somethings draining my battery
Test it properly in DC. Wait about a minute for everything to settle. Anything above approximately 20mA is unacceptable. As stated earlier, 150-200mA draw is going to indicate a single stuck relay.
I pulled a RS/alarm from a customer's E36 last week which had failed and was drawing 700mA! So if the alarm is poorly installed or nearly as old as the car it's definitely a possibility for issue.
I pulled a RS/alarm from a customer's E36 last week which had failed and was drawing 700mA! So if the alarm is poorly installed or nearly as old as the car it's definitely a possibility for issue.
Thread Starter
Insane Stance and Offset
Joined: Feb 2013
Posts: 214
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From: Seymour Johnson Air Force Base, NC
Test it properly in DC. Wait about a minute for everything to settle. Anything above approximately 20mA is unacceptable. As stated earlier, 150-200mA draw is going to indicate a single stuck relay.
I pulled a RS/alarm from a customer's E36 last week which had failed and was drawing 700mA! So if the alarm is poorly installed or nearly as old as the car it's definitely a possibility for issue.
I pulled a RS/alarm from a customer's E36 last week which had failed and was drawing 700mA! So if the alarm is poorly installed or nearly as old as the car it's definitely a possibility for issue.
ok. so here is the process of what im going to do if im understanding correctly. disconnect the positive pattery terminal. then let it sit for a minute or so. turn my multimeter to DCma. hold one end to the post on the battery itself, and then the other lead to the red terminal connector. get reading. then repost...
ok. so here is the process of what im going to do if im understanding correctly. disconnect the positive pattery terminal. then let it sit for a minute or so. turn my multimeter to DCma. hold one end to the post on the battery itself, and then the other lead to the red terminal connector. get reading. then repost...
Thread Starter
Insane Stance and Offset
Joined: Feb 2013
Posts: 214
Likes: 0
From: Seymour Johnson Air Force Base, NC
the picture is showing that i do the test on the negative terminal, but i was told earlier its tested on the positive. i appreciate the diagram but im now more lost haha
Please explain why?
I did a quick google search, because i was curious and this is basically all I found.
"Polarity doesn't matter. Modern multimeters auto range and sense current, and will display correctly."
I know my multimeter doesn't show "negative" current draw when I got my leads switched up.
I did a quick google search, because i was curious and this is basically all I found.
"Polarity doesn't matter. Modern multimeters auto range and sense current, and will display correctly."
I know my multimeter doesn't show "negative" current draw when I got my leads switched up.
Joined: Oct 2003
Posts: 1,600
Likes: 49
From: Norcal/Bay Area, CA
I've had a battery with a bad cell. It would hold 12.5V overnight. It'd try to start and before it made a full revolution, it wouldn't trigger the main relay any more. Suddenly down to 11v.
On a side note: It was a 100 month Acura battery on a 6 year old car. They said there's no proof it was the original battery. I asked him if he wanted a reciept from the time I paid someone not to change the battery. He was not amused.
Good advice. But if you have access to the fuses, why not just touch the multimeter leads to the fuse holder?
On a side note: It was a 100 month Acura battery on a 6 year old car. They said there's no proof it was the original battery. I asked him if he wanted a reciept from the time I paid someone not to change the battery. He was not amused.
Good advice. But if you have access to the fuses, why not just touch the multimeter leads to the fuse holder?
The reason I remember when being trained to be a mechanic(back in the '60's), it is safer and vitually everthing electrical in the car had to return via the negative cable(believe it or not, there are some exceptions to the "it's the same thing on the positive side" argument, even though with our cars it should not make a difference).
I've had a battery with a bad cell. It would hold 12.5V overnight. It'd try to start and before it made a full revolution, it wouldn't trigger the main relay any more. Suddenly down to 11v.
On a side note: It was a 100 month Acura battery on a 6 year old car. They said there's no proof it was the original battery. I asked him if he wanted a reciept from the time I paid someone not to change the battery. He was not amused.
Good advice. But if you have access to the fuses, why not just touch the multimeter leads to the fuse holder?
On a side note: It was a 100 month Acura battery on a 6 year old car. They said there's no proof it was the original battery. I asked him if he wanted a reciept from the time I paid someone not to change the battery. He was not amused.
Good advice. But if you have access to the fuses, why not just touch the multimeter leads to the fuse holder?
The first step is to set the multimeter in series with a batt cable, and the second step is to start pulling fuses, one at a time, till the numbers drop.
Joined: Oct 2003
Posts: 1,600
Likes: 49
From: Norcal/Bay Area, CA
I was doing this for the interior fuse box once. It was much faster to test each fuse for a reading than pulling one and walking back up to the battery at the front of the car to look for a drop.
What was your current-draw?
I've got an 11 year Red Top that O'Reilly's says has a bad cell...it still fires right up, even after a week or two of sitting (when I ride my motorcycle).
Only thing you can do is, charge it as much as you can and then let it rest. After about an hopur, throw your meter on it and see if you have close to 12.6 or single dead cell voltage of 10.5-12.2.
Yes, I have seen bad cells still produce voltage, but not enough to keep the bat 12.6.
Hard to diagnose dead cells on those batteries, can't open them up.
Only thing you can do is, charge it as much as you can and then let it rest. After about an hopur, throw your meter on it and see if you have close to 12.6 or single dead cell voltage of 10.5-12.2.
Yes, I have seen bad cells still produce voltage, but not enough to keep the bat 12.6.
Only thing you can do is, charge it as much as you can and then let it rest. After about an hopur, throw your meter on it and see if you have close to 12.6 or single dead cell voltage of 10.5-12.2.
Yes, I have seen bad cells still produce voltage, but not enough to keep the bat 12.6.
It's also not the process that's been described several times. Seeing as he measured current draw incorrectly once already, I was interested how he concluded the cells were dead. Maybe they're not dead and the battery he has in it now is barely able to keep up with the draw on his system.





