Having trouble with a battery drain...

[95AWD6Bolt]

So, I have a battery drain so that my battery dies every two or so days. I have followed the tech article for finding an unknown cause of a batter drain. I went and bought a test light and have narrowed it down to being somewhere in the "room lamp" fuse in the fuse box in the engine compartment.

From there, I have tried checking and turning on and off fuses, radio, random plugs, etc. and have still not located it. I have a 98 gsx and do not have a "room lamp" in the middle of the headliner behind the sunroof. I am assuming that this is what a room lamp is.

Does anyone know what exactly is powered by the room lamp fuse in the engine compartment so that I can find this drain.

thanks

 

[TOONAH]

Sounds like you need a bit of help.
Fuses do not short partially to ground and that is what you are trying to find. A partial electrical short to ground.
In order to trace an excessive current drain on an automobile battery installed in the car,
you really need a current clamp meter or a multimeter that can measure at least three amps.
First of all, the ECM (brain box, aka computer) is always on and it draws about 200 mA per hour. With all other electrical devices off, that 200 mA is all you should measure.
If it is more, the first place I look is for a shorted diode in the rectifier/regulator module (inside the Alternator). It acts like a
partial short and causes a 6-10 Amp per hour drain.
That is my advice to you. Take out the Alternator (its an easy job) and run it over to Autozone, where they will test it for free. I have actually troubleshot your symptoms down to a bad alternator twice in my life, so you can believe me. It is not something I made up. And yes I do have a degree in electronics!
A little theory for you. The Alternator is a six phase AC generator. Consequently, the AC voltage must be rectified to DC and then regulated to 13.6 VDC. Regulated means that the output voltage remains constant from no load condition to full load condition. Any rectification process does not create perfectly flat DC voltage. There is always a percent of ripple (AC voltage) riding on the DC. Six phase AC rectification produces very little ripple. Car batteries (indeed all wet cell batteries) do not like AC ripple. It will, if excessive,
damage the anode and cathode plates inside the battery.
So if you had an oscilloscope, you could run the engine and put the scope on the big red wire from the alternator at the battery plus terminal and measure the AC ripple. If it exceeds 30 mV at rated load, then the culprit is a shorted diode.
Hope you find the partial short. Please reply and let us know when you do find it.

 

[my dreamt dsm]

My friend had something similar but I can't really remember what he did! Sorry... Good Luck though.

 

[95AWD6Bolt]

Ill take the alternator out next time I get a chance to work on the car. Can autozone or anyone check the alternator while it is still in the car?

I looked at it tonight and I could only see one wire connected to it.

 

[Hardin]

Might wanna check fuses too.

-Hardin