battery drain

[sflaten]

Hoping someone on this forum ran across this problem in the past and can tell me if this is a common FM condition and help me narrow the hunt for the cause.

Was racing yesterday and having issues with internal electrical power. Battery was new May of this year and this is the second race since then. hard time starting car as it drained the battery trying to get it started on a minor flood condition. Put a charger on for a few hours and it seemed to pop right off once I dried out the plugs. Went to start it for the main race and had nothing. Got a couple guys to push start me and ran the race. Got to the last two laps and the lights on the PI dash started flashing and I saw a battery warning of 5 volts on the PI. Car started to faulter and it died going into a corner but popped the clutch and restarted, so i pulled into the pits. it idled a bit low and coughed a couple times. finally dying as I was pulling into my pit space. Tried to restart and not so much as a click from the starter.

Pulled the battery and did a check and found it had 12 volts. used a guys tester and under load it said it needed to be charged and very low on the CCA. Took it back to Napa and they said it needed to go through their charge cycle to verify if it is bad. will need to do that tomorrow. Previous battery went out in similar quick drain which I thought was just age. One final thing is O had a little mishap at the grid on a qualifying race. Went to flip on the ignition and fuel pump switches. Ignition came apart in pieces in my hand. Wondering if that grounded if something could have been damaged, like the MSD or alternator, thus my plea to the collective FM community. Thought there may also have been a piece of wiring harness that has chaffed and will need to inspect it all. Did a continuity check between the battery leads with main power on and off and all seems to be OK.

Needless to say, it was one of "those" weekends.

More info. Had battery tested today after full charge overnight they say it is 100%+. I put it in car and started right up. let it sit for a few hours and still started with no iissues. Leaving it connected for a couple days and will recheck.
Steve F

[wannabe]

1. check the main on/off switch. I just replaced mine after having same problem.
2. alternator wire to main maybe grounding if unprotected.
3. bad alternator with intermittent charging/battery drain.

Those are my top three...good luck

[sflaten]

Thanks. Have let car sit for three days with main power switch off. Car started right off. Plan on digging into alternator and pulling off bodywork to look for any chaffed wire. Next step is to pull alternator and have it tested.

[dmccallum]

Turn everything off including the main power switch. Remove the positive battery cable from the battery. Hook a test light or a voltmeter between the battery cable and the positive terminal. Turn on the main power. If the light comes on or the voltage meter shows voltage, something is pulling power. The first thing to do would be to turn power off and remove the red power wire from the alternator. Then when you turn the power back on if there is no power drain, the problem is the alternator. If it is still pulling power, you will need to look for something else that is shorted. Hope this helps.

[formulasuper]

Dale is correct. If removing the alt wire doesn't cure it keep disconnecting power wires until you locate the source.

[sflaten]

Thanks guys. Hope to be able to dig in over the weekend. Hope that will find the glitch.

[sflaten]

Found the problem. Alternator appears to be bad when they tested it at NAPA