1991 volvo 240 wagon

so my battery died while on the road. i was stuck so i walked to a parts store up the street and bought a new battery to get myself home. when i got home i tested the voltage on the alternator and it read 11.85v or so. i removed it and took it to kragen auto parts because it has a lifetime warranty. they bench tested it and it failed. they replaced the alternator and i installed it. there are only 3 wires; positive (red) ground to body (blue) and a spade clip that is red. when i hooked everything up i went to start it and the battery light was on when the key was out and the car was off. i started it and read the voltage on the alternator and it was still about 11.85v or so on the new alternator. i took it back to the parts store thinking that the new one was bad. they bench tested it and it passed. any ideas what's wrong? any help is greatly appreciated. thanks.

 

"...the battery light was on when the key was out and the car was off."

Just the BATT light? Or the whole Christmas tree?

 

You may have a bad instrument panel circuit board which would affect the alternator (if the Alternator light is faulty). The light being ON when ignition is OFF is odd but the bad board may cause all kinds of weirdness. I am dealing with a 745 and a 945 with this very ptoblem--the 240 is similar...

 

Do this: run a wire between the battery + terminal and the spade connector in the back of the alternator with a bulb wired somewhere in between--bulb should light up. Start the car and the bulb should go off just like the ALTERNATOR light on the dash. Check to see if the alternator is charging at that point.