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electrical nightmare!! HELP ME!!


thegnugod

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My alternator in my 76 buick has begun constantly discharging , 4 alternators later new an rebuilt this problem still persists I have taken the latest one an had it tested it is working perfectly out side the car an I cannot find any shorts in my electrical system help me please I have exhausted all my usual resources .

gary

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Have you checked your starter for shorts? Starters can short from within, creating a drain. A short in a starter can also be intermmittant which are always the most fun to find. crazy.gif

Have you load tested the battery?

Do you have an alarm system?

Any accessories that use constant on power?

If you have replaced your alt. 4 times, then it is safe to say it's probably not the alternator.

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This may sound stupid, but is your alternator belt tight enough? I had the same problem with a 1981 Monte Carlo I once owned. I did the alternator twice and could not keep the battery charged. Then I noticed the lights dim as I revved up the engine. I did the belt up tighter than normal, and never had another problem. smile.gif

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the smart move would be to take out one fuse a week....

disconnecting one system at a time......

aftet the week is up and the battery is good, then put that fuse back in an go to the next...

Note: the horn and the starter are the only two systems not fuses because of the large amp draw.

Now, you'll make some progress.. smirk.gif

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<div class="ubbcode-block"><div class="ubbcode-header">Quote:</div><div class="ubbcode-body">I have a complete Lucas electrical system from a '58 Jag </div></div>

So it must have intermittent wipers too? smirk.gif

Believe it or not, Amphicars have Lucas electrics too! A car that goes on the water with Lucas electrics! crazy.gif

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The first line of your message said "The alternator" is discharging???

Do you mean that the ammeter (probably not in a 76 GM car) or signal lamp is showing discharge when the engine is running? Or is the battery dead after the car sits 24 hours or longer unused??

If it is the latter, disconnect the glove box lamp and trunk lamp if equipped with them, clock also and then with everything electrical off, key out of ignition, disconnect the NEG battery cable at battery and connect an ammeter in series between the battery NEG post and loose cable end, if there is current flow indicated you do have a circuit to locate and isolate to cure the battery drain fault. Start by pulling fuses until you find the circuit that is puling current. There are circuits previously called attention by other replies like starter and horns that are connected thru "Fusible links", special cables that all get spliced together at the POS battery cable, they would be the next to isolate one at a time until the drain is discovered.

Then you have the possibilty of a previous owner connecting some accessory load to the wrong terminal of the ignition switch (Battery POS post) rather than ON or RUN post, alarm system or CB radio etc.

There really is no magic to electric, it starts flow from the battery to the load through a switch or fuse and returns through ground (Chassis metal frame).

Good luck. Stude8

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Guest imported_PackardV8

disconnect (or pull fuse) from clock and any other accesories that may draw current when ignition is off.

Disconnect one battery terminal. IN A DARK garage touch the disconnected terminal to the battery post AND WATCH CLOSELY for a spark. OR use a volt meter. If there is a spark or v-meter shows a draw then u have a short. Start disconnecting things one ata time while each time retesting the battery terminal for draw. When the draw stops then the last thing u disconnected is the culprit.

SOMEONE needs to out line this procedure as a standardized trouble shooting guide under some appropriate DF heading as such.

Of course since no one liked my idea of an X-ref i guess i'm just blowing smoke. OR maybe there is "no logical reason" for a general trouble shooting heading??

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Gary,

Your alt. has a very simple 3 wire system, But if the dash has a problem at the alt. bulb light, it will not charge. Does the light come on with the car not running? in key on or start position? Do you have Batt voltage at the big red wire at the back of the alt. and the fat wire in the 2 wire plug, engine not running? should be 12 volts all the time. with the key on you should see very low voltage at the small wire. this is taking a ground to the bulb/guage. when the car starts, it should send higher 14 volts to the guage/light if the alt is charging. Test the hots with the ground on the case of the alt., this gives you a true reading on the alt to engine ground. Hope this helps. Karl

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If the car does not charge when it is running and the battery does NOT discharge while sitting..and assuming a good battery....REPLACE THE ALT BELT shocked.gif I have twice had charging problems with alternators that baffeled me....and both times the belt was glazed/worn enough to slip and not spin the alt fast enough to to charge the car....Alt worked fine off the car, or when installed on another car (back when I had lots of time and NO $$$). Don't assume the belt is ok and don't tighten it up thinking it is now so tight that it can't slip..it can..and it can do it without squealing......hope this solves athe problem smile.gif

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Guest imported_PackardV8

Amen on reading the manuals! It always suprises me at how many people have owned a car or motorcycle for many years and do not have a manual. Thanks for the tip about Chiltons. I have several Chiltons manuals and never noticed that in there before or maybe forgot. But, then again, i have been guilty of tearing into a project myself without reading the manual too.

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Saw a Jag at a show once. Over the original LUCAS headlight switch the fellow had glued his own switchplate showing the three positions of the lights as "Off", "Dim", and "Flicker". I suspect he knew the meaning of "frustratinest". Don't get me wrong, I love the British and their cars. Heck, I'm even trying to learn their language. Have owned an XK150 since 1968 and have restored several British cars but some things I'll never understand. Restored a '37 Bentley a few years ago. Now, the technology to dim headlights isn't all that complicated is it ? Apparently not complicated enough for the folks at Bentley. They thought it better to mount solenoids in the headlights to physically "tilt" the reflectors when necessary.

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Dear Restorer32,Off topic,When i was in high school 1969,a buddys brother had a 1955? xk 120? Jag,couldn't beat the SOUND of that car,between the sound of the gear whine and exhaust together.YAHOOOOOOOOOOOOOOOOOOOOOO 30 years ago and i can still hear it.SHOULD i maybe go check into some kind of institution now.diz tongue.giflaugh.gif

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Terry's right. You don't need a bang. Get a buddy and use a test light with all power off, including ignition. Disconnect battery positive cable, place test light between the battery post and the cable. If the test light lights up, your car is drawing power from somewhere it shouldn't. Then process as another poster said with your buddy's eye on the test light. When the offending circuit is found, the light will go out. That's it guys. Wayne

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Saw a '19 Cadillac a few weeks back that had mechanical linkage from a rod under the dash to headlight buckets, for dimming lights. I think they even had grease fittings or tiny oil cups at all the pivot points.

I was told once that Southside Virginians and especially Coastal North Carolinians speak English closer to the Elizabethan and Scots tongue than any other group in the world.

Oi reckon they mought be roight. Come oht ta the hohse when ye can. Oi need sae help catchin a mohse.

(I think they may be right. Come out to the house when you can, I need some help catching a mouse.)

And people really do sound like that here.

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Until a few years after WW2, many British cars (including RR & Bentley) used the 'pass light' system. That 'fog light' in front of the radiator is a pass lamp; when you 'dip' the lights the headlights go off and the pass lamp comes on. I bet they didn't steal THAT idea from us!

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