95 Legacy - Not Charging, Battery Light on when Key is off?

[lmdew]

A fellow in town has a 95 Legacy, Auto.

 

I gave him an Alt to fix his charging problem, it was used but good as far as I know.

 

Gave him another used one, same thing.

 

He stopped over today, good battery voltage 13 volts.

 

I changed a the alt again, no luck.  When the car is started battery voltage goes down to 12.5 volts and 12.3 with the light on.

 

Fuses look good, connections clean.

 

Then I noticed the battery light on the dash is on when the key is off.  I have never seen this before.

 

Help!

 

Thanks, Larry

[idosubaru]

Does the brake light go out if you disconnect the alternator completely (car off, key out)?

 

No custom stuff like security, stereo?

[lmdew]

Yes t he Battery icon goes away with the Alt disconnected.

Trying another one!

 

No security stuff.

 

Thanks,

Larry

[Fairtax4me]

I might suspect a short somewhere in the wire for the light. Possibly shorted to the second wire in that harness?

 

Make sure both wires at the alt have 12v reaching the plug.

Edited November 22, 2016 by Fairtax4me

[matt167]

Alt light gets power from 2 sources. The alternator and one other. So its grounded when lit. Something tells me the circuit sub used on that is constant, and non functional

[lmdew]

Bad Alt causing the battery light.

Bad Main Ground wire, burnt contacts at the engine ground point.

 

Fixed, Happy Subaru Owner.

 

Thanks Gary!

 

Larry

[idosubaru]

Great good job beast. Tricky one. I was going to ask if it's possible that bad wiring could ruin the alternator?

 

For instance can a short fry the internal voltage regulator the moment a new alt is installed.