Kharl Posted March 9, 2017 Share Posted March 9, 2017 Hi guysafter 4 years ofrandom battery discharges, two new batteries (one exploded), yesterday,the battery and brake lights came on, and today the vehicle shut offwhile running.everything points to the alternator but... i hadan used alternator in my house and i did the install, and jump start thecar and 10 minutes later int went off again, TWO ALTERNATORS?what other thing could cause the battery not charging? Quote Link to comment Share on other sites More sharing options...
lmdew Posted March 9, 2017 Share Posted March 9, 2017 Check the ground connections. I had one fellow here in town that had installed 4 different used Alt that I had for him. He finally brought the car over for me to look at. As I check the grounds, the main battery ground lead that bolts to the engine block bracket at the starter mount bolt was loose. When I pulled it off the bracket and terminal on the ground wire was all pitted. I changed the battery leads and bracket the problem was fixed. Larry Quote Link to comment Share on other sites More sharing options...
GreaseMonkey03 Posted March 9, 2017 Share Posted March 9, 2017 Battery could be shot too and not hold a charge. Ground or bad terminals as well but alternator could also be no good. Check the charge rate of the alternator and the cold cranking amps on the battery to eliminate those possibilities. Brake light is a separate issue. Check your brake fluid reservoir. If it's low, check your brake pads before you top it off. If they are fine, top it off. If your car has drums pull them off. A leaking wheel cylinder can cause fluid loss without having a big affect on your pedal pressure. Quote Link to comment Share on other sites More sharing options...
Kharl Posted March 9, 2017 Author Share Posted March 9, 2017 the battery is new and the alternator i am sure is not charging, but could something lese block the charge form alternator to battery, i mean could the alternator be good and the charge not passing to the battery due something extra? Quote Link to comment Share on other sites More sharing options...
DaveT Posted March 9, 2017 Share Posted March 9, 2017 You need a voltmeter. Need measurements to diagnose . Voltage at alternator output terminal Voltage on battery posts. At idle. At 1500 to 2000 rpm. And with car off. Quote Link to comment Share on other sites More sharing options...
Kharl Posted March 9, 2017 Author Share Posted March 9, 2017 You need a voltmeter. Need measurements to diagnose . Voltage at alternator output terminal Voltage on battery posts. At idle. At 1500 to 2000 rpm. And with car off. i can do tha right now those voltage at the alternator output, and battery.. were do i ge tit, putting the votlmeter pins on the battery poles (with cables on?) Quote Link to comment Share on other sites More sharing options...
DaveT Posted March 9, 2017 Share Posted March 9, 2017 The readings on the battery, probed right on the posts. Yrs everything wired as it should be. Alternator terminal to alternator frame. A bonus / double check put 1 probe on the alternator frame and the negative battery post Quote Link to comment Share on other sites More sharing options...
Kharl Posted March 9, 2017 Author Share Posted March 9, 2017 The readings on the battery, probed right on the posts. Yrs everything wired as it should be. Alternator terminal to alternator frame. A bonus / double check put 1 probe on the alternator frame and the negative battery post Great!! thank you a lot for your help need chelp, Sorry for my lack of experience "Alternator terminal to alternator frame." what is alternator terminal? the connector with 4 clamps (how could i doit without disconecting it then? or the bolted terminal? the last thing (the double check) is for checking continuitti right? Quote Link to comment Share on other sites More sharing options...
DaveT Posted March 9, 2017 Share Posted March 9, 2017 The reading for the alternator output is the one big bolted connection, fat wire. The last reading is voltage also, with the same conditions, idle, reved, off. Quote Link to comment Share on other sites More sharing options...
Kharl Posted March 9, 2017 Author Share Posted March 9, 2017 The reading for the alternator output is the one big bolted connection, fat wire. The last reading is voltage also, with the same conditions, idle, reved, off. give me 3 minutes i amgoing to doit Quote Link to comment Share on other sites More sharing options...
Kharl Posted March 9, 2017 Author Share Posted March 9, 2017 battery was dead so i am charging it (slow charge) thats why its voltage is 12.3 when i started the car the voltage drop and fixed at 11.87v voltage at alternator terminals 11.85v the earth is very good very low almost 0 resistence and the test of alternator frame to battery negative pole shows almsot 0 resistence... everything points to the alternator Quote Link to comment Share on other sites More sharing options...
DaveT Posted March 9, 2017 Share Posted March 9, 2017 12.3 at rest is very discharged. The alternator is not making power, for sure. Could be the alternator, or one of the small wires isn't doing what it should. One of those has to be a "turn on the regulator" / "key on" kind of control. I can't be specific without the fsm. The reason to measure voltage between the alternator frame and negative battery terminal is this. It should be near zero, but a few 10s of milli volts indicates current flow. Also, for high current paths, an ohm meter can give misleading results. An example would be a poor connection that will read zero ohms with the fraction of a milli amp that the meter uses, but goes open when you try to push 20amps through it. Quote Link to comment Share on other sites More sharing options...
Kharl Posted March 9, 2017 Author Share Posted March 9, 2017 those small wires you mention.. are all inside the alternator? my fear is if the problem is not the alternator neither the battry it scares me a lot that could be something else Quote Link to comment Share on other sites More sharing options...
GreaseMonkey03 Posted March 9, 2017 Share Posted March 9, 2017 There's not much else it can be aside from the alternator, battery, or cables. If the battery were dying while the car was off, then you could potentially have a draw somewhere in your system. But this would be a non issue with the car running. Since the car is dying while it's running, there's not much else other than the alternator, battery or connections that it could be. Wiggle the connectors on the battery too, sometimes the clamps stretch and even when tight will not grab the terminal properly. Once the battery is fully charged, hook it up and check the voltage between the negative and positive terminals on the battery at idle. Would also be a good idea to have the battery load tested. Could very well be a defective battery. Quote Link to comment Share on other sites More sharing options...
Kharl Posted March 9, 2017 Author Share Posted March 9, 2017 OK i need a reliable solution, a solution tha last at least for some nice years used alternators are a whole matter of luck, i have heard of used alternators that last 5 10 years and others that last only weeks.... the best solution would be a new enuine one but... before reaching that top solution... do you suggest me to try for a usend one? an dhow to choose one that could last? or.. i was watching this one on ebay, what do you think? http://www.ebay.com/itm/1992-Subaru-Legacy-H-4-2-2L-Engine-80AMP-Alternator-/190521461502?hash=item2c5bf6cafe:m:mgi-Sx1mwI30yJAe0Sej3IQ&vxp=mtr osed one sin my country ranging from 40-60us that one from ebay woul dcost me about us150 (with the shipping to Dominican Republic) Quote Link to comment Share on other sites More sharing options...
GreaseMonkey03 Posted March 9, 2017 Share Posted March 9, 2017 you have one other option. Take your other used alternator and have it rebuilt. If the priority is that it lasts, get one from Subaru. Can't predict how a used one will perform and can't guarantee how long aftermarket will last. Quote Link to comment Share on other sites More sharing options...
DaveT Posted March 9, 2017 Share Posted March 9, 2017 Oh, the small wires, there are usually at least 2 small wires from a connector on the alternator that go to the alternator light, ignition switch, etc. What exactly depends on the car. Going by the readings you gave above, the voltage is way low for with the engine running. The voltage on the alternator terminal reading lower than the battery post indicates no output from the alternator. So either te alternator is dead, or one of those small wires isn't doing what it supposed to. It would be worth checking fuses. Not with an ohm meter, not by looking at them, but by measuring each end to ground. With the engine running. Both sides / ends of a good fuse should read close to the same voltage. Quote Link to comment Share on other sites More sharing options...
Kharl Posted March 9, 2017 Author Share Posted March 9, 2017 Oh, the small wires, there are usually at least 2 small wires from a connector on the alternator that go to the alternator light, ignition switch, etc. What exactly depends on the car. Going by the readings you gave above, the voltage is way low for with the engine running. The voltage on the alternator terminal reading lower than the battery post indicates no output from the alternator. So either te alternator is dead, or one of those small wires isn't doing what it supposed to. It would be worth checking fuses. Not with an ohm meter, not by looking at them, but by measuring each end to ground. With the engine running. Both sides / ends of a good fuse should read close to the same voltage. what fuses? the ones in the cabin or the ones in the engine compartment? Quote Link to comment Share on other sites More sharing options...
DaveT Posted March 9, 2017 Share Posted March 9, 2017 Probably depends on the year and model of the car. I know the older Loyales and GLS best, the fuses for the control wires would be in the cabin. Having the factory service manual schematics of the wiring would be helpful. I have seen links to online download able ones for most Subarus in other threads. Quote Link to comment Share on other sites More sharing options...
DaveT Posted March 9, 2017 Share Posted March 9, 2017 I worded part of that oddly. The fuse isn't likely specific to the alternator, it is likely for engine systems power, and the alternator just happens to be one of the things fed by it. Quote Link to comment Share on other sites More sharing options...
Kharl Posted March 9, 2017 Author Share Posted March 9, 2017 I worded part of that oddly. The fuse isn't likely specific to the alternator, it is likely for engine systems power, and the alternator just happens to be one of the things fed by it. thats what i thought, i watche dall the fuses and none of them are named soethingrelated to alt or engine i have the service manual Quote Link to comment Share on other sites More sharing options...
DaveT Posted March 9, 2017 Share Posted March 9, 2017 Look for rhe engine electrical schematic. Find the alternator section. It might take a little tracing of lines, etc. To figure it out, but it should show what fuse is in the circuit. It should show what pins go where. On gemeral, 1 wire has to be going to the alternator light or indicator lights. One has to be fed power via the ignition switch. Those circuits have to be intact and functional for the alternator to work. Quote Link to comment Share on other sites More sharing options...
Kharl Posted March 9, 2017 Author Share Posted March 9, 2017 Look for rhe engine electrical schematic. Find the alternator section. It might take a little tracing of lines, etc. To figure it out, but it should show what fuse is in the circuit. It should show what pins go where. On gemeral, 1 wire has to be going to the alternator light or indicator lights. One has to be fed power via the ignition switch. Those circuits have to be intact and functional for the alternator to work. so, that should be locate dun der the dash right? and out of the fuse box Quote Link to comment Share on other sites More sharing options...
DaveT Posted March 9, 2017 Share Posted March 9, 2017 I need to know the model and year engine size, etc. of the car, and have the link to the fsm to be that specific. Quote Link to comment Share on other sites More sharing options...
Kharl Posted March 9, 2017 Author Share Posted March 9, 2017 I need to know the model and year engine size, etc. of the car, and have the link to the fsm to be that specific. its a Legacy 93 ej22 2.2 liters (i have checked all the fuses they all looks good Quote Link to comment Share on other sites More sharing options...
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