assuming within 1 hour. This sounds more like a bad battery to me. For a good starting battery to be pulled down that quickly it would have to be an extremely hefty draw. I'd have the battery load tested before I began pulling fuses. Just my 2 cents...

 

I am pretty sure the battery is fubar, but I want to make sure that it is just an aging battery and not my electrical system before I throw an expensive Optima in and potentially harm it.

 

UPDATE:

So I disconnected the positive and ran my multimeter in series between the post and cable. I used the DCma setting and did not turn the car on. I DID NOT get any reading. It stayed at 0. I feel like I missed something. I was expecting at least 50ma. Did I do it right?

Then I check the battery voltage 11.8 and car would not start or any accessories (Dome light, stereo)

So I jumped the car and it was running. I tested the battery terminal and it said about 12 volts....I then checked a little farther back on the cable and got 14 volts (Is this because of a better contact or is this showing that the alternator is good?)

I tested the system with my batt/alternator checker thing and it said that the alternator was cranking just fine. Then I turned off the car after letting it run for 10 minutes. Nothing...no accessories or starting again. This time the batt was at 11 volts again.

So I take it that the battery is bad, but I still want to know if my system caused this dilemma. Let me know if there is anything I am doing wrong when checkiung for load. I am using an digital multimeter from radio shack (It's yellow and it only has two holes for the test cables, so I know it's hooked up right.)

I really want to figure this out so I don't screw up an optima. Thanks

 

Your best bet is to have the Optima slow charged (which could take a day) and then put it back in and see what happens. That is what Autozone required me to do before they would even entertain the idea that the Red Top was faulty. Turns out the battery held up nicely after the charge, but each day the DCV would go down.

It sounds to me like you have a faulty battery since it dropped all the way to 11 volts.

Where did you buy it?

 

Well to clear things up, I don't have an optima right now. I have one of those green top bastards...the name escapes me. I didn't buy it. When I was having work done at Protrux, my old battery went out, they were nice enough to swap with this battery free of charge. Lasted 8 months so I ain't complaining.

My biggest desire is to verify that it is just this battery (Wose complete lifespan I am unaware of) and not something in my electrical chain.

 

When you were hooked up like this, did the dome light come on? If so, then current was definitely flowing through the meter. If not, then there's something amiss. Maybe a gritty connection on the battery terminal and the meter probe didn't break through it?

Or... the fuse protecting the current measuring side of the meter popped.

Is this an autoranging meter?

 

You should get some small current with everything "off". 10-25 mA is pretty typical, when you get up to about 50mA, you can drain a battery in a few weeks. If the current draw is excessive, then start pulling fuses until it drops. Then the big drain is in the circuit you last disconnected.

 

it is an autoranging meter, I think I got okay contact because I was able to read ohmage and voltage from the same points.

Everythings was off, but there isn't even enough juice in my battery to make the doem light glow.

 

bump.... I wish this wasn't moved to maintenance, I don't think any one actually checks in here.

 

you gotta bad connection in your battery!check it with another.

 

a bad connection inside the battery> or between the terminals and studs?