Alternator overcharging

[Pfitz911]

Hi gents
Read a few posts on this but seeking further clarification
My alternator wasnt charging several weeks ago, so I took it out and to my porsche guy. They promptly sent it off to some guy and told me the regulator was stuffed...no worries, so I had it fixed and fitted it back in.
I took pics so see where the wires went (3) and hooked it back up and fitted it. Getting the fan belt to tighten was a ***** tho...had to remove some shims (would this be a problem?)
The other thing I noticed was that the rubber seal on on of the wires was perished and didnt go back on, so I left it bare...again, could this be a problem??
So Im driving to work and theres this acid smell which I now know is overcharging the battery. I heard a hissing sound and quickly pulled over, to find smoke/steam coming out of the battery.
So what went wrong? is it possible that I installed the wrong wires to the right terminals of the alternator?? Is it a bad regulator??
Its currently 5km from my house cooling down. I have disengaged the battery terminals.
Is the battery now stuffed or can I reuse it?
Lucky I LOOOVE these cars.
Thoughts welcome

[CCM911]

I just went through the identical issue. I replaced my Voltage Regulator, and then took the car for a 200 mile trip. Yep. I also smelled boilg battery!

I spoke to my tech, and he said he has seen this before. Looks like you'll be buying a new alternator, or having your current one rebuilt.

Not the end of the world. But I am sure you are just as annoyed as I was about wasting $80 on a new Voltage Regulator.

[Jesse16]

And yes your battery could be stuffed. (interesting word, like it) At least mine was when the VR failed and choked me on Acid fumes many years back. Lucky it was under warranty and I kept my mouth shut. Just shrug and let them test and replace.

[DRACO A5OG]

I would also have the battery tested to insure a cell or two or more was not damaged. Visually make sure it is not swollen.

Wow 5K from home, where are you maybe a pelican can lend a hand?

[Jesse16]

And just FYI, my battery did continue to work well enough so I drove it home with the new VR and had my local parts store where I had purchased it test and replace.

[Franks89-911]

Just my thoughts here, the people who actually know something I'm sure will promptly correct me if I'm off. You didn't say what year your pcar is but your alternator looks older than mine (89).

1. Your battery is toast. If it's hissing and gassing, it's done. It may well have exploded in the frunk so you may have some acid damage up there too. Time to get out the baking soda and water to neutralize the acid. Invest in an Absorbed Glass Mat (AGM) battery for the future.

2. Before you just drop a new battery in there and try to drive again, you need to see how much voltage the repaired alternator is putting out. Your symptom sounds like an overcharge, that's what batteries do when they get too much lifeblood through them. I'd have it towed back to the mechanic and I wouldn't drive it again until this problem is corrected. The voltage regulator may not be working correctly.

3. For the future invest in a voltage monitor. I have this after I had my alt rebuilt, plugs right into the cigarette lighter. http://i.walmartimages.com/i/p/00/04/21/73/03/0004217303721_500X500.jpg

4. That hanging wire pointing toward us in the pic has me worried. Is that the ground wire? I don't see a connector on its end in your pic, just a bare piece of copper. Did the connector break off? If you have a wire that's unconnected that's bad, every wire should go somewhere. I know, I'm Captain Obvious. :-) I believe on most alternators there are 3 connection points. I only see 2 in your pic. I'd buy a new rubber piece too.

5. This is a good read. Porsche 911 Alternator Troubleshooting and Replacement | 911 (1965-89) - 930 Turbo (1975-89) | Pelican Parts DIY Maintenance Article

6. Re: the shims, hopefully you saw how many shims were on each side of the pulley and replaced them as they were first, before adjusting them for belt tension. Should always have 6, tightness of the belt is adjusted by moving them from one side of the pulley to the other. If you had to put less than 6 back to make the belt not slip, then you have something else going on like a warped fan housing or an incorrect reinstall.

Good luck!
-Frank

[Pfitz911]

Thanks guys
Yes the connector broke off but I replaced with new one. Should I have just had my alternator replaced in the first place?
Frank, I will get busy with the baking soda
Got my car home last night, with wife following me. Car starts and drives really well, so Im wondering if the battery is OK?? Like you guys have said, maybe it isnt, so Im up for a new alt and bat.
Lucky I LOOOVE these cars
Dan

[Jdub]

I would replace the brown ground cable from the alt. to (typically) engine - it is inexpensive and a smart move as a "while you are in there." Also, be sure the ground strap from transmission to body is in good condition as well - at least the connections as it is a PITA to replace without a lift.

Reason I suggest this is a solid ground from both your alt. and battery will yield best testing results and it is cheap to do.

Last thought: If your existing alt. can be rebuilt do it - it will go in just as it came out with no fuss.

[Franks89-911]

Originally Posted by Pfitz911

Should I have just had my alternator replaced in the first place?

No, that costs $800+. A rebuild is much cheaper and accomplishes essentially the same result.

I would recommend you get a voltage meter to monitor how your alternator is doing, before driving again. Anything above 14.5v is cause for concern, but at least you could stop driving if the volts get too high before you turn your battery into your own personal Volcano Reproduction again. Normally I think the alternator should spit out between 13 and 14 volts for adequate charging. The more electricals used (a/c, lights, etc.), of course, the lower the voltage readout.

[gomezoneill]

Originally Posted by Franks89-911

No, that costs $800+. A rebuild is much cheaper and accomplishes essentially the same result.

I would recommend you get a voltage meter to monitor how your alternator is doing, before driving again. Anything above 14.5v is cause for concern, but at least you could stop driving if the volts get too high before you turn your battery into your own personal Volcano Reproduction again. Normally I think the alternator should spit out between 13 and 14 volts for adequate charging. The more electricals used (a/c, lights, etc.), of course, the lower the voltage readout.

I just bought a brand new (no core) Valeo from ebay 180 dollars. After installation works perfectly. Not 800 dollars. No disrespect intended just wanted to show you three's better deals out there.

[Franks89-911]

Originally Posted by gomezoneill

I just bought a brand new (no core) Valeo from ebay 180 dollars. After installation works perfectly. Not 800 dollars. No disrespect intended just wanted to show you three's better deals out there.

None taken. You got a deal, congrats; our host shows a new Valeo for me (89) at $590 and a new OEM Porsche at $916.

[Walt Fricke]

It is nice to have an old timey auto electric shop in town. My alternator stopped working part way through a race. I didn't notice that the voltage was 11.2 until after the checker, so I was OK. But out came the alternator and off to the shop. Guy said oh, you have a Porsche after a glance at it in my hand walking in. Couple of hours later he called and said it needed a new stator (the coil windings) and some diodes were toast, plus something was wrong with the slip rings. $280 to rebuild, but he had a rebuild on the shelf for the same price. Obvious deal since I need the car for next weekend two days away. Looked like new.

Everyone should have a voltmeter. Simplest is the kind you just plug into the cigarette lighter. The problem is that, at least up to some point, Euro cig lighters are fatter, so the socket is wider as well. You can shim a US plug in volt meter so it will stay put. If you happen to have some early Porsche connecting rod bushings, they can be shoved into the cig lighter, and a US size volt meter inserted. It is a really really tight fit - no chance of its working its way out. Maybe the WalMart volt meter fits you car tightly without the need for any modifications?

[rick-l]

Does the charge indicator light operate normally?

[Joe Bob]

Buy a volt meter as well, replace that worthless clock like I did. Westach made me a VM and head temp gauge.

[gomezoneill]

Originally Posted by Joe Bob

Buy a volt meter as well, replace that worthless clock like I did. Westach made me a VM and head temp gauge.

What size is it 3 or 4 inch? Did it fit in the opening for the clock with no problem? Can you post a photo?

[Joe Bob]

Probably 10 years ago, something like $120 USD. Best to call and inquire....

[Joe Bob]

[gomezoneill]

What's on the left side?

[Joe Bob]

Single cylinder head temp. VM on the right....sensor for the CHT is on #2 spark plug.

[Walt Fricke]

Rick points to a feature of the charge indicator red light in the instrument cluster (in the speedo? - easy to get mixed up what is where unless in the car). The proper sequence goes like this: turn key to on/run. Red light lights up. Start engine. Red light goes off.

So, if you are driving along and the red light comes on, you know either the charging system has packed up and quit, or the fan belt has come off. If the former, you can drive a while on battery alone (farther if not at night). But if the belt came off, you will shortly see the oil temps climb and you want to stop immediately, because there is no cooling air.

The tricky thing is to recognize the absence of the red light when first you turn the key on. I always think of it as Sherlock Holmes' dog that didn't bark in the night - not so easy to miss the implication of a warning light which isn't on during a preliminary (and typically almost millisecond) step in getting started.

The absence of this red light could also be due to the bulb burning out, just to confuse diagnosis a bit more.