Battery Drainage. I can't track it down. Need some help Big time..

Hey guys. Like the title says I got a battery drainage issue in my 63 Chevy pickup. I am not good with the electrical aspects of a automobile.

I just bought this truck and the previous owner did me the favor of having it nice and charged up when I came to look at it and failed to inform me of this issue.

I have read through some of the old post on here and tried to use the info I found to track down the little monster but have had no luck. I'm left scratching my head and very confused I don't know what to do..

First of all the battery in the truck is good and fully charged. I had it tested twice at two different parts stores.

The alternator is brand new and was installed by the previous owner.

Starter is also brand new and installed by previous owner.

(have receipts for these items) They look new too.

The engine and trans are from a 85 Chevy 1/2 ton. The alternator and starter are for that application.

There is no radio or electric fans. There isnt any power accessories at all that I can think of.

The truck starts like a champ and battery stays charged as long as I Unhook the positive battery cable when I am done driving it.

I read on here about doing a test to see If I have a battery draw by removing the negitive battery cable and connectiong a test light between the negative cable and negative battery post. If the test light shines you have a draw. Well this is what I did and the test light shines bright.

I tried disconnecting the external regulator. ( I dont think this truck should have one with the newer alternator setup ) Test light stayed on.

Then I tried disconnecting the main harness from the firewall. I dont know if this was useful but did it anyway. Test light stayed on.

I then disconnected the brake light switch. Test light stayed on.

I then decided to pull the fuses one by one putting them back as I go. Test light stayed on..

I figured maybe I'm doing this wrong so I start over with the fuses this time pulling them ALL out. Even with all of them pulled out The freakin test light stayed on!

CRAP!

I then tried unplugging every harness I could see with no luck as well.

I took some pictures so you all can see how the alternator is wired and how one wire goes over to what I think is the horn relay which is near a regulator.. I don't think its stock because it has a 4 terminal plug not three. If im not mistakin the stock one for 63 is suppossed to have 3.

I considered starting over fresh with a new Rebel harness but the shops around here want big money to install it for me. quotes were ranging $800 - $1,300. Long story short I can't do it were I'm at because I live in a apartment. so I have to farm it out..


Anyway I need help big time...Heres some pics..






Here you can see where the wire above from positive terminal is connected.

 

You're methods for checking for a parasitic load is right as you have explained it. I would keep my focus there, its obviously the issue. Somewhere you are missing something. Just take a deep breath and go back at it.

 

I had an electrical drain problem and couldn't figure it out. I'm like real dumb when it comes to mechanical and/or electrical applications. This was a couple of years ago. Somebody suggested that the alternator was the culprit. It was new so I didn't think it could be it, but it was. Do a search on how to test it if you haven't already. Got another one and replaced it, and haven't had a problem since.

 

Here's a diagram for a 64 car, pretty much the same layout as a pickup. Think about what works without a key. Dome light, brake lights, horn, cig lighter,..... of course pulling fuses would open them up, well you'd think............

I had a Chevelle and the glove box light stayed on all the time. Drove me nuts finding that. Kinda like is the light still on in the fridge.

http://www.tocmp.com/tOCMP/wiring/5765wiring diagrams/Chevrolet/MWireChev64_3WD-075.jpg

 

From the pics Im going to guess that the unhooked wire at the alt is part of the problem.when you unhooked the large connector at the firewall you unhooked everything inside the cab including the fuse box. your problem is under the hood and that looks like an internal reg style alt with th external one still hooked up,try unplugging the alt and see if your test light goes out. I think the unhooked wire should go to a switched power source.

 

That unhooked wire needs to go to the ignition switch. You can put a diode in this wire, or you can put a 12 volt lamp in the dash for an idiot light. Wire IGN or ACC +12V to one side of the light, and the alternator to the other side of the light.

This wire supplies +12 volts (called the exciter terminal) to the alternator. Without it, you are not charging the battery.

EDIT: Just another thought. The test light may light with even a very small milli-amp draw. Obviously something small can turn on the light. Maybe unscrew the wire from the horn relay, and that should tell you whether it is after the relay.

EDIT2: Pull the regulator out of the circuit. It isn't needed anymore. Put it in the dumpster

 

I forgot to mention I unplugged this harness also and the test light stayed on. If that makes a difference. I did not undo the bolt and pull the red wire on the back of the alternator that goes to the battery though, that slipped my mind to try that..

Also what about the external regulator. Thats not suppossed to be there right? since the alternator is for a 85 chevy pickup.

 

Yes, try disconnecting the alternator BAT wire. The light should go out. What is happening is, the current is flowing from ground, through the alternator diodes, and to the positive battery terminal.

This is a small current that normally doesn't discharge a battery overnight. If you plan on leaving the truck for a week or more, disconnect the battery as you vacation wherever.

I think your real problem is the battery isn't getting charged, and that's what the exciter wire is for.

 

This kind of stuff will drive you nuts! It sounds like you've pretty well eliminated anything that's on a fused circuit. I'd leave the fuses pulled and start looking over any wiring between the battery and fuse panel and look for any sign of splices or added wiring that's not routed thru the fuse panel or an inline fuseholder. You may have to unbundle some harnesses and retape them when you're done. Any indication of aftermarket stereo, lighting or trailer wiring installations? Are the headlamps on a fused circuit? I thought that sometimes headlamps weren't fused but instead had a circuit breaker in the switch or in the circuit. The thought was that if a short or overload occured, rather than blowing the fuse and leaving you in the dark, the breaker would cycle off and on and give you flickering headlights till you could safely get off the road. See if the switch feels warm or just unplug the wiring from it and see if the test light goes out.

Maybe a stereo was installed with some "sub-standard" wiring and would occasionally blow the 3amp inline fuse. Maybe someone put a 20amp fuse in its place to "fix" the problem? Has someone added an underhood lamp or glovebox lamp? Sometimes they don't shut off when they're supposed to but you can't see them still burning. Of course they should fused but who knows how a previous owner may have wired things up.

Good luck! You'll feel like Thomas Freakin' Edison when you get it figured out!

 

The wiring on the back of the alt is correct. It is done to convert to a one wire style.. It will work fine this way, except sometimes you have to rev the motor when just started to get the alternator to kick in..

I agree with above, disconnect the fat 10 guage on the alternator stud, and check draw.. The internal regulator can fail and draw power back through the 10 guage wire.

 

Don't know if someone mention this or not or even it's possible in your case. We had a van several years ago, and when through 3 or4 batteries in a year. Dealer when over the entire car and could not find anything wrong with it during the first three years. They just scratche their heads and put a new battery in every couple of months. If the car sat idle for a week or two, battery would be dead. After several repeated rechargings, the battery wouldn't hold a charge and had to be replaced. Dealer and Chyrsler got real sick of replacing batteries.

They finally stumbled on the problem which was a tiny short in the ignition system that when the car was not run for a week or so, would deaden the battery. Once the problem was corrected we got never replaced another nor had any more drainage problems.

So if you can check out your ignition system. Wiring and all components.

Hope this helps.

 

the '63 should have a warning light, find the #4 wire on the regulator, cut it and hook it to the white wire on the alt....then toss the regulator. also go buy a cheap multi meter, set it on 10amp scale, hook it between battery and cable, a .050 amp (or under) draw is ok. my '64:

 

You may be able to narrow the circuit down by removing one fuse at a time and waiting to see if the battery still drains. If it drains, put that fuse back in an pull another one.

 

Thats where I would start - alt wiring

 

If disconnecting the batt wire to the alternator doesn't cure it, check tosee that you don't have a voltage loss across the top of the battery. I have seen that several times where the battery drained across the dirt and moisture on top of the batteary.

 

If you do find that the drain is across the top of the battery, I would clean the battery with baking soda and water, then wipe the battery down with ATF. ATF doesn't conduct electricity and makes it easier to clean next time.

 

Guys I just got in from pulling the wires off the back of the alternator. I did one at a time and tried it with all of them off also. THE LIGHT STAYED ON.. god I hate electrical

 

If there was a draw across the top of the battery wouldnt the test light still come on when connected to the negative post and negative terminal if the positive was unhooked? If I unhook the positive cable doing the test light thing the test light wont come on.

 

You can check voltage at the battery with a voltmeter when running to see if the alt is charging. Should have 13.5 to14.5 volts. The best way is to have a tester (like a Sun VAT 40) that can check how much voltage and amperage the alt. is putting out while the truck is running. The same machine can put a load on the system at the same time, ck starter amp draw, and ck if the diodes in the alt are bad.
Bad diodes in the alt. will drain the battery. I think everybody is on the right track on the alt not charging issue. Go get yourself a battery hydrometer so you can check the state of the battery charge yourself ,assuming you are not using a sealed battery, that is.
You can learn much about all this stuff on MAD Electrical's sight if it is still up.

 

Would this still be a possible solution if the test light is still on after removing the alternator wires?

 

is the original voltage regulator still on the truck ? could he have possibly hooked it back up to the new alternator ?
if he did, the voltage regulator may be backfeeding the voltage to the alt. and not letting it charge the battery.
the alt. that's on it should have an internal voltage regulator.

 

im confused on what the alternator charging has to do with the battery having a draw on it.

I think It's charging cause it will stay charged as long as I dont leave the positive cable hooked up when I'm not driving it.

It will fully discharge overnight if the positive cable is left on..

Could somebody explain this to me.

 

What is the regulator hooked-up to? Anything?

At any rate, remove it, your alternator doesn't need it.

 

It's a question of use of technology. A test lamp is good for checking continuity, but it sucks for just about everything else.

Stop by radio shack and get a $5 multi-meter. These things measure voltage, and current.

Tell us how many amps or milliamps the circuit draws in the place you're putting the test lamp.

Tell us how many volts you read with the car off, and with the car running at 1200 RPM.

Define "draw" for us. How much current is the light drawing?

 

dose that alternator have the stock voltage reg. in it? if it is, it won't charge like that. use a volt meter and check it running (around 14 volts). if it is around 14 volts dissconnect the coil wire and crank it for about 10 sec. check the voltage again, if it's over 12.8 volts the battery is bad.
also the test light needs to be one with a bulb and not an LED.

 

K guys I found a multi-meter

i wired the meter the same way I had the test light wired and the only way the meter would give a reading was on AC-v 15 on that it read 9.5 - 10.0

On the other settings it wouldn't even move or would go backwards..

this tell us anything?

 

If you put the meter in series with the battery cable, then you need to set it for amps. Sometimes you have to move the meter probe wire to a different plug on the meter for amps.

The only other setting to use will be DC volts, and for that just put the probes on the battery terminals: meter + to battery + (pos) and meter - to battery - (gnd).

 

Sounds like your testing procedure is correct at his point I would and not sure if you mentioned it or not totally unplug the alternator and see if the light stays on. If it does then you have no choice but to systematically disconnect every thing under the hood. You have eliminated everything inside the cab when you disconnect the main harness and suspect you eliminated the rear of the truck by doing this as well. Being as this guy swapped engines and he's leaving in the old regulator hoked up but is using the new alt. and it is hooked up also. I have a sneaky suspicion that he either spliced the new and the old harness together or physically check every wire where it may come in contact with the frame or any sharp sheet metal etc. You most definitely have a direct short. I chased a short like this on a late model car for almost a week and couldn't find it. I was bleary eyed one night and for some reason the fact that the paint on the inner fender didn't match the paint on the outer fender got me thinking. So before I went and tore the nose of this piece of junk off I called little miss Blondie who owned the car and asked if she had gotten in an accident recently. "What does that have to do with anything" typical answer so she confessed and after removing the right front fender we found where the geniuses at the body shop had the harness rubbing up against the ragged sheet metal from the crash. Being as you have gotten just about all the good advice anyone could give and you've foll wed it I suspect you have a similar problem.

 

This means that something is drawing 9.5-10 AMPs all the time when the truck is off. I would recomend taking out all the fuses and use the ampmeter to see which circuit has the draw, just to eliminate anything there. put the test conctions into where the fuse goes to complete the circuit. If you find any circuit that has a draw more than 1 AMP when the key is off then you know that is the circuit with the problem. If you can live without that cicuit leave the fuse out. If you need it then you need to trace the wires and see what is wrong.

 

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Do this, if you have a volt meter put one lead on the proper terminal of the battery and touch various areas of the top of the battery with the other to see if you show voltage. I've seen as much as 9 volts go across the top of a dirty and damp battery top. One of my students fought that with his mid 60's Chev pickup when I was teaching. If he disconnected the battery terminal it didn't discharge but if he left them connected the battery drained in about 3 hours. If you get a voltage reading across the top of the battery wash it off good and see what happens.

Since you have an internal regulator you don't have to worry about the external reg but you could still have a bad diode even in a fresh alternator.