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Slow voltage drain. Any suggestions?

MerlinsMopars

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My 71 R/T 340 4 speed has been up and running since November last year and has been sitting for a few months over the winter. I went to start it the other day and the battery was dead. It was a new 1045 amp Napa one. I threw a little charge in it and it fired up.
I have a Mopar 110 amp 1 wire alternator in there with 8 gauge direct to the battery and extra ground wire to the body as suggested. Running MSD 6al 2 and it's triggered by the brown and blue wires together as required for start/ run. No issues with that as far as I know but when the battery is connected, I notice a slow voltage drop. if disconnected, no drop. No lights on, glove box etc. no stereo yet either but I do have the tach adapter.
Any ideas would be appreciated. I really don't want to put a kill switch in but leaning towards it.
Thanks!

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MerlinsMopars

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Forgot to add that I also hooked up the original wire from the firewall along with the 8 gauge going to the battery. Thx
 

Challenger RTA

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If it's going to sit for awhile. Charge the battery back up. pull all the fuses. That will narrow it down where it might be. A test light across each fuse connection. Also a quick check. Remove alt charging wire place a test light between the wire and stud. If it lights the alt has a short. Even a faint glow in the dark.
Remember if the battery is hooked up when removing alt wire it is always HOT!
 

Challenger RTA

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A few things that might draw power when it is off. Clock, bad ign sw not turning off, bulkhead connectors corroded and shorting to ground, park sw you don't have. And a broken wire insulation bleeding off to ground. Headlight sw dimmer sw. There are others look to see what you find.
 

sixpactogo

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An electric clock will drain a battery over a few months time. The best way to find the drain is to disconnect the Positive post from the battery. Hook a digital amp meter (in mili-amp scale) between the cable and battery post. If you have a drain, it will show up. Then start pulling fuses until the drain goes away. That will show you which circuit is the culprit. If you still have a drain with all the fuses out, your drain is likely under the hood or a partial ground somewhere. Alternator could have a bad diode but that would normally drain the battery overnite. Diligence is your friend here. I have a factory clock in my 65 Fury that will drain the battery over time. I put a battery post disconnect in all of my collector cars for that very reason. One of these......

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TripleBlk70

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Instead of a kill switch could you do a battery tender? In my "other" muscle car I have a clock as well as a radio and a gps tracker I want to keep fully charged in case the car is ever stolen...and it can go weeks without being started so I use a battery tender to make sure my battery never ends up dead.
 

MerlinsMopars

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It does have the rally dash with clock but it's not working currently. It could be the culprit. I am going to test like sixpack mentioned and hopefully find something. It was a brand new 1045 amp battery so I was kinda shocked to see it was completely dead in three months. My charger srt has security and clock in the radio and sat longer but fired right off
I appreciate all the input from everyone.
I completely assembled the car in a lil over 6 months and it was a lot to do after work and weekends. I burned myself out doing it and once it was running, I thought it was over with. Lol
I got a break from it but the bugs got to get worked out now.
I want to start assembling my Demon this spring but I am not starting that till this one is perfected .
I will post what I find soon.
 
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