battery drain, Is my generator bad? Options

[Tom]

Your testing the alternator with on ohmmeter sounds correct. Diodes will read one way, not the other if they are good. Although this is not a test that proves them good all of the time. They sometimes can break down under load.
Here is what I would do. Charge up the battery , hook everything up like it should be and test the battery voltage when off and when running. Off should be same voltage as battery voltage after charging, on and running should be 13 - 14 volts. If this is good, alternator is probably OK.
Now ( step 1), disconnect the 4 red wires at the + battery terminal and leave overnight. If the battery is good it means you have a drain in your power to the key switch, fuse panel under dash, or relay board. If battery is still bad, ( step 2) disconnect the neg battery post, charge it up and leave overnight. If battery is bad then, you have a bad battery.
If after step 2 the battery is OK, then disconnect the large alternator lead at the starter and insulate it, hook up the battery neg and positive terminals and let it set overnight. If battery now is bad, you have something causing a current draw in the alternator.
Hope this helps get you through this.
Tom

[ruby914]

Your testing the alternator with on ohmmeter sounds correct. Diodes will read one way, not the other if they are good. Although this is not a test that proves them good all of the time. They sometimes can break down under load.
Here is what I would do. Charge up the battery , hook everything up like it should be and test the battery voltage when off and when running. Off should be same voltage as battery voltage after charging, on and running should be 13 - 14 volts. If this is good, alternator is probably OK.
Now ( step 1), disconnect the 4 red wires at the + battery terminal and leave overnight. If the battery is good it means you have a drain in your power to the key switch, fuse panel under dash, or relay board or alternator. If battery is still bad, ( step 2) disconnect the neg battery post, charge it up and leave overnight. If battery is bad then, you have a bad battery.
If after step 2 the battery is OK, then disconnect the large alternator lead at the starter and insulate it, hook up the battery neg and positive terminals and let it set overnight. If battery now is bad, you have something causing a current draw in the alternator.
Hope this helps get you through this.
Tom

Thanks Tom,
Last night the battery was unplugged and it now starts right up.
Ok, Battery is charged with 12v. With car running I get 14.5v.
The one failed test I saw at O'Reiles was an over charge.

The load I read on the multimeter with everything hooked up and with the dial on Rx10, the needle reads 5. I don't know, is that a lot?
Disconnect the alternator and it reads about 30.

The car has 90% Subaru wiring, ECU, and gauge cluster.
The WRX gauge cluster is not showing a charging or battery problem.

The car will sit over night with the alternator unplugged.

[Tom]

The load I read on the multimeter with everything hooked up and with the dial on Rx10, the needle reads 5. I don't know, is that a lot?
Disconnect the alternator and it reads about 30.

Where are you taking this reading? It is 50 ohms and 300 ohms Rx10, so multiply the reading by 10. Quite a difference, but I need to know where and what leads were where. Black lead to ground, red lead to ?. Do this reading with the neg. battery cable disconnected. With everything off, this reading should be high as in lots of ohms. The more the better. 50 ohms to ground will give you 240 miliamps ( 12 volts/50 ohms=0.24 amps) 300 gives you 12/300=0.04 amps). Do you have a clock hooked up? A clock should not run the battery down, however it is good to know when taking readings.
Sounds like maybe you have a drain in the alternator. Is it very dirty? Oil and dirt can combine to form resistance and coat parts in the alternator until you get a path for current to flow, however small.
Tomorrow should give you some answers,
Tom

[ruby914]

The load I read on the multimeter with everything hooked up and with the dial on Rx10, the needle reads 5. I don't know, is that a lot?
Disconnect the alternator and it reads about 30.

Where are you taking this reading? It is 50 ohms and 300 ohms Rx10, so multiply the reading by 10. Quite a difference, but I need to know where and what leads were where. Black lead to ground, red lead to ?. Do this reading with the neg. battery cable disconnected. With everything off, this reading should be high as in lots of ohms. The more the better. 50 ohms to ground will give you 240 miliamps ( 12 volts/50 ohms=0.24 amps) 300 gives you 12/300=0.04 amps). Do you have a clock hooked up? A clock should not run the battery down, however it is good to know when taking readings.
Sounds like maybe you have a drain in the alternator. Is it very dirty? Oil and dirt can combine to form resistance and coat parts in the alternator until you get a path for current to flow, however small.
Tomorrow should give you some answers,
Tom

No clock. Readings were taken between + battery (connected) and- battery lead (disconnected). The alternator seems clean, don't think that is a problem.
I messed up last night and left the - lead disconnected.
Everything is connected now and I will take the other car to work.
I went back and checked the truck the same way and I get the same readings so It seems like all is relatively normal. I will know more when I get home...

[Tom]

I just took readings on mine and I am reading in the megohms with the negative disconnected and everything else hooked up.
Since you are saying you have a lot of the WRX electrics installed, then that is where I would look for the drain on the battery. Sorry I can't help there, no Subaru experience. How are the Subie electrics getting power? Isolate the power to them and take new readings. Lower ohms to ground readings with things off = more current when sitting overnight. In a perfect electrical/electronic system that would be 0 amps. Theoretically possible, but not practical. You will always have a very small current.
By the way, do you get a small spark when hooking up the battery? That is a good indication that you have something drawing current.
Tom

[ruby914]

I just took readings on mine and I am reading in the megohms with the negative disconnected and everything else hooked up.
Since you are saying you have a lot of the WRX electrics installed, then that is where I would look for the drain on the battery. Sorry I can't help there, no Subaru experience. How are the Subie electrics getting power? Isolate the power to them and take new readings. Lower ohms to ground readings with things off = more current when sitting overnight. In a perfect electrical/electronic system that would be 0 amps. Theoretically possible, but not practical. You will always have a very small current.
By the way, do you get a small spark when hooking up the battery? That is a good indication that you have something drawing current.
Tom

Just an update.
Slow to update because my Modem is acting up like my car was.

The car sat for days with every thing hooked up but a door is off and the door ajar light has been on all that time. Car started with out a problem yesterday.
I look forward to get this body work on the door completed and start driving again.

I am hoping it fixed its self because I didn't do anything.
And hope I am not speaking too soon.

Now, I wish my modem and lawnmower would follow the cars example.

[mrholland2]

I just took readings on mine and I am reading in the megohms with the negative disconnected and everything else hooked up.
Since you are saying you have a lot of the WRX electrics installed, then that is where I would look for the drain on the battery. Sorry I can't help there, no Subaru experience. How are the Subie electrics getting power? Isolate the power to them and take new readings. Lower ohms to ground readings with things off = more current when sitting overnight. In a perfect electrical/electronic system that would be 0 amps. Theoretically possible, but not practical. You will always have a very small current.
By the way, do you get a small spark when hooking up the battery? That is a good indication that you have something drawing current.
Tom

Just an update.
Slow to update because my Modem is acting up like my car was.

The car sat for days with every thing hooked up but a door is off and the door ajar light has been on all that time. Car started with out a problem yesterday.
I look forward to get this body work on the door completed and start driving again.

I am hoping it fixed its self because I didn't do anything.
And hope I am not speaking too soon.

Now, I wish my modem and lawnmower would follow the cars example.

Since things don't fix themselves, you should hope that there was a misconnection or a bad connection that you corrected in all the tests etc you did. Otherwise, the problem will return (and, in my past experience, with a vengeance)

[ruby914]

Ok, so they don't fix them selves.
Guess I didn't let it drain long enough.
Got a new Innova 3320 multimeter.
I just have to learn how to use more functions.

I am guessing I don't plug the red meter lead to the 200mA MAX fused receiver?
I use the DC10A receiver?

Now, everything is connected but the - battery cable.
Put the meter on DC10A, one lead to - B terminal the other to - B cable.
I read .250 off the bat but that drops quickly then becomes a very slow decline around .170

Is this reading .25x10 = 2.5A ... bad
or .25A, what I am understanding is not bad?

[Tom]

You don't have to multiply the reading. The DC10A just means that jack will handle up to 10 amps direct current before blowing the internal fuse. 250 miliamps isn't too bad, but it makes me wonder where that much is going. Maybe the Subie ECU?
Tom