cookster Posted July 14, 2017 Share Posted July 14, 2017 Hi all. I've been away from the forum for a while, my son wrote off my 02 Outback about a year ago and I've been "Subaru-less" ever since. That being said, my nephew still has his 2000 Outback and since I'm the family mechanic, I still get to tinker from time. This morning when he went to start the car, the battery was dead, assuming it was a bad battery, he went out and bought a new one and the car started right up. I put a meter on the battery with the motor running and got only 13.2 volts (which is a little low in my experience) and I noticed the alternator was whining a little bit and was extremely hot to the touch after running for less than a minute. We then replaced the alternator and have the same issue, whining and getting very hot. I expect something is putting a huge draw on the system but I dont really know how to go about diagnosing it. So far I've pulled fuses one at a time with the motor running to see if I could isolate the problem but no luck. Hoping this problem may be common and that someone can offer some ideas. Thanks. Quote Link to comment Share on other sites More sharing options...
Rooster2 Posted July 14, 2017 Share Posted July 14, 2017 Whining can be caused by a bad bearing in the alternator. If so, it is likely the source of the noise, plus the added friction of the bad bearing is causing the heat build up. If you bought a rebuilt alternator from a chain parts store, it is possible that you got a bad one. The rebuilders often do a poor repair job, so I have found it takes another swap out to get a good one. Rather doubt that you have any huge electrical draw. If so, the electrical system would blow a fuse on a particular circuit. Quote Link to comment Share on other sites More sharing options...
cookster Posted July 14, 2017 Author Share Posted July 14, 2017 Thanks for the prompt reply. I have a bit of an update, I forgot to check the fuses under the hood so I pulled them one at a time and when I pulled one called Meter SRS lamp the noise went away completely. With that fuse pulled, however there was no output voltage. Just curious, would a bad bearing only be noisy under load? Quote Link to comment Share on other sites More sharing options...
idosubaru Posted July 14, 2017 Share Posted July 14, 2017 replaced the alternator with what, another used alternator that's been sitting? clean battery posts clean and tighten battery cables with a charged battery check voltage:A. at the clean battery posts (not the cable end attached to the battery) B. at the atternator C. at the starter D. at the main fuse box see if your voltages are clean across multiple areas. Quote Link to comment Share on other sites More sharing options...
Rooster2 Posted July 14, 2017 Share Posted July 14, 2017 Thanks for the prompt reply. I have a bit of an update, I forgot to check the fuses under the hood so I pulled them one at a time and when I pulled one called Meter SRS lamp the noise went away completely. With that fuse pulled, however there was no output voltage. Just curious, would a bad bearing only be noisy under load? No, a bad bearing would be noisy no matter what. Since pulling a fuse eliminates the noise, you have something else going on Quote Link to comment Share on other sites More sharing options...
cookster Posted July 14, 2017 Author Share Posted July 14, 2017 Sorry, should have clarified that the alternator we installed was a new re manufactured unit so we have a new alternator and a new battery. I'll run the voltage tests that have been suggested. Quote Link to comment Share on other sites More sharing options...
idosubaru Posted July 14, 2017 Share Posted July 14, 2017 if the cable ends are loose, corroded, dirty, or corrossion has crept up under the cable sheathing you'll have significant drops of voltage across some of those places mentioned. Quote Link to comment Share on other sites More sharing options...
Fairtax4me Posted July 14, 2017 Share Posted July 14, 2017 That's probably the fuse for the combination meter/instrument cluster. The charge warning lamp in the cluster supplies voltage for the field coil in the alternator, so pulling that fuse would keep the field from energizing and thus prevent charging. It sounds like you either have a short in the output, or the supply wire going to the regulator. The two small wires that plug into the back and the main output lead all go to the under hood fuse panel. Both of the small wires should show 12v with the key On. If the voltage is low there's a wire problem between the alt and the fuse box and that is the most likely cause of your overcurrent condition. 1 Quote Link to comment Share on other sites More sharing options...
cookster Posted July 14, 2017 Author Share Posted July 14, 2017 I checked the voltage on the two wires in the plug, one is constant 12 v and the other one is 12 v with key in run position so they seem to be okay. I guess the next step is to check for shorts. Thanks for the help guys. Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted July 14, 2017 Share Posted July 14, 2017 how is the car stored and used? any work or wrecks recently? ANY other electrical issues? odd brake, turn signal, parking light issues? original radio/head unit? Quote Link to comment Share on other sites More sharing options...
cookster Posted July 14, 2017 Author Share Posted July 14, 2017 how is the car stored and used? any work or wrecks recently? ANY other electrical issues? odd brake, turn signal, parking light issues? original radio/head unit? The car is a daily driver and is parked in an underground lot. No recent work done to the car and no accidents. Aftermarket radio installed by myself a year and a half ago using correct plug adapter. This problem occurred quite suddenly, the car was running perfectly the day before. Quote Link to comment Share on other sites More sharing options...
cookster Posted July 15, 2017 Author Share Posted July 15, 2017 Back at the car again this morning, it's 100 km away so it's a bit of a pain to say the least. Anyway, voltage at starter, battery and right athe alternator are all equal and I've confirmed that all connections are clean. I'm out of ideas. Quote Link to comment Share on other sites More sharing options...
DaveT Posted July 15, 2017 Share Posted July 15, 2017 Id.be looking for what may be causing a big load that is run via that fuse that made a difference. Have to determine if a lot of current is being drawn from the alternator output wire, or somehow you just got lucky and got a dead alternator. The whine and that much heat that quick is a sign of a heavy load or shorted rectifiers kind of failire. Quote Link to comment Share on other sites More sharing options...
cookster Posted July 15, 2017 Author Share Posted July 15, 2017 The fuse that I pulled actually stopped the alternator from charging all together which is why it stopped whining when I pulled it. Every other fuse in the car was pulled out one at a time in an attempt to isolate the circuit causing the problem but the noise persisted and no faulty circuit was identified. Quote Link to comment Share on other sites More sharing options...
cookster Posted July 15, 2017 Author Share Posted July 15, 2017 Trying to get ahold of another alternator to test in the car just to be sure that it's not the root cause. Original alternator and replacement one both exhibit the same condition so it's unlikely but not impossible. Quote Link to comment Share on other sites More sharing options...
DaveT Posted July 15, 2017 Share Posted July 15, 2017 2 things I'd likely try to attempt to get more information. . Wire a headlamp bulb in series with the alternator output. Depending on the current drawn, it will glow. Notice whine, or lack, and measure voltages. Also, disconnect the alternator output from the car's wiring, and just connect it to a separate headlamp bulb, other side of the bulb to ground. Again, check voltages and whine or not. Quote Link to comment Share on other sites More sharing options...
1 Lucky Texan Posted July 15, 2017 Share Posted July 15, 2017 take the suspect alternators to a shop for testing? Quote Link to comment Share on other sites More sharing options...
cookster Posted July 15, 2017 Author Share Posted July 15, 2017 Back home now and no luck with the issue. I hate giving up but working on a car 100 km from home without all my tools just sucks. The car is going to the shop next week. Once fixed,I'll be sure to post with the details. Thanks to all for the help. Quote Link to comment Share on other sites More sharing options...
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