Hey guys I just joined rennlist about 10 mins ago although I've had my car for 2+ years. It's an 87 944S. I decided it was time to get on here because after 2 years of blood sweat and tears shes finally starting to be where I want her. I've had both CVs fail, clutch master and slave cylinders, cooling fans go, exhaust stud broke off, and finally the transmission self-destructed. You name it, its happened.

Now she's reaching the peak of her life:
Transmission: 951 with external oil cooler
Clutch: Clutchmasters
Suspension: Front adjustable konis with 968 springs, Rear bilsteins + 18mm rear sway bar
Typical power upgrades: autothority chip, bursch exhaust, custom K&N cold air intake
While i was putting in the transmission I did a full tune up (all filters, plugs, wires, cap and rotor)
She's got new seats, 944 Turbo rims (16x7, and 16x8) with new tires on the way, head's been rebuilt, belts, rollers, seals, etc.

HOWEVER....I believe I'm on the verge of an alternator problem. Car cranks and starts no problem, powerful, but after it has been running for a while voltage reads juustt over 12, and it used to run around 14. Any advice on what to look for/check. The car has a custom ground kit, so I am going to go over and check all the grounds, but if anyone can think of anyhting or has experienced this before any advice is greatly appreciated. Thanks!

 

Easy things (besides the grounds) would be to check the voltage regulator. Clark's has a procedure about checking that, there should be a certain amount left on the brushes.

I had a similar problem (my light harness is powered by the alt and suddenly stopped working). I took a voltmeter to my battery and it didn't appear to be charging the battery. Replaced alternator (thanks, schwank!) and it was charging again. IIRC, I got a reading of 12 when it wasn't working and a 14 when it was. Took the readings at the battery.

 

if you're using the voltmeter in the cluster without cross checking with a decent dvm, you might have nothing to worry about.

if dvm shows low voltage, take it to napa, carquest, checker for a quick check.

if it shows a problem, it could be alternator, diodes, voltage regulator, grounds, wiring harness, etc.......

87951

 

Your car reads sweet. Probably the voltage regulator. An alternator is a stupid thing and either works or doesn't.