vince Posted April 18, 2017 Share Posted April 18, 2017 This is kind of an embarrassing question because I'm a electrical technician by trade, but I need some help. I've been trying to find the source that is draining my battery. If the car sits for a couple of weeks the battery is drained (unless i disconnect it) The battery has been tested and its good, it will hold a 13.6 volt charge while disconnected. I have placed a DC amp meter on each wire coming out of the original fuse block, finding no amp draw. I went so far as to pull one fuse a day and checking the battery voltage each day. Is there some trick or tips you can share? Quote Link to comment Share on other sites More sharing options...
Rob Peters Posted April 18, 2017 Share Posted April 18, 2017 Pulling the fuses one or two at a time was going to be my suggestion. You say you did that for a day for each fuse. You may want to give each one a little more than one day. To divide and conquer try this..... Pull half of the fuses and let it set for a week and then check the battery. If it does not drain reinsert those fuses and pull the other half and do the same. If either time you get a drain pull half of that group and do the same. You did not say if you have a trunk light and under hood light. If you do remove the light bulbs. Sometimes those mercury switches don't shut the light off and that could cause a drain. rob Quote Link to comment Share on other sites More sharing options...
vince Posted April 18, 2017 Author Share Posted April 18, 2017 Good advice Rob I'll give it a little more time and see what happens.. As for the trunk light I put mechanical toggle switch to turn it on when needed, the hood light was removed. Is it possible the light for the glove box or may be the cigarette lighter? Quote Link to comment Share on other sites More sharing options...
cny first gen 71 Posted April 18, 2017 Share Posted April 18, 2017 What kind of accessories have you added, radio or sound system? Additional accessories could be causing a large draw. Maybe a kill switch for now untill you find the problems. Quote Link to comment Share on other sites More sharing options...
monte70car Posted April 19, 2017 Share Posted April 19, 2017 I agree with Steve with the accessories. I know my with drain the battery with the aftermarket radio and gauges as it always pulls power for the memory. If you have an aftermarket dash clock it will drain the battery as it's always running. Quote Link to comment Share on other sites More sharing options...
black07ss Posted April 19, 2017 Share Posted April 19, 2017 Vince with the car off disconnect the negative battery cable. Take a test light and go from the battery lead and the other side of the test light to the battery. This will set up a series circuit with the test light. The light will glow according to the draw. Pull one fuse at a time. Pull and return fuse if the light remains the same. The light will go out once you pull out what fuse/circuit is keeping the light on. Quote Link to comment Share on other sites More sharing options...
stangeba Posted April 19, 2017 Share Posted April 19, 2017 Bob, good write up! I remember years ago using a "key warning buzzer" in place of the test light so you could hear when it went out. 1 Quote Link to comment Share on other sites More sharing options...
black07ss Posted April 20, 2017 Share Posted April 20, 2017 Also doing it this way the light will be very dim if you have an aftermarket radio and have the memory wire hooked up to a direct power source. You need to make sure the main power wire is wired to a power source that has power when the ignition is on. I assume you have not added anything new when the problem started. IMO it could also be your battery is just getting old and not holding a charge as well anymore. 1 Quote Link to comment Share on other sites More sharing options...
Mo's70MCs Posted April 20, 2017 Share Posted April 20, 2017 I'm with Bob, old crappy battery or bad diode in alternator. Quote Link to comment Share on other sites More sharing options...
vince Posted April 23, 2017 Author Share Posted April 23, 2017 Thanks for the replies my after marked radio and amp along with my gauges on the a pillar are all on a sepperate fuse block. That block has been disconnected in all my test. It is something to do with the original electrical system The batrery has been tested and it will hold a 13.6 volt charge all week disconnected. the alternator is brand new i replaced it with the 5.3l conversion. Bob ill do the test light test this week and see what happens. Steve i like the idea of a kill switch thanks Quote Link to comment Share on other sites More sharing options...
o_rod Posted April 23, 2017 Share Posted April 23, 2017 I'm with Bob, old crappy battery or bad diode in alternator. When my diodes went it did constantly drain my battery, all it takes is a small short circuit or reversing polarity on the battery to toast them. I don't know the details on your swap but my "gen" dash light was on all the time, even when the ignition was off when my alt went bad indicating a constant draw. Quote Link to comment Share on other sites More sharing options...
Mo's70MCs Posted April 23, 2017 Share Posted April 23, 2017 When my diodes went it did constantly drain my battery, all it takes is a small short circuit or reversing polarity on the battery to toast them. I don't know the details on your swap but my "gen" dash light was on all the time, even when the ignition was off when my alt went bad indicating a constant draw. Funny! How we all in need manage to find a better solution. For me the 10si one wire did the trick, I basically left the existing wiring intact left the old regulator in place, and just used the main battery wire to the alternator. The self exciting 63a was the ticket for me. There's only been once where I had to manually excite it and that's when I took the unit apart to replace brushes. 1 Quote Link to comment Share on other sites More sharing options...
vince Posted April 24, 2017 Author Share Posted April 24, 2017 that's a good point I'll disconnect the alternator as part of my test. It may take a week or two but I'll find the problem. Quote Link to comment Share on other sites More sharing options...
vince Posted April 30, 2017 Author Share Posted April 30, 2017 OK so the root cause's has been identified. I installed aftermarket gauges on the A pillar ( tech and temp) they require a constant hot and a acc hot, I had them landed backwards on the fuse block. I was also getting some draw from the cig lighter so i disconnected it, and I found that the battery is dropping voltage at a very low rate. I'll get a new battery this week and hopefully my draining issues will be gone. 3 Quote Link to comment Share on other sites More sharing options...
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