Put on your Car Doctor hats, Bad Dog Denizens:

brillocaster · December 17th, 2007, 04:43 PM

I drive a 1992 Subaru Legacy wagon. Has about 245,000 miles on it. This summer it started having problems starting in the mornings and one morning the battery was so dead I could not jump the car.

Bought a new battery and everything was hunky dory for about a month. Go out November 1 to a stone-dead battery. I jump the car and take it to my buddy's house. We test the battery with the engine off...something like 0.3 volts coming out. Jump it and put the volt-meter on there...14 volts. We decide that the alternator is fine and that I got a dud battery from Autozone that won't hold a charge.

I take the 'dud' back to Autozone and the guy gives me a new one with absolutely no hassle (caught me a little off guard actually). Put that new one in and I'm back in business until....fast forward to about two weeks ago I go out to, you guessed it, a stone dead battery.

So, I have it narrowed down to three theories.

First, the alternator is dead/dying and the only reason it took it so long to die the first time is that I was making a 30 mile commute and I was getting a tiny bit of a charge on that long drive. Now that I live a couple miles from work there's virtually no charge time going on.

Second, maybe there's a loose belt in there.

Third, there's a short somewhere that is draining the battery when the car is not on.

Thoughts? I don't want to go out and buy a rebuilt alternator and spend an afternoon putting it in if that's not the problem. I wouldn't know how to find the short.

unclearty · December 17th, 2007, 04:47 PM

First..get a cheap 12 volt test light. Make sure the car is off and the key removed from the ignition. Remove the positive battery cable from the battery and connect the test light between the positive battery terminal and the positive cable. If the test light lights up brightly, you have a short. Check ALL interior lights..including the trunk area.

brillocaster · December 17th, 2007, 04:55 PM

Thank you unclearty! A 12v test light is cheaper than having it in to my mechanic for a day.

I had some electrical work done in the car last February (horn would randomly sound so had new button wired into the dash) and I suspect that if there is a short, that's a good candidate.

Boubou · December 17th, 2007, 04:58 PM

Had a similar problem, loose belt, not recharging.
With a brand new battery, after draining it good, i had to turn off the radio so the blinker had enough juice to blink.

Telenator · December 17th, 2007, 05:10 PM

I'd go with the "short in the electrical system" theory. Had the same problem several years ago. Turns out it was a defective aftermarket alarm system that was killing the battery even when it wasn't on. Check your aftermarket accessories, if any.

TDPRI · December 17th, 2007, 05:38 PM

I'd go with the dead Alternator. You need a amp meter to see how many amps you're putting out. Take it to a 30 min oil change kind of place, or even Autozone they can tell you quickly and cheaply if it's the alternator. But if you haven't replaced the alternator in 245K miles I'd go with that for darn sure.

Sure it could be the other things... but if its a dead short then your lights would be dim. If it was a belt it would be screeching.

Alternator... the most expensive of the three. No, I take that back. All three. That would be the most expensive.

younkint · December 17th, 2007, 05:40 PM

All the above suggestions are good. I'm wondering though, are all those 245K miles yours? Or can you vouch for, say, everything past 100K or so? I ask this because 245K is a l-o-o-o-o-o-n-n-n-g way to go without an alternator failing. If you have never replaced it, I would consider it highly suspect. I don't have access to my data right now, but I think by '92 the voltage regulator was built in to the alternator, so a new alternator would cover any regulator issue.

Do you have an "idiot light" or a gauge showing alternator failure? If you have an idiot light, fire up the car and check that light in the dark - if you see faint glowing of that light (not a bright glow, but a noticeable glow), then I believe you are in the market for an alternator. A faint glow in the idiot light shows a failed diode in the rectifier circuit. Don't be fooled by your dash lights "leaking" into the alternator idiot light; be sure everything is off when you check. Even if you do not see the faint glow, the alternator can still have failed.

Having said all that, check your cables... simple corrosion can easily cause this. If the cable fittings are crimped with bolted crimps, check that. All white powder is bad news. Are things actually tight, or do they just look tight? Grab things and pull ...not the small wires - just the big cables. Be careful - that cable from the battery to the alternator is live and would just love to melt your jewelry if you give it a good ground.

Further, be aware that these days many good auto parts stores will actually come out to your vehicle at the store and hook up some modern diagnostics (that may save you a mechanic$ bill).

boris bubbanov · December 17th, 2007, 05:54 PM

Quote:

Originally Posted by younkint

Further, be aware that these days many good auto parts stores will actually come out to your vehicle at the store and hook up some modern diagnostics (that may save you a mechanic$ bill).

This is a great plan.

About the alternator itself; I know of cars with over 400,000 miles on the original alternator, it depends on the source how long they can last.

And I agree about the loose or corroded connections in the charging circuit. That's my first choice, second is the alternator (bearings or diodes) and third is a short circuit.

Tug on that alternator drive belt; if not fairly loose it won't be that, at least not alone. Actually depending on what else, if anything, the alternator drive belt drives, the bearings on another accessory could keep the belt from pulling normally, but it'd burn up the belt usually in that case.

Good luck.

Bubbanov

younkint · December 17th, 2007, 06:02 PM

Quote:

Originally Posted by boris bubbanov

About the alternator itself; I know of cars with over 400,000 miles on the original alternator, it depends on the source how long they can last.

Tug on that alternator drive belt; if not fairly loose it won't be that, at least not alone. Actually depending on what else, if anything, the alternator drive belt drives, the bearings on another accessory could keep the belt from pulling normally, but it'd burn up the belt usually in that case.

Good luck.

Bubbanov

Boris is right in what he says. Most of my Japanese vehicles had their alternators fail right around your mileage, though. I did have an old GMC that went to nearly 300K before it bit the dust.

What Boris said made me think: Go out and actually look at the alternator pulley while the engine is running ...is it actually turning, or is the alternator frozen? It happened to me, and the belt never did squeal.

Scoot · December 17th, 2007, 06:51 PM

Well sort of, it's called a parasitic draw. Something is drawing the juice out of the battery. Do the test unclearty said to do, only it should be done on the
negative side of the battery. The light will glow bright if you have a draw, and
next is to isolate by removing fuses 1 at a time. When the light goes out or gets very, very dim, the last fuse you pulled is the culprit circuit. Look in yer owners manual to see what that fuse powers to further isolate the draw.
The 2 most common problems are cigarette lighters or things plugged into them or hidden courtesy lights (Glove box, underhood) Keep in mind certain
things like the radio memory do draw aprox. 5 Ma. which will make the light
light up very dim. I know it sound like alot of work, but thats how we have to
do it. Also if the light does not go out by pulling fuses, disconnect the alter-
nator at the plug in on the back, if the light goes out it's the diodes in it and
you need a new alt.
Feel free to PM me for more info or schematics.
ASE, GM, Chrysler Auto Technician for 20+ yrs.

younkint · December 17th, 2007, 07:08 PM

Quote:

Originally Posted by Scoot

Feel free to PM me for more info or schematics.
ASE, GM, Chrysler Auto Technician for 20+ yrs.

^^^ There's the man that will know!

~

Mark Davis · December 17th, 2007, 07:33 PM

I had the same problem with my 53 Ford Business coupe.

After replacing 2 batteries and 1 voltage regulator and 2 generators rewound I found out there was a short in thr horn relay that was a constant drain on the system.

PraiseCaster · December 17th, 2007, 07:34 PM

First suspect in my book would be the Alternator (its got 245,000 miles spun on it, its gotta be shot). Second is the parasitic draw.

But I would check for the parasitic draw first, then if that checks out, I'd replace the alternator (nope, wouldnt even check it).

Scoot · December 17th, 2007, 07:54 PM

I come here for all you guys knowledge, So I only hope I can return the favor.
I know how hard it is to pay the LONG dollar for a mechanic, but we don't
make nearly as much as you're charged for at a shop or ESP. Dealer!
I just wanna return the knowledge favor.

0le FUZZY · December 17th, 2007, 08:29 PM

...Blown diode inna alternator. Onlee takes won!!

0.F.

brillocaster · December 17th, 2007, 11:04 PM

Thanks everyone for your responses! Yeah, i bought the car in 1994 with ~30k miles on it, so 215k of them are on me. The alternator in it now is the one it left the factory with.

Not enough light for me to try all those tricks when I got home tonight...I'll take a whack at it at lunch tomorrow. Most likely I will take it to the mechanics (happily right across the street from work) anyway - need it fixed right, right away.

scooteraz · December 18th, 2007, 12:26 AM

I saw this earlier in the day, but did not have time to respond. You got good advice from Scoot and from Ole FUZZY. However, there is one other possibility. Bad voltage regulator. Not too little voltage, but too much (can happen under load as well as unloaded). To check, you need to have the car running, and an assistant. Load up everything (headlights, radio, wipers, fans, whatever you can turn on). Have the assistant run the engine at about road speed, say 2500-3500 rpm. Check the voltage. Unload, run the car at the same speed and check again. You should not have much more than 16 volts, ever. If you do, then the voltage regulator (today usaually a chip in the alternator) is bad and you are actually cooking your batteries from the over-charging. Batteries can take 18-20 in short bursts, but above that start loosing water, then they just won't charge. Takes about 1-3 months.

How do I know? I have the T-shirt, and more than one.

brillocaster · December 18th, 2007, 05:23 PM

Update: Parasitic draw for the win! And what's more, it was exactly the horn wiring that I ref'd above that was the culprit. Ended up costing me 1 hr. of mechanics time to get it resolved.

Thanks, everyone!

Mark Davis · December 18th, 2007, 06:07 PM

Quote:

Originally Posted by brillocaster

Update: Parasitic draw for the win! And what's more, it was exactly the horn wiring that I ref'd above that was the culprit. Ended up costing me 1 hr. of mechanics time to get it resolved.

Thanks, everyone!

So do I get a prize for winning? LOL

Glad you got it fixed.

Wildhawk · December 18th, 2007, 06:13 PM

Quote:

Originally Posted by unclearty

First..get a cheap 12 volt test light. Make sure the car is off and the key removed from the ignition. Remove the positive battery cable from the battery and connect the test light between the positive battery terminal and the positive cable. If the test light lights up brightly, you have a short. Check ALL interior lights..including the trunk area.

+1

benbo · December 18th, 2007, 06:15 PM

Quote:

Originally Posted by unclearty

First..get a cheap 12 volt test light. Make sure the car is off and the key removed from the ignition. Remove the positive battery cable from the battery and connect the test light between the positive battery terminal and the positive cable. If the test light lights up brightly, you have a short. Check ALL interior lights..including the trunk area.

I was a dealership Mechanic for 10 years and this is exactly what I would think first off, being that when the car is running the ALT puts out 13 to 14 volts, I would at first have maybe suspected a bad battery but not 2 or 3 in a row.

A battery drain will cause this and add in cooler or cold weather and the battery will dye even faster with a drain.

Scoot · December 19th, 2007, 07:19 PM

Yeah, But I was the one who knew it was a parasitic draw.
So I guess we'll have to split that prize. Hee Hee Hee, just kidding.
Glad ya got it fixed for only an hours labor, sometimes they can be a real
pain in the "Keister" to isolate, and take hours and hours.

December 17th, 2007, 04:43 PM	#1 (permalink)
brillocaster Tele-Holic Join Date: Jun 2006 Location: Richmond, VA Posts: 750	Put on your Car Doctor hats, Bad Dog Denizens: I drive a 1992 Subaru Legacy wagon. Has about 245,000 miles on it. This summer it started having problems starting in the mornings and one morning the battery was so dead I could not jump the car. Bought a new battery and everything was hunky dory for about a month. Go out November 1 to a stone-dead battery. I jump the car and take it to my buddy's house. We test the battery with the engine off...something like 0.3 volts coming out. Jump it and put the volt-meter on there...14 volts. We decide that the alternator is fine and that I got a dud battery from Autozone that won't hold a charge. I take the 'dud' back to Autozone and the guy gives me a new one with absolutely no hassle (caught me a little off guard actually). Put that new one in and I'm back in business until....fast forward to about two weeks ago I go out to, you guessed it, a stone dead battery. So, I have it narrowed down to three theories. First, the alternator is dead/dying and the only reason it took it so long to die the first time is that I was making a 30 mile commute and I was getting a tiny bit of a charge on that long drive. Now that I live a couple miles from work there's virtually no charge time going on. Second, maybe there's a loose belt in there. Third, there's a short somewhere that is draining the battery when the car is not on. Thoughts? I don't want to go out and buy a rebuilt alternator and spend an afternoon putting it in if that's not the problem. I wouldn't know how to find the short. __________________ ************************** Make it have many characteristicses of these musical instruments, include the quasi- and generous sound area and vivid key of specially accurate sound to respond, can give musical performance to start out to hear easily thus of voice!

December 17th, 2007, 04:47 PM	#2 (permalink)
unclearty Tele-Meister Join Date: Feb 2006 Location: South central Mass. Age: 56 Posts: 351 2 Photos	First..get a cheap 12 volt test light. Make sure the car is off and the key removed from the ignition. Remove the positive battery cable from the battery and connect the test light between the positive battery terminal and the positive cable. If the test light lights up brightly, you have a short. Check ALL interior lights..including the trunk area. __________________ uncle-arty

December 17th, 2007, 04:55 PM	#3 (permalink)
brillocaster Tele-Holic Join Date: Jun 2006 Location: Richmond, VA Posts: 750	Thank you unclearty! A 12v test light is cheaper than having it in to my mechanic for a day. I had some electrical work done in the car last February (horn would randomly sound so had new button wired into the dash) and I suspect that if there is a short, that's a good candidate. __________________ ************************** Make it have many characteristicses of these musical instruments, include the quasi- and generous sound area and vivid key of specially accurate sound to respond, can give musical performance to start out to hear easily thus of voice!

December 17th, 2007, 05:10 PM	#5 (permalink)
Telenator Friend of Leo's Join Date: Sep 2005 Location: Connecticut Posts: 4,662	I'd go with the "short in the electrical system" theory. Had the same problem several years ago. Turns out it was a defective aftermarket alarm system that was killing the battery even when it wasn't on. Check your aftermarket accessories, if any. __________________ Dogs have the right idea!

December 17th, 2007, 05:40 PM	#7 (permalink)
younkint Tele-Meister Join Date: Oct 2007 Location: Spring, Texas Age: 55 Posts: 276	All the above suggestions are good. I'm wondering though, are all those 245K miles yours? Or can you vouch for, say, everything past 100K or so? I ask this because 245K is a l-o-o-o-o-o-n-n-n-g way to go without an alternator failing. If you have never replaced it, I would consider it highly suspect. I don't have access to my data right now, but I think by '92 the voltage regulator was built in to the alternator, so a new alternator would cover any regulator issue. Do you have an "idiot light" or a gauge showing alternator failure? If you have an idiot light, fire up the car and check that light in the dark - if you see faint glowing of that light (not a bright glow, but a noticeable glow), then I believe you are in the market for an alternator. A faint glow in the idiot light shows a failed diode in the rectifier circuit. Don't be fooled by your dash lights "leaking" into the alternator idiot light; be sure everything is off when you check. Even if you do not see the faint glow, the alternator can still have failed. Having said all that, check your cables... simple corrosion can easily cause this. If the cable fittings are crimped with bolted crimps, check that. All white powder is bad news. Are things actually tight, or do they just look tight? Grab things and pull ...not the small wires - just the big cables. Be careful - that cable from the battery to the alternator is live and would just love to melt your jewelry if you give it a good ground. Further, be aware that these days many good auto parts stores will actually come out to your vehicle at the store and hook up some modern diagnostics (that may save you a mechanic$ bill). __________________ . -- Terry

December 17th, 2007, 04:58 PM	#4 (permalink)
Boubou Tele-Holic Join Date: Jul 2005 Location: Montreal, Quebec Age: 49 Posts: 678	Had a similar problem, loose belt, not recharging. With a brand new battery, after draining it good, i had to turn off the radio so the blinker had enough juice to blink.

December 17th, 2007, 05:38 PM	#6 (permalink)
TDPRI Administrator Poster Extraordinaire Join Date: Mar 2003 Location: TDPRILAND Posts: 5,582 36 Photos	I'd go with the dead Alternator. You need a amp meter to see how many amps you're putting out. Take it to a 30 min oil change kind of place, or even Autozone they can tell you quickly and cheaply if it's the alternator. But if you haven't replaced the alternator in 245K miles I'd go with that for darn sure. Sure it could be the other things... but if its a dead short then your lights would be dim. If it was a belt it would be screeching. Alternator... the most expensive of the three. No, I take that back. All three. That would be the most expensive.

December 17th, 2007, 06:51 PM	#10 (permalink)
Scoot Tele-Meister Join Date: Nov 2004 Location: Republik of Vermont Age: 43 Posts: 236	you have a parasite! Well sort of, it's called a parasitic draw. Something is drawing the juice out of the battery. Do the test unclearty said to do, only it should be done on the negative side of the battery. The light will glow bright if you have a draw, and next is to isolate by removing fuses 1 at a time. When the light goes out or gets very, very dim, the last fuse you pulled is the culprit circuit. Look in yer owners manual to see what that fuse powers to further isolate the draw. The 2 most common problems are cigarette lighters or things plugged into them or hidden courtesy lights (Glove box, underhood) Keep in mind certain things like the radio memory do draw aprox. 5 Ma. which will make the light light up very dim. I know it sound like alot of work, but thats how we have to do it. Also if the light does not go out by pulling fuses, disconnect the alter- nator at the plug in on the back, if the light goes out it's the diodes in it and you need a new alt. Feel free to PM me for more info or schematics. ASE, GM, Chrysler Auto Technician for 20+ yrs. __________________ Scoot If I Have to Explain, You Wouldn't Understand!!!

December 17th, 2007, 07:33 PM	#12 (permalink)
Mark Davis Doctor of Teleocity Join Date: Mar 2003 Location: Bakersfield Ca. Age: 58 Posts: 12,858	I had the same problem with my 53 Ford Business coupe. After replacing 2 batteries and 1 voltage regulator and 2 generators rewound I found out there was a short in thr horn relay that was a constant drain on the system. __________________ I'm so blind my seeing eye dog needs glasses.

December 17th, 2007, 07:34 PM	#13 (permalink)
PraiseCaster Friend of Leo's Join Date: Mar 2003 Location: Whittier, California Posts: 4,350 16 Photos	First suspect in my book would be the Alternator (its got 245,000 miles spun on it, its gotta be shot). Second is the parasitic draw. But I would check for the parasitic draw first, then if that checks out, I'd replace the alternator (nope, wouldnt even check it). __________________ Later! PraiseCaster Visit Guitarists Praise and Worship Forum!! Dance Like David, MySpace

December 17th, 2007, 07:54 PM	#14 (permalink)
Scoot Tele-Meister Join Date: Nov 2004 Location: Republik of Vermont Age: 43 Posts: 236	Thanks Younkint! I come here for all you guys knowledge, So I only hope I can return the favor. I know how hard it is to pay the LONG dollar for a mechanic, but we don't make nearly as much as you're charged for at a shop or ESP. Dealer! I just wanna return the knowledge favor. __________________ Scoot If I Have to Explain, You Wouldn't Understand!!!

December 17th, 2007, 08:29 PM	#15 (permalink)
0le FUZZY Doctor of Teleocity Join Date: Mar 2003 Location: Kolly-forn-knee-ya Posts: 10,001 6 Photos	...Blown diode inna alternator. Onlee takes won!! 0.F.

December 17th, 2007, 11:04 PM	#16 (permalink)
brillocaster Tele-Holic Join Date: Jun 2006 Location: Richmond, VA Posts: 750	Thanks everyone for your responses! Yeah, i bought the car in 1994 with ~30k miles on it, so 215k of them are on me. The alternator in it now is the one it left the factory with. Not enough light for me to try all those tricks when I got home tonight...I'll take a whack at it at lunch tomorrow. Most likely I will take it to the mechanics (happily right across the street from work) anyway - need it fixed right, right away. __________________ ************************** Make it have many characteristicses of these musical instruments, include the quasi- and generous sound area and vivid key of specially accurate sound to respond, can give musical performance to start out to hear easily thus of voice!

December 18th, 2007, 12:26 AM	#17 (permalink)
scooteraz Tele-Holic Join Date: Apr 2007 Location: Peoria, AZ Posts: 778	I saw this earlier in the day, but did not have time to respond. You got good advice from Scoot and from Ole FUZZY. However, there is one other possibility. Bad voltage regulator. Not too little voltage, but too much (can happen under load as well as unloaded). To check, you need to have the car running, and an assistant. Load up everything (headlights, radio, wipers, fans, whatever you can turn on). Have the assistant run the engine at about road speed, say 2500-3500 rpm. Check the voltage. Unload, run the car at the same speed and check again. You should not have much more than 16 volts, ever. If you do, then the voltage regulator (today usaually a chip in the alternator) is bad and you are actually cooking your batteries from the over-charging. Batteries can take 18-20 in short bursts, but above that start loosing water, then they just won't charge. Takes about 1-3 months. How do I know? I have the T-shirt, and more than one.

December 18th, 2007, 05:23 PM	#18 (permalink)
brillocaster Tele-Holic Join Date: Jun 2006 Location: Richmond, VA Posts: 750	Update: Parasitic draw for the win! And what's more, it was exactly the horn wiring that I ref'd above that was the culprit. Ended up costing me 1 hr. of mechanics time to get it resolved. Thanks, everyone! __________________ ************************** Make it have many characteristicses of these musical instruments, include the quasi- and generous sound area and vivid key of specially accurate sound to respond, can give musical performance to start out to hear easily thus of voice!

December 19th, 2007, 07:19 PM	#22 (permalink)
Scoot Tele-Meister Join Date: Nov 2004 Location: Republik of Vermont Age: 43 Posts: 236	Yeah, But I was the one who knew it was a parasitic draw. So I guess we'll have to split that prize. Hee Hee Hee, just kidding. Glad ya got it fixed for only an hours labor, sometimes they can be a real pain in the "Keister" to isolate, and take hours and hours. __________________ Scoot If I Have to Explain, You Wouldn't Understand!!!