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Discussion Starter · #1 ·
I'm having issues right my battery/alternator. If I let my's truck set for more than three days I have to charge the battery. The battery was brand-new five months ago, could it be an alternator issue. When the truck is running and I roll my window all the way up the lights dim.


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Toxic Masculinity
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Sounds like you have a draw on the electrical system pulling down the battery. When the truck is on the road it seems the alternator is doing it's job charging the system. When it sits a few days something is pulling the battery down. Unhook the batteries ground and lightly touch the ground cable to the negative post. If you get a strong arc you have a heavy draw. These can be a real bitch chasing it down.
 

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The traditional way to track down a draw/drain is to disconnect the negative battery cable and put a test light in series (if there is a draw, it will light). Then, pull fuses until the light goes out...now you've found the offending circuit. In many modern vehicles, though, certain control modules will draw a fair amount of current for a time after the battery is connected. You might try hooking up the test light in series, then waiting 30 min or so before you start pulling fuses.
 
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