Carrera 3.2... How can I test my alternator?

[99 Boxster]

My battery won't charge... I have had to push start it twice. I had the battery tested at Autozone and they said it was fine.

1. How can I test the alternator? Isn't there supposed to be a light when the alternator breaks?
2. Where can I find an alternator and how much do they usually cost?

[Bob Kontak]

Buy a decent ($50-$75) multi meter and test the DC voltage off the battery when the car is running using the DC scale. Watch a youtube video on how to use them. You voltage should be over 13 volts if the battery is fully charged and the voltage regulator and alternator are working. If you have a worn down battery (from cranking) the voltage should be closer, and perhaps over 14V.

Alternators cost under $200 if purchased from a local parts store. Pelican will be a wee bit more. Pelican also sells some spiffy upgraded units that spew out lots of power. A couple of hundred more but perhaps worth it for your piece of mind.

Check your voltage first then we can focus on why the charging light is not red.

[Joe Bob]

The light comes on when you turn on the ignition. It goes out when your engine is running and turning fast enough. The light is part of the charging system. IF it is burned out it will nt charge.

Check for proper bulb function. If it is burned out replace it.

A VM on the battery should read 12.5v+.

Idle 13.0+
2500 rpms, 13.5-14.0

Over 14 you may have issues with the battery and other components.

[99 Boxster]

Originally Posted by Joe Bob

The light comes on when you turn on the ignition. It goes out when your engine is running and turning fast enough. The light is part of the charging system. IF it is burned out it will nt charge.

Where can I find this light?

[Joe Bob]

They are in the gauges. What year is your 911? You don't give me a lot to go on.....

Typically there are two lights. Mine for example are both red. One is oil and the other is the alternator and they are in the gauge second from the left. They come on and go ut after the engine running. It's a self test.

They are nicknamed "Idiot Lights".....

[DRACO A5OG]

Originally Posted by Joe Bob

The light comes on when you turn on the ignition. It goes out when your engine is running and turning fast enough. The light is part of the charging system. IF it is burned out it will nt charge.

Check for proper bulb function. If it is burned out replace it.

A VM on the battery should read 12.5v+.

Idle 13.0+
2500 rpms, 13.5-14.0

Over 14 you may have issues with the battery and other components.

+1

also check the connectors, even a tiny crack will give you grief

[99 Boxster]

I just got back from Autozone and they tested my alternator with some little box and said it's fine. The only other thing I could think of, is this huge amp and sound system connected directly to the battery... I'm no audio technician, but that's not how it's supposed to be done, is it?

[kidrock]

Let's start at the beginning: Why do you believe that your battery is not charging? Please describe the symptoms you are having.

If your car is not turning over at the starter, that is not always indicative of a bad battery or alternator.

[strikee]

Best three bucks I spent on ebay. Mine now lives permanently in the cigarette lighter socket. At idle reads late 12v, running its up in the 14v range. This confirms to me the alternator is running, my fan belt is in tact and im a happy camper. The lack of a volt meter guage as standard amazes me.

12V 24V LED Display Digital Auto CAR Volt Meter Monitor Vehicle Voltage Gauge | eBay

[m110]

Get one of these, will give a good reading of voltage as you drive. >14.3 beware

Equus 3721 Battery and Charging System Monitor : Amazon.com : Automotive

[pavegeno]

+1 on the Equus

I have it permanently installed under the dash and it rocks. Piece of mind.

[Bob Kontak]

Originally Posted by 99 Boxster

sound system connected directly to the battery... I'm no audio technician, but that's not how it's supposed to be done, is it?

Believe so with an in-line fuse.

You know, you could always try and unhook the stereo wires from the battery and see what happens.

How much work have you done to get to the bottom of this aside from a few trips to Autozone?

[ivangene]

battery age could be your problem - plain and simple, its worn out (maybe)

[rinverso]

Originally Posted by DRACO A5OG

+1

also check the connectors, even a tiny crack will give you grief

i'm having the same issue. my 86 3.2 targa charging light doesn't light at all. this would cause the battery not to charge from the alternator? when you mention the connectors, are you referring to the connectors to the bulb? do i need to pull the entire gauge to inspect?

[dshepp806]

As mentioned, the bulb is PART of the charging circuit.

Best!

Doyle

[rinverso]

Originally Posted by dshepp806

As mentioned, the bulb is PART of the charging circuit.

Best!

Doyle

do you pull the gauge to get at the bulb?

[RDM]

Originally Posted by rinverso

do you pull the gauge to get at the bulb?

Yes. The gauge should pull directly out of the dash- it's a friction fit with its rubber gasket. Remove steering wheel first for best success.

[rinverso]

Originally Posted by RDM

Yes. The gauge should pull directly out of the dash- it's a friction fit with its rubber gasket. Remove steering wheel first for best success.

vielen danke!

[rinverso]

a big thank you to joe bob and jim "draco". i was almost about to pull the alternator. and here it was just corrosion on the spade connectors to the alternator light socket. amazing that would cause my battery from charging. saved me $400 and 6 hours labor. this is why i'm on this awesome forum.
thanks again

[millarg]

Originally Posted by strikee

Best three bucks I spent on ebay. Mine now lives permanently in the cigarette lighter socket. At idle reads late 12v, running its up in the 14v range. This confirms to me the alternator is running, my fan belt is in tact and im a happy camper. The lack of a volt meter guage as standard amazes me.

12V 24V LED Display Digital Auto CAR Volt Meter Monitor Vehicle Voltage Gauge | eBay

Have one of these in the Porsche and my truck, live permanently in the cigarette socket, well worth $3.