Author Topic: Battery drain after new engine install (Read 299 times)

68EFIvert · « **on:** March, 10, 2010, 09:37:31 PM »

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!!!!

Midlife · « **Reply #1 on:** March, 11, 2010, 02:41:46 AM »

http://www.stangfix.com/testforum/index.php/topic,5661.msg67585.html#msg67585

68EFIvert · « **Reply #2 on:** March, 11, 2010, 06:44:25 AM »

Thanks Midlife!

Sluggo · « **Reply #3 on:** March, 13, 2010, 05:06:22 PM »

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.

68EFIvert · « **Reply #4 on:** March, 13, 2010, 07:48:21 PM »

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.

AzPete · « **Reply #5 on:** March, 13, 2010, 07:53:49 PM »

:amaz nice :coo

garner67 · « **Reply #6 on:** March, 13, 2010, 09:18:44 PM »

Quote from: 68EFIvert on March, 13, 2010, 07:48:21 PM

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.