Battery drain

[rjbaren]

Hello guys.  Here is a new problem.  I hadn't driven the car for about 10 days and when I went to start it the battery was dead, wouldn't even light a test light.  It was replaced under warranty.  8 days later it was dead again and wouldn't light a test light.
I replaced it again and they said I have a drain that needs to be addressed and they will not replace the battery again.  I have installed a disconnect at the negative post so I guess I am covered but I still have a problem I would like to address.

I put a digital volt meter from the negative post to the disconnected negative cable it reads 12.8 volts.  I have pulled each fuse in turn, 10 in total, and the voltage reading doesn't change.  I replaced the horn relay as it was clicking when I tried to jump the dead battery but nothing changed and the horn works. 
I have four new relays. One for the high beams, one for the low beams, one for the horn, and one for the radiator fan that also has an over ride switch.  All are relays hot with the key off but are protected by an inline fuse in their power supply.     
Any suggestions?   

[Pfreen]

Disconnect the positive lead from the battery and use a multimeter to measure the resistance in ohms between the positive lead and the negative of the battery.  Ideally, it should be greater than a megaohm.  If not, (in the low kilo-ohm range),  you need to track down what is pulling down the battery and lowering the resistance.  In my case, it was an aftermarket alternator where the voltage sense was leaking current and flattening the battery.   This method found it.
Good luck

[jbcollier]

Does your digital multimeter have a DC amps setting?  If so, how many amps will it read to?

Please don't do anything yet.  Just want to know what you have before giving advice.

[rjbaren]

I have three multimeters.  Of those, two are at home, I will pick up and bring home the third later today.  I don't remember what kind it even is.

I have not done any testing with the positive battery cable or post. Nor have I tested the alternator.

1 meter is analogue & it has milliamps.  It also has DC voltage, Ohms resistance, & AC voltage
 
The other meter is digital.  It is an inexpensive one from Harbor Freight and it has DC amps.  It measures 200u, 2000u, 20m, and 200m, (which I think are milliamps).  There is also a separate 10A input for the red positive lead that reads, 10ADC 10A max.
 
I have been testing the negative side with 20 DCV section only.

[jbcollier]

The meter reading to 10 amps will do the job.  You also need a test light with an incandescent bulb, not LEDs.

It is very important that you are VERY careful with how you hook up an ammeter.  It is a dead-short through the meter when set to amps.  Things can get exciting if you are not careful.

Charge up the battery.  Keys out and put somewhere safe.  All switches off.  Make sure the window switches aren't sticking.

First open everything up: bonnet, engine cover and both doors.  Use duct tape to hold the door switch plungers in.  Now you can access everything without turning anything on.

Disconnect the negative battery terminal.  Hook up the test light from the battery negative post to the battery negative cable.  Does it glow dimly?  Or, super-bright?

TEST LIGHT GLOWS DIMLY:

- disconnect the test light and now attach then ammeter on the 10 amp scale between the negative battery post and the negative battery cable.  Anything over 80-ish milliamps (0.080 amps) is not good.

- I always start at the alternator.  Temporarily disconnect the ammeter.  Disconnect the wires to the alternator and insulate the bare cable ends.  Hook the ammeter back up.  The reading now should not be more than 20 or so milliamps.  Good now?  Your alternator has a bad diode, replace it.  Not the issue?  Disconnect the ammeter and hook the alt back up.

- use the wiring diagram and check all circuits fed by either brown (unfused power) and purple (fused power) wires.  Just follow the circuits and disconnect the wires or pull fuses to isolate the problem.

Common issues:  interior light, window switches, battery fed relays, etc.

Are there aftermarket extras?  Clock or radio, for example?  Check those as well.

TEST LIGHT GLOWS BRIGHTLY:

We do not want to hook up until we get a better handle on how much current is flowing.  Make up a test light using a headlight bulb with wires and alligator clips.  Hook that between the negative battery post and the negative battery cable.  If it glows dimly, then you can hook up your ammeter on the 10 amp scale and proceed as above.  If it glows brightly, then follow the above procedures until find the problem and the headlight bulb test light either stops being bright or doesn't light at all.

[rjbaren]

Ok, I will start testing pretty soon.  I just want to be clear, when you say ammeter you are NOT referring to the gauge in the dash, you are referring to my digital Volt Meter set on amps.
I do have a headlight test rig from prior conversations here testing some circuits.

[jbcollier]

Yes, ammeter setting on your multimeter.

[rjbaren]

Yeah thanks.  Pretty dumb question on my part.
Anyway, with a test light I was getting a flash like every second.  The light was dim when it flashed.  Putting the DVM to the 10 amp setting I got zeros testing just the battery cable.  I then changed the DVM to 200Ma and plugged the red lead into the other input and got a 1.4 reading. 
I next went to the alternator test and I got a .32 reading and then it went down to zero.  I changed it again to the 200Ma setting and I still got zeros.  From that point forward all my readings were at zero.  I pulled every fuse but it started at zero and stayed at zero.  So I am not sure what is happening.  I did change the horn relay because I heard it clicking when I tried to jump the car.  I tried to start the engine but there wasn't enough juice but the horn relay was clicking.
When I put in the new fully charged battery the horn relay would click once every time I touched the ground cable to the negative post.  I decided to change that relay since I had one and it doesn't click anymore when I touch the ground cable to the negative post.
When you test the alternator are all four wires are to be removed is that correct, or is it just the heavier battery and ground wires that are to be removed?

[jbcollier]

There are some capacitors in the system that briefly charge when the battery is hooked up.  That is why it will read "x" and then slowly go to zero.

If the horn relay "clicks" it will draw the battery down.  Did/does your horn work?

Can you send a picture of your ammeter?

[rjbaren]

The horn did work with the old relay and continues to work with the replacement relay.

[jbcollier]

Hmm, not too wild about that meter.  First, let's test it.  Put the test light across the battery with the ammeter in the circuit on the 10 amp scale and using the 10 amp connections.  Does the lamp light?  What does the meter read?  Now try it at the 200ma setting and hook up.  Does the lamp light?  And, what does it read?

[rjbaren]

I may have burned out the meter.  I connected the test light which lit brightly.  I connected the meter at the 10 amp scale and it sparked and got hot and smelled instantly.  When I disconnected the meter it took a while for the numbers to go to zero.  I connected the wires to the meter in the 200ma setting and the numbers went down to zero and then went to negative 45 and was still going.  So I turned it off. 
After 10-15 minutes being off with no leads connected to the meter, on the 200ma scale it is reading -36.8 and descending.  Now -68.1 and still going.  It also rattles now too. 
The rattle was a spare fuse.  But it is now reading 139.3 and still going.

[jbcollier]

You had the test light in series with the meter?

[rjbaren]

I had it connected at the same time.

[jbcollier]

It has to be in series:

battery positive post -- first test light lead -- test light -- second test light lead -- ammeter lead -- ammeter -- ammeter lead -- battery negative post