tracking down an electrical drain



tracking down an electrical drain

Postby grumpyvette » January 24th, 2013, 2:52 pm

one of the more common problems I see in older muscle cars and corvettes is that, many of the guys that own those cars, have the cars used rather intermittently or only on weekends, not as daily transportation, and as a result when they do go to use the car the battery's dead.
this is almost always a case where your forced to track down the source of the electrical drain issue by isolating the individual circuits by pulling fuses and testing each individual circuit,with a multi-meter. and Id sure pull trouble codes and get out the correct shop manual as they can be very useful in tracking down an electrical drain.
if you use a trickle charger verify its functioning with the multi meter before you start, both the battery and the trickle charger can be defective and just because the trickle charger has an LED light that works is no indication it actually works correctly, and battery's do wear out or become defective, so don,t jump to the conclusion your cars got a problem until you verify everything , battery don,t fully recover from repeated full discharged condition, so yes you need a trickle charger on a seldom used car.
leaving your interior lights or head lights on will kill the battery in as little as a few hours, thats not a fault in anything but the guy operating the car, but if you find the car battery dead and you didn,t cause the problem by neglecting the cause, you can track it down and isolate the offending electrical drain.
now if you don,t use a battery minder or charger its totally understandable, if you leave the car for several weeks between brief trips, that the battery will go dead, simply because the car never gets the battery fully charged. this is a fairly common complaint, obviously you'll want to locate the battery drain source,if this happens frequently or in only a few days time. and thats best done with the correct meter and pulling fuses until you locate the defective circuit, thats causing the electrical drain.
obviously you want to verify the battery takes a full charge and the alternator functions correctly and your battery connections and electrical grounds are good during the process.
a logical step by step approach will lead you to the problem, youll be amazed at what youll learn reading links. use of a shop manual and multi meter can be very helpful
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[b]But heres a few tips.

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[size=150]having an amp draw meter can be quite useful at times, knowing how to use it obviously helps also,
SO READ THE INSTRUCTIONS THAT COME WITH IT AND FOLLOW THEM

the amp draw meter can be used to measure the current flow and as you disconnect fuses you can isolate the source of the current drain

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http://www.harborfreight.com/5-in-1-dig ... 98674.html
]having a wide assortment of different multi meter test leads available is a huge benefit while testing
the clip test leads that test thru a wires insulation without much damage are a big help

SENSOR LOCATION INFO
viewtopic.php?f=80&t=728&p=1025&hilit=camaro+sensors#p1025
Sensor Locations
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http://www.madelectrical.com/electrical ... ging.shtml

http://www.corvettefever.com/techarticl ... placement/

viewtopic.php?f=32&t=2697&p=29270&hilit=code+corvette#p29270

http://www.hotrod.com/techarticles/gene ... ewall.html

http://tech.corvettecentral.com/2007/08 ... diagnosis/

if your car sits for days at a time you need a trickle charger
http://www.harborfreight.com/automatic- ... ader-42292

I bought 4 for $5 each when they were on sale a few years ago, two still work fine and two crapped out , and stopped working in that time.
still at the price no real complaints

(1)If the cars fairly modern and you have the option pull trouble codes.

(2) if you don,t have a shop manual GET ONE, your working at a disadvantage without one!

(3) youll need a multi meter and it sure helps if you fabricate a 12 volt buzzer with about 8 ft long leads and alligator clip ends

(4) obviously youll want to know where the cars fuse block is located (SHOP MANUAL HELPS)
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Youll generally want to start by disconnect the neg battery cable and connect the 8 foot long test leads you fabricated on the 12 volt DCV voltage buzzer with the alligator clips between the battery and the disconnected cable, the buzzer well start buzzing, thats normal, now go to the fuze panel and remove one fuze at a time and listen to the buzzer (the reason it has 8 foot long leads is that you can keep in near you), when you remove a fuse that controls a circuit where current flows you will notice either a slight reduction in buzzer volume or the buzzer will stop,buzzing until the fuze is replaced.
Id also strongly suggest you don,t touch the ignition key for two reasons, first if you try to start the car with the battery cable disconnected and the buzzer in place the buzzer will almost instantly burn up, a good quality 12 volt 10-20 amp DC buzzer to test with is usually very useful and secondly, your battery drain occurs while the ignitions off so turning it on changes the circuits that are energized and gives you bad info[/color]
Once the offending circuits located get out the shop manual and find and fix the problems source

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having a good set of needle nose pliers helps here!
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Most alternators fail when they can,t keep the battery charged , most defective battery's fail to maintain 12-13 volts or retain a charge, usually reading less than 12 volts or drop off very rapidly under load, If your getting over 15 volts at the battery Id suggest retesting, the first step would be to remove the fan belt temporarily for a short duration test, and start the engine with the MULTI meter to see what the battery is actually doing under load VS what the alternator is producing.
if the battery stays under 14 volts and only reads higher than 15 volt with the alternator connected its more than likely the alternators internal voltage regulator is defective, its also a good idea to have more than a single multi meter to confirm voltage or resistance readings, if they seem really odd.

http://www.harborfreight.com/5-in-1-dig ... 98674.html
heres a cheap yet effective multi meter
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Ive purchased several 200 amp alternators from the guys at
http://www.dbelectrical.com/casearch.as ... ageSize=60

http://www.dbelectrical.com/p-9594-alte ... -1993.aspx

http://www.dbelectrical.com/p-3478-ford ... t-101.aspx

https://www.youtube.com/watch?v=zdIKNnwEjIs

https://www.youtube.com/watch?v=VcRG-XBzk7U

and Ive also had several minor NON_RELATED electrical issues with alternators and electrical drains that they were very helpful in diagnosing, the main thing youll want to do is install a new direct connection, 4 gauge power lead from the new alternator to the batter positive terminal.
youll very likely find that your engine runs cooler and your fans run much more efficiently once they can get all the current they want, youll also find the ignition spark is much brighter if you get the same results Ive seen every time.
Youll also want to make very sure your electrical grounds are solid and think thru your ignition instal, most MSD control boxes fail due to heat or moisture, mounting them in a reasonably cool dry location helps and that ELIMINATES inside the engine compartment,mounting the controller in the upper most possible location in pass side foot well as far up under the dash as you can mount it is a frequently suggested and used location



RELATED THREADS, don,t forget too check for defective sensors and relays and grounds


viewtopic.php?f=80&t=728&p=1025&hilit=sensors+camaro#p1025

http://www.msdignition.com/page.aspx?id=3206

viewtopic.php?f=32&t=3954&p=18559&hilit=corvette+alternator+cable#p18559

viewtopic.php?f=70&t=6964&p=22890&hilit=corvette+alternator+cable#p22890

TESTING AN MSD IGNITION
viewtopic.php?f=70&t=1179

viewtopic.php?f=70&t=6961&p=22863&hilit=test+alternator#p22863

viewtopic.php?f=36&t=8493&p=29779&hilit=trouble+diode+ignition#p29779

viewtopic.php?f=70&t=855

viewtopic.php?f=70&t=2798

viewtopic.php?f=70&t=5425

viewtopic.php?f=70&t=3797

viewtopic.php?f=70&t=251

viewtopic.php?f=70&t=232

viewtopic.php?f=32&t=2697&p=37334&hilit=corvette+grounds#p37334

I make this info stuff easy to find


RELATED THREADS, and as always theres a ton of related info there that if you skip reading youll find it takes you longer to locate your problem


viewtopic.php?f=70&t=986&p=7010&hilit=buzzer#p7010

viewtopic.php?f=32&t=2697&p=29270&hilit=multi+meter#p29270

viewtopic.php?f=70&t=2133&p=19303&hilit=trickle#p19303

viewtopic.php?f=44&t=8155&p=28287&hilit=multi+meter#p28287

viewtopic.php?f=44&t=808&p=1180&hilit=fuse+block#p1180

viewtopic.php?f=70&t=5425&p=16181&hilit=ignition+diode#p16181

viewtopic.php?f=36&t=317&p=27440&hilit=shop+manual+purchase#p27440

viewtopic.php?f=36&t=3222&p=8575&hilit=testing+alternator#p8575

viewtopic.php?f=87&t=5492&p=16502&hilit=trouble+codes#p16502
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

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Re: tracking down an electrical drain

Postby grumpyvette » October 6th, 2013, 4:59 pm

Bobs car recently started draining the battery over night,he asked me to help isolate the problem. a few minutes testing by pulling fuses, to locate the defective circuit , while having a multi meter and amp draw meter,to check current flow soon isolated the problem to the interior light circuit, further inspection showed a defective door contact which was the cause but without the skills to think it thru and isolate the source and the tools (MULTI METER, and SHOP MANUAL showing the circuit and fuse numbers etc. ) that could have been a huge P.I.T.A. to locate! you don,t always need a AMP DRAW METER a GOOD QUALITY 12VOLT 10 AMP rated BUZZER will change tone noticeably if you connect it between the battery pos (+) and BATTERY POS(+) cable you temporarily disconnect for test purposes
in some cases BAD DIODES in an ignition ,or a voltage regulator or alternator can cause a voltage drain, that kills a battery over night or over only a couple days so be aware thats one potential source , that it might not be a shorted , or grounded wire issue
IF YOU CAN,T SMOKE THE TIRES AT WILL,FROM A 60 MPH ROLLING START YOUR ENGINE NEEDS MORE WORK!!"!
IF YOU CAN , YOU NEED BETTER TIRES AND YOUR SUSPENSION NEEDS MORE WORK!!
grumpyvette

User avatar
Site Admin
Site Admin
 
Posts: 14105
Joined: September 14th, 2008, 1:40 pm
Location: florida


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