Pinpointing a battery draw?

Snal~

Snal~

I Run A Tight Shipwreck (Tragic Boating Accident)
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Any thoughts on how to determine where a battery draw is coming from?
1993 Grand Cherokee, had an auxiliary battery in it with a selector switch when I bought it...now I know why.
Drains the (older) main battery in about a month of just sitting. Not an issue if I drive it once a week or so, but I need to figure
out the issue.
 
Test light and pull fuses one by one. When you find the fuse, then you have to trace that circuit. Usually start by checking switches, bulbs and wires that are exposed.

Patience.... no easy fix in most cases.
 
Had a 95 grand that would do the same thing. Best I could figure it was the factory alarm with doors locked or not, you will notice a blinking light on the dash with it as well I belieave. You might see if you could pull the fuse for it and see if it still does it. There was a hood switch for it as well on my 95 so if hood was opened it would set off alarm and seems like it cause a issue with it as well.
 
Jp8819;n30117 said:
Had a 95 grand that would do the same thing. Best I could figure it was the factory alarm with doors locked or not, you will notice a blinking light on the dash with it as well I belieave. You might see if you could pull the fuse for it and see if it still does it. There was a hood switch for it as well on my 95 so if hood was opened it would set off alarm and seems like it cause a issue with it as well.
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Hmmm...this one has 2 alarm systems, factory and aftermarket. I'll have to see where the aftermarket one gets it's power.
 
Snal~;n30155 said:
Hmmm...this one has 2 alarm systems, factory and aftermarket. I'll have to see where the aftermarket one gets it's power.
Click to expand...

I quit counting how many aftermarket alarms I have thrown in the trash due to various failures.
 
Snal~;n30155 said:
Hmmm...this one has 2 alarm systems, factory and aftermarket. I'll have to see where the aftermarket one gets it's power.
Click to expand...

Like I said mine was all factory and would do jt after about a week to two weeks of not driving it especially after battery got some age. Use to tick me off just never got around to trouble shooting since it never sat much till right before I sold it and always thought it was factory alarm pulling it down just becareful as the factory alarms would inhibit it from running as well. It allows it to crank and then cuts off before you could get it in gear if activated reason i suggest trying pulling a fuse before cutting wires.
 
check the lights in the trunk and glove box and vanity mirror.. I had an experience many years ago when a vanity mirror light was on all the time...until it melted the bulb housing enough to open the contacts....until it cooled and closed the contacts (light on/parasitic draw)...till it started melting again....etc
 
Disconnect negative battery terminal, install test lamp or DVOM set to mA in series. DVOM is right way to do it. Anything over 80 mA is a parasitic battery draw. 50 mA is better but 80 is acceptable. You can do it with a test lamp, but you have no way of telling how many mA the draw is. It takes VERY little power to light a test lamp. FYI. Pay close attention to brightness of test lamp if using that method.
 
Mike Overlay;n30162 said:
I quit counting how many aftermarket alarms I have thrown in the trash due to various failures.
Click to expand...

I cringe when I see them on customer's cars. Either they don't work right, they are causing some issue or a combination of both.
 
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