2010 legacy 2.5, rats chewed alternator plug, temp fixed months ago, alt charging @ 15.5, battery light constantly on, a week or so ago light went out, car died sometime later. I just replaced alt w/maniacelecmotors after market, also the pigtail. Now I do not show alt charging. I read the battery indicator light has to work for charging. I need to remove panel to change bulb, I assume.

Can anyone advise me how to do this and am I correct? How is the panel removed and can this be done by a shade tree?

Test the bulb by turning the key on/eng. off

 

Then ground the charge light wire of the alt (Black/white on 90's cars..not sure of yours)

 

Grounding that wire should light the bulb, if not...the bulb is burnt out or there is a break in that cicuit.

It sounds like whoever fixed the plug mixed up the charge light wire and the sense wire, that would explain the high charging and the light not going out.

 

I would double check the connections at the alternator and make sure they are correct.

 

Also it would be good to check and make sure the bulb is working like gloyal said

Edited June 9, 201312 yr by mikaleda

Thank you both, I am going out to try these suggestions.

I will let you know, thanks.

I grounded the blk/wht wire, indicator charge light came on. After swapping the wires, the light still does not come and charging indicates 12.2v. Any suggestions? New alt, new pigtail, battery is charged.

It sounds like the battery warning light circuit is working okay and the trouble is with the alternator so I suggest you have it checked. You may have to swap those wires back the way they were. I'm not sure if the newer cars have a three wire design or two. If there are three wires then the ECU may control the regulation of the alternator. In the two wire designs one lead is for the voltage regulator to monitor the battery voltage so it ties to the battery. The other battery warning lead ties to the exciter field windings so that is why it is critcal that battery warning light functions, since it is in series with the circuit. The maximum DC charging voltage should be 15 volts.

I believe you are right. This 2010 legacy has the 2 wire circuit, and I believe the new alternator is not charging. I will have it tested and let you know.

It probably burned out the voltage regulator when it was charging at 15.5 volts. if you do need a new alt, double check the wiring and make sure they are going in the right places before you run it.

does anyone have a charging wiring diagram? it would be very helpful

After reading these posts again I think Mikaleda's thought about the wires being reversed might be correct. Since the regulator lead should be tied directly to the battery then tieing it to something else in series to that lead will cause the voltage at that point to be low. This will make the alternator output to go higher to try and charge the battery back to a normal level. In order to prove which lead should go where after the alternator is replaced check the voltage on each of the two pins of the alternator with the engine off, the alternator connector removed and the main output lead connected normally. Check each of the two pins using a voltmeter referenced to ground. I suspect the warning light lead should tie to the pin that has the lowest voltage reading on it. The other pin will tie to the battery sense lead.