Battery Won't charge in 87 Carrera with 97 993 motor

[p7guru]

Hey guys,

A few weeks back I noticed my car was taking a bit more to start from cold. Then A few days ago it wouldn't start at all (dead). I jumped it off, drove it around for about 3 miles. Tried to restart it and nothing, like the car hadn't charged it at all. Repeated the process tonight and drove around for about 25 min. Same thing.

What might this be? Where to begin?

[timmy2]

Possibly Alternator not charging due to internal wear or regulator failure. Or Battery is old and failing internally. Need to put a full charge on the battery overnight and test for voltage levels before starting, running at idle and at 3k rpm to begin to diagnose.

[theiceman]

Get a multimeter and let's get started

[john walker's workshop]

it works the same as any other year alternator. B+ to the starter solenoid 12V post, D- to ground, preferably a large gauge wire to the engine case, and the 61 terminal to the dash warning light, which has to light up with the key on, or it won't start charging. good clean and tight ground straps from trans to body and battery to body. attach a voltmeter to the battery and see if you have 13.5 to 14V @ 2500. may just need an alternator.