Megell Posted June 10, 2009 Share Posted June 10, 2009 5 days ago, I installed a new battery as my old one died while parked in front of my house. Today, my engine began missing and finally died not far from my house. I tried to start it and the solenoid just clicked and I knew the new battery was dead. My question is, would the alternator in good working order deliver enough juice to keep the car running, even though the battery was low? My car is a 91 Legacy EJ22T sedan. It been well maintained with new T Belts etc; 187K and no alt. dash light on when running. Battery cables are clean. Any thoughts would be greatly appreciated. Thanks, Mike Quote Link to comment Share on other sites More sharing options...
bheinen74 Posted June 10, 2009 Share Posted June 10, 2009 are your cables connected very tightly to the battery? Quote Link to comment Share on other sites More sharing options...
J A Blazer Posted June 10, 2009 Share Posted June 10, 2009 I predict that you will discover that your alternator has failed. Happened to me, in a manner much as you describe. Quote Link to comment Share on other sites More sharing options...
davebugs Posted June 10, 2009 Share Posted June 10, 2009 Classic alternator symptoms on a Suby. Often when driving suddenly your maximum RPM's keep deminishing (because it isn't charging the battery). Shut it off and leave set a while if it's a good battery it'll start back up and you can head down the road again - for a while. Then the good battery looses it's charge again. Repeat the whole way home (I gave up and called a friend after 4 segments). Change fuel filter (figure it's running out of fuel), check fuel pump, check cats for blockage. Doesn't help. Install a new alternator and all is good. I've had this happen to me almost a half dozen times. Also sometimes the ABS and another light seem to come on in Suby's if the current is wimpy. Quote Link to comment Share on other sites More sharing options...
nipper Posted June 10, 2009 Share Posted June 10, 2009 The battery is used for starting, and the Alt is used to run the car. The Battery is used to suppliment the power if the Alt is not capable of meeting demand. IE a dead alt. Check the on line dealers for a Alt. You can get a much better value then what most chain autopart stores try to pass off as a rebuild. They also can be very reasonable. nipper Quote Link to comment Share on other sites More sharing options...
Rooster2 Posted June 10, 2009 Share Posted June 10, 2009 My thoughts like others, the alternator is bad, maybe putting out some current, but not enough to keep the battery charged. Change your alternator, and all should be well. Quote Link to comment Share on other sites More sharing options...
Megell Posted June 10, 2009 Author Share Posted June 10, 2009 are your cables connected very tightly to the battery? Cables are clean and tight. Quote Link to comment Share on other sites More sharing options...
Megell Posted June 10, 2009 Author Share Posted June 10, 2009 I predict that you will discover that your alternator has failed. Happened to me, in a manner much as you describe. Did your Amp gauge light come on when that happened. Mine is not on. Quote Link to comment Share on other sites More sharing options...
Megell Posted June 10, 2009 Author Share Posted June 10, 2009 Classic alternator symptoms on a Suby. Often when driving suddenly your maximum RPM's keep deminishing (because it isn't charging the battery). Shut it off and leave set a while if it's a good battery it'll start back up and you can head down the road again - for a while. Then the good battery looses it's charge again. Repeat the whole way home (I gave up and called a friend after 4 segments). Change fuel filter (figure it's running out of fuel), check fuel pump, check cats for blockage. Doesn't help. Install a new alternator and all is good. I've had this happen to me almost a half dozen times. Also sometimes the ABS and another light seem to come on in Suby's if the current is wimpy. Thanks, I noticed that just before the old battery died, the car had similar miss symtoms, but this time the engine eventuall died immediately after making a left turn at a very big and busy intersection. How do you tell if the alt is putting out if there is no amp light on? Quote Link to comment Share on other sites More sharing options...
Megell Posted June 10, 2009 Author Share Posted June 10, 2009 The battery is used for starting, and the Alt is used to run the car. The Battery is used to suppliment the power if the Alt is not capable of meeting demand. IE a dead alt. Check the on line dealers for a Alt. You can get a much better value then what most chain autopart stores try to pass off as a rebuild. They also can be very reasonable. nipper Thanks, Nipper. Any suggestions on where to go online to order a reliable alt? Quote Link to comment Share on other sites More sharing options...
98sub2500leg Posted June 10, 2009 Share Posted June 10, 2009 (edited) I also agree, classic alternator symptoms. Most auto parts stores can quickly test it to be sure. It is rare for a alternator winding to go bad unless it has been subjected to unusually high heat for several years. Some alternator manufacturers use a single layer of magnet wire insulation. Lifetime warrantee types use a much higher temperature or heavy insulation on the magnet wire to wind the stator. You can usually save many $$ by keeping the core(alternator housing & winding) and changing out just the rectifier(diode) pack and voltage regulator if available and brushes. If you do decide to do it, you will need a simple multimeter, possibly a soldering iron depending on the type of alternator, some use terminals and others you have to desolder. If it is the solder type, you will need a small piece of solder to re-tin the leads with flux for re-assembly. You will also need some small metric sockets (at least an 8mm), and a very small amount of bearing grease. If you haven't dome it before, document the disassembly well and or take pictures. PM me if you decide to go this route, I can walk you through it. Edited June 10, 2009 by 98sub2500leg clarification Quote Link to comment Share on other sites More sharing options...
98sub2500leg Posted June 10, 2009 Share Posted June 10, 2009 (edited) removed accidental double post Edited June 10, 2009 by 98sub2500leg accidental double post Quote Link to comment Share on other sites More sharing options...
Megell Posted June 10, 2009 Author Share Posted June 10, 2009 I also agree, classic alternator symptoms. Most auto parts stores can quickly test it to be sure. It is rare for a alternator winding to go bad unless it has been subjected to unusually high heat for several years. Some alternator manufacturers use a single layer of magnet wire insulation. Lifetime warrantee types use a much higher temperature or heavy insulation on the magnet wire to wind the stator. You can usually save many $$ by keeping the core(alternator housing & winding) and changing out just the rectifier(diode) pack and voltage regulator if available and brushes. Thanks for that information on rebuilding it. It's been many years since I rebuilt an Alt, but maybe that's an option if I can get the parts that you suggested. Also, Is there a simple was of checking the voltage output on my present alt? I have a voltmeter. Quote Link to comment Share on other sites More sharing options...
Olnick Posted June 10, 2009 Share Posted June 10, 2009 Any suggestions on where to go online to order a reliable alt? Call Jason at 866-528-5282, he's Parts Manager at Mike Scarff Subaru in Auburn WA. Usually has best prices for OEM . . . mention USMB. Another approach is to find an auto electric shop in your area and get a rebuilt alt. I've had excellent results doing this with electricals. Ask an indy shop or gas station mechanic for recommendations--there's usually one well thought of shop around. Quote Link to comment Share on other sites More sharing options...
Megell Posted June 11, 2009 Author Share Posted June 11, 2009 Call Jason at 866-528-5282, he's Parts Manager at Mike Scarff Subaru in Auburn WA. Usually has best prices for OEM . . . mention USMB. Another approach is to find an auto electric shop in your area and get a rebuilt alt. I've had excellent results doing this with electricals. Ask an indy shop or gas station mechanic for recommendations--there's usually one well thought of shop around. Thanks, I'll give Jason a call for price. Also, I now live in Tucson and there are all kinds of auto/ auto electrical shops locally. I'm new to the area, so I'm still learning where the best automotive places are. It would be nice not having to change the alt. twice by making a wrong choice. Quote Link to comment Share on other sites More sharing options...
98sub2500leg Posted June 11, 2009 Share Posted June 11, 2009 Thanks for that information on rebuilding it. It's been many years since I rebuilt an Alt, but maybe that's an option if I can get the parts that you suggested. Also, Is there a simple was of checking the voltage output on my present alt? I have a voltmeter. To start, make sure you have a charged battery. Measure the battery voltage when the car is off. A well charged battery should measure around 12.5-12.8vdc at room temperature (no load). When the engine is running and the alternator is charging normally it should measure 13.5-13.8vdc at the battery terminals. If it fluctuates wildly, it is more than likely the voltage regulator. If this test fails, it should only take approx. 10-15 minutes to remove it, take it to your local auto parts store to have it tested. Quote Link to comment Share on other sites More sharing options...
edrach Posted June 11, 2009 Share Posted June 11, 2009 To start, make sure you have a charged battery. Measure the battery voltage when the car is off. A well charged battery should measure around 12.5-12.8vdc at room temperature (no load). When the engine is running and the alternator is charging normally it should measure 13.5-13.8vdc at the battery terminals. If it fluctuates wildly, it is more than likely the voltage regulator. If this test fails, it should only take approx. 10-15 minutes to remove it, take it to your local auto parts store to have it tested.Just add to the test, run the rpm up to 3000 and watch the voltage across the battery; it should climb up to a maximum of around 14.5VDC. A better test is to repeat the same voltage tests with the headlights on high beam and as many other current loads you can add (blower, brake lights, etc.); you should get similar results if the alternator is working up to snuff. Quote Link to comment Share on other sites More sharing options...
Megell Posted June 11, 2009 Author Share Posted June 11, 2009 (edited) To start, make sure you have a charged battery. Measure the battery voltage when the car is off. A well charged battery should measure around 12.5-12.8vdc at room temperature (no load). When the engine is running and the alternator is charging normally it should measure 13.5-13.8vdc at the battery terminals. If it fluctuates wildly, it is more than likely the voltage regulator. If this test fails, it should only take approx. 10-15 minutes to remove it, take it to your local auto parts store to have it tested. Right now, battery tests 12.68v with engine off. Start engine and meter show 12.26v. Rev engine, no relevant change. Shut engine off and test battery again and it shows 12.44v. So, I guess that suggests either alt not working or voltage is not getting to the battery. I think I'm going with the bad alt since cable and connection seem ok. Thanks for all the helpful information everyone. Mike Edited June 11, 2009 by Megell Quote Link to comment Share on other sites More sharing options...
OB99W Posted June 11, 2009 Share Posted June 11, 2009 Right now, battery tests 12.68v with engine off. Start engine and meter show 12.26v. Rev engine, no relevant change. Shut engine off and test battery again and it shows 12.44v. So, I guess that suggests either alt not working or voltage is not getting to the battery. I think I'm going with the bad alt since cable and connection seem ok. It's obvious that the alt has insufficient or no output. Alternator field current initially comes from the battery (until the alt puts out enough), through the dash charge warning light. If the charge light and the brake warning light are lit with the engine running, that's a pretty sure sign that the alternator is bad. However, if there's no alternator output, but the charge light is not lit (as is apparently the case) with the engine running, then the alternator itself isn't necessarily the cause. Before you condemn the alternator, please tell us whether the charge light and the brake light come on when you turn the ignition switch to the ''ON'' position (but don't start the engine). Based on your answer, I might have other questions or suggestions of things to check. Quote Link to comment Share on other sites More sharing options...
Megell Posted June 11, 2009 Author Share Posted June 11, 2009 It's obvious that the alt has insufficient or no output. Alternator field current initially comes from the battery (until the alt puts out enough), through the dash charge warning light. If the charge light and the brake warning light are lit with the engine running, that's a pretty sure sign that the alternator is bad. However, if there's no alternator output, but the charge light is not lit (as is apparently the case) with the engine running, then the alternator itself isn't necessarily the cause. Before you condemn the alternator, please tell us whether the charge light and the brake light come on when you turn the ignition switch to the ''ON'' position (but don't start the engine). Based on your answer, I might have other questions or suggestions of things to check. When I turn the ignition to on, I get the normal bat, oil, brake etc; so I know the lights work. I start the car and all lights go out as they should. There is not brake light or bat. on while the engine is running. Everything seems normal. Quote Link to comment Share on other sites More sharing options...
OB99W Posted June 11, 2009 Share Posted June 11, 2009 When I turn the ignition to on, I get the normal bat, oil, brake etc; so I know the lights work. I start the car and all lights go out as they should. There is not brake light or bat. on while the engine is running. Everything seems normal. That's not the typical alternator failure that we see, although the alt could still be bad. Could you start the car once more, and measure the voltage (to ground) at the alternator's output terminal (not at the battery)? Quote Link to comment Share on other sites More sharing options...
Megell Posted June 11, 2009 Author Share Posted June 11, 2009 That's not the typical alternator failure that we see, although the alt could still be bad. Could you start the car once more, and measure the voltage (to ground) at the alternator's output terminal (not at the battery)? I thought it was a little weird that the dash amp lite did Not come on when the alt. failed. I guess I'm just used to a dash gauges to give me an indication of whats going on under the hood. Personally, what good is the gauge if it's not doing it's intended purpose. But that's just me. OK, so this morning after doing some local research for alt's her in Tucson, I went to a place called ..uh...Tucson Alternator Inc. and they had one in stock for $120. with a year warranty. Several places I talked to recommended them as they are the rebuilders. I replaced the alt. and started the car and got a reading of 14 + volts at the batt. terminals. This indicates to me that the alt. was indeed bad and not the wiring between. I really appreciate everyone's help and suggestions and it really helped me to fix my car with the least amount of inconvenience. Thank you so much. Mike Quote Link to comment Share on other sites More sharing options...
Rooster2 Posted June 11, 2009 Share Posted June 11, 2009 Glad you got the problem fixed. Glad we could offer advise. Happy Subie motoring! Quote Link to comment Share on other sites More sharing options...
Olnick Posted June 11, 2009 Share Posted June 11, 2009 I replaced the alt. and started the car and got a reading of 14 + volts at the batt. terminals. Congrats! What a great feeling! Quote Link to comment Share on other sites More sharing options...
nipper Posted June 11, 2009 Share Posted June 11, 2009 i use www.1stsubaru.com alot. there is also https://www.subarugenuineparts.com Quote Link to comment Share on other sites More sharing options...
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