so the clutch finally works, got it all back together this afternoon, drive home went without a problem.

i pull in and park the car and come back 10 minutes later, start her up and the alternator light stays on ...


rev her up, no change. turn her off and back on, same thing.
i checked all the fuses, rotated them, no change.



now effin what? alternator on a 3.6 is internal. how do i check on it ???
Andy

Andy,
You could start by checking the battery voltage to see if the charging system is exhibiting a problem.

this thread may help. the last few postings are the applicable ones.

http://www.dorkiphus.net/porsche/showthread.php?t=7536

sounds like the exact same thing.

Did you reconnect your ground cable? Just a random thought....

I'm inclined to think it has something to do with that new gauge, but I can't say what.

nope. see, it worked *fine* all the way home. if it was missing an external resistor or diode or whatever, i would have had that problem from the beginning.

i never touched the alternator. lights was off during my drive home.

it wasn't until i restarted the car, that it stayed on.
Andy

yes, ground strap attached ...

i took the old gauge with me. thank god i didn't hack into the harness, switching them out will be easy ...
Andy

I debated even posting that because I knew you would say that. But I just gots a feeling. When it's all over we'll see who's right and who's not.

Andy, it looks like you just installed new gauges. Yes? The alternator light MUST work since that circuit is what excites the alternator. So if the alternator light is not making a circuit, or the bulb is burnt out or not hooked up, that is your problem.

Good luck.....

yes. i know. like i said, the light STAYS on. doesn't go out. meaning, the bulb works ...

see, lighty worky ...




Andy

You did check your belt(s)?

Did you check the battery voltage running and off to see if there is a difference?

Another blury pic by the artist known as "SirAndy"....

belt(s) are fine ...



hey, i've got a reputation to uphold ...



here are the numbers, across the battery terminals:

• 12.61 V - ignition off
• 12.38 V - ignition on
• 12.06 V - idle
• 12.08 V - idle with gauge bulb disconnected, just for the giggles ...

clearly, it's *not* charging ...
Andy

I don't remember, is the stock diode hooked up to anything?

yes, stock diode is hooked up, but it's not for the alternator circuit. it's for the brake circuit.
it's used because the brake warning light has multiple functions (parking brake, master cylinder, seatbelt interlock and emergency flasher) ...

Andy

PS: to clarify, there's a diode in the alternator circuit on early cars, but i have a '74 main harness ...

Can, or did, you check the voltage regulator?

i wouldn't know how, it's all internal ...
Andy

alright, i need some strong coffee. i'm gonna drive her up to starbucks (about a mile from my house) and see what happens ...

got my AAA card with me ...
Andy

My internally switched alternator has but one wire connected to it.

It is tickled by low voltage from the thick wire coming from the battery.

Does yours use 1 thick wire or are there 2 or more wires?

What model and year is your engine?

i'll have to take the shroud off the motor to get a look.
there's no easy access to the alternator.

'95 993 3.6L motor ...
Andy

PS: leaving for starbucks, be back in a minute ...

Uh oh, it's been 30 minutes.

yeah, yeah ...


now, riddle me this:

after i got to starbucks and gulped down a double shotted espresso, i walk back to the car and fired her up.
light stays on, like before. parking lot is empty, so i give it a "spirited" takeoff.

and the damm light goes OUT !@*!!

so i pull over and put the multimeter to the terminals:

• 12.95 V at idle
• 14.04 V at 3k rpm


now it's working again ?!?


i suspect i either have a lose connection somewhere or the voltage regulator is on it's way out the door ...
Andy

That's one of those jobs I would pull the motor for....... Like the clutch.....

I seem to recall that a bad battery might cause this....

hmmmmm, it's 4 years old or so ...

maybe i should swing by flaps and get a new one ...
Andy

In the interest of helping someone else out, I will admit my brain lapse with my -4's charging system.

After going through two new Optima redtops and swapping my OE alternator for a new one(which sucked) It took me a solid day of lookin and head scratching till I plugged the alternator lead back into the relay board. and Low and Behold she lived.
I feel much better with that off my chest by the way.

Andy,
Before I dug in and removed anything I would just do some manipulation of the harness in the engine bay and any other related areas. Clearly its possible theres a skew some where that may show up. I would do it with the engine running so you can see any changes on the fly. Maybe have someone with there eyes on the dash or a dvom. I don't see hammering the throttle shaking loose an internal alternator problem but surely a wiring issue.. would be effected by vibration and engine twist.