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Battery drain after new engine install

68EFIvert

Well-Known Member
I got a weird problem that likely has a simple solution. I have been trying to get the little bugs worked out on my car and I keep having to charge the battery. I finally broke out the volt meter and noticed something interesting. The battery is in the trunk but I checked voltage from a distribution block in the engine. After charging the battery I can watch the volts drop about .01 every second or so. 11.96....11.95.....11.94 and so on. I disconnected the negative post on the battery and checked the battery. It held the charge.

I added a couple of accessories with the swap. I added an electric water pump that is run through a 30 amp relay. It turns on when the key is on and does not run when it is off.

I added an additional relay to operate two more fans (4 fan radiator setup). Non of the fans have turned on so far. Haven't got it hot enough yet.

I added a H2O/Methanol injection kit. It uses an electric pump that I did not wire through a relay. It is triggered on by boost. It has a ground wire that I attached to the same ground I used with the original electric fan setup.

Where do you start when checking for shorts. My underwear look clean so now I need to look at my car. :lol

I never had a problem before I put these accessories on. Thanks for the help!!!!
 
That sounds like an awful large draw you got there.

I would disconnect the battery and check it isolated from the car. Maybe the battery is kaput. If nothing else, just to eliminate it as a possibility.

Never seen one discharge quite that quickly.
 
I think I am need of a doofus nomination on this one. When I changed from a threaded rod to a stud for the alternator mount I forgot to connect the plug on the EFI harness to the alternator. It basically turns the alternator on when the engine starts. The alternator wasn't charging and I could see the voltage drop. I guess the dropping volts on my batter when not running must have been the meter trying to get an accurate measurement. Like I said, maybe a dufus of the year nomination.
 
"68EFIvert" said:
I think I am need of a doofus nomination on this one. When I changed from a threaded rod to a stud for the alternator mount I forgot to connect the plug on the EFI harness to the alternator. It basically turns the alternator on when the engine starts. The alternator wasn't charging and I could see the voltage drop. I guess the dropping volts on my batter when not running must have been the meter trying to get an accurate measurement. Like I said, maybe a dufus of the year nomination.

Sure, that's a less than brilliant maneuver, but I don't think it qualifies as a doofus move. I believe there needs to be some sort of injury inflicted to earn a doofus award. No blood drawn, no doofus.
 
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