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quick question about alternator - 986 Forum - The Community for Porsche Boxster & Cayman Owners

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YOUR RESEARCHquick question about alternator - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Leading reported evidence

Check alternator

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Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

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Performed · outcome unconfirmed · Original poster

Well checked the alternator with multi meter.

quick question about alternator - 986 Forum - The Community for Porsche Boxster & Cayman Owners
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Leading evidence: 'Check alternator' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check alternator' (1 discussions). For that action, 0 discussions report a resolution and 0 report an unsuccessful attempt. No action has an explicit, attributable resolution report under the current rules. These are forum reports and suggestions, not a confirmed diagnosis.

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Replace alternator tonight

Performed · outcome unconfirmed

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Reported fixes
0
Unsuccessful attempts
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Discussions
Read evidence and context

Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that performed work without a confirmed outcome
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Performed · outcome unconfirmed

I had 12.1 when I just changed my Alternator tonight.

quick question about alternator - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Check next

Suggestion or failed attempt

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Read evidence and context

Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion · Original poster

Could there be a regulator or solenoid that I should check next?

quick question about alternator - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Disconnect battery

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Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion · Original poster

Should my car continue to run if I disconnect the battery.

quick question about alternator - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Suggestion

I don't believe disconnecting the battery with the car running is a good idea.

quick question about alternator - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Disconnect battery leads

Suggestion or failed attempt

No successful repair reported for this finding.

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Discussions
Read evidence and context

Explicit resolution reports before identified causes, performed actions and suggestions. Within each level, matching component labels precede direct query mentions and inherited thread context; successful versus unsuccessful discussion counts, owner confirmations and independent discussion support determine order. This is not a probability of success.

Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

And when (if) you charge your battery with an external charger, you need to disconnect the battery leads from the car & leave it being charged for at least 12 hours......

quick question about alternator - 986 Forum - The Community for Porsche Boxster & Cayman Owners
Frequently discussed actions (8)

These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.

Check alternator

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that performed work without a confirmed outcome
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Performed · outcome unconfirmed · Original poster

Well checked the alternator with multi meter.

quick question about alternator - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Check next

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion · Original poster

Could there be a regulator or solenoid that I should check next?

quick question about alternator - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Disconnect battery

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion · Original poster

Should my car continue to run if I disconnect the battery.

quick question about alternator - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Suggestion

I don't believe disconnecting the battery with the car running is a good idea.

quick question about alternator - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Disconnect battery leads

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

And when (if) you charge your battery with an external charger, you need to disconnect the battery leads from the car & leave it being charged for at least 12 hours......

quick question about alternator - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Replace alternator

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion · Original poster

How hard is it to replace the alternator?

quick question about alternator - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Replace alternator tonight

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
Discussions
Read evidence and context
Discussions that performed work without a confirmed outcome
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Performed · outcome unconfirmed

I had 12.1 when I just changed my Alternator tonight.

quick question about alternator - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Test alternator in the old days

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Suggestion · Original poster

This is a quick way I use to test the alternator in the old days.

quick question about alternator - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Test alternator output

No successful repair reported for this finding.

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Reported fixes
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Discussions
Read evidence and context
Discussions that contain suggestions
1

0 original-poster resolution reports. Counts can overlap; they are not unique people or a success rate.

0 discussions have direct query context; 0 report a fix in that context. Other evidence may inherit the discussion’s subject.

Suggestion

Did you test your alternator output with maximum load?

quick question about alternator - 986 Forum - The Community for Porsche Boxster & Cayman Owners
Coverage and how to read this overview

Counts describe captured discussions, not unique people or a diagnosis. Author identities are not reliably stored. Exact duplicate evidence is counted once across matching discussions; one discussion counts at most once per action/state. Multiple repairs reported together remain a combination. Suggestions and failed attempts do not establish a fix. Matches cover whole discussions and can include related faults, model variants and incomplete threads.

9 eligible posts · 0 unverified posts · 1 discussions match the subject in their title or opening post.

  • 986Forum: 1 discussions

0 evidence records excluded for query context · 0 excluded by outcome qualification · 0 adjusted by outcome qualification.

0 acknowledgements have no verified action link; they do not establish a repair result.

Generation: 20261026T152433Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

I have been having problems keeping my battery charged. I have got a new battery from Autozone and the problem still returns. If I let the car sit for a day or so, the battery is very low. I left the lights on tonight when I got pulled over, and I had to get a jump from DPS after only 10 mins of sitting. I got a warning for no front plate if anyone is wondering. Anyway, my question is..... Should my car continue to run if I disconnect the battery. This is a quick way I use to test the alternator in the old days. The thought is that the car only needs the battery to start. The alternator should put out enough juice to run. With the car started, battery diconnected, it idles rough....... If I turn on the lights the car dies. I dont have a multimeter. What should the alternator be putting out at idle? Thanks, James

POST 2Original post

I had 12.1 when I just changed my Alternator tonight. Car started up fine. Then I had about 13.3 or so. You should look for atleast 13 volts to be going into the battery for it to be charging.

POST 3Original post

I don't believe disconnecting the battery with the car running is a good idea. I think I read somewhere that it will immediately kill the alternator by taking out a diode or two. It sounds as if your alternator may be the problem.

POST 4 / ORIGINAL POSTEROriginal post

Yea, I think it is the alternator as well. This is my second one. It is 4 yrs old. I am going to get a multimeter today and see what the output is. I am planning on going with a 4 inch underdrive pulley in about a week, and if the alternator is low now, it will be worse then. How hard is it to replace the alternator? I have done it on cars and trucks many times, but this car is so cramped it may be different.

POST 5Original post

With the car started, battery diconnected, it idles rough....... If the alternator wasn't dead before, it is now. The battery acts as a voltage buffer for the electronic system; you remove the buffer and the spikes kill the system.

POST 6 / ORIGINAL POSTEROriginal post

Well checked the alternator with multi meter. It seems to be fine. output is 13.8V with 45 amp. I guess it is the battery...Its is only 6 mo. old and it is the third battery I replaced. Could there be a regulator or solenoid that I should check next?

POST 7Original post

Have you tried charging the battery on a charger? Don't assume that just driving around is getting you to full charge. When a battery is fully charged, after you let it sit for a few hours to dissapate the surface charge, you should read a voltage of 12.75 V. Anything lower than that (e.g. even 12.6 V) means the battery isn't fully charged, If your system voltage is 13.8 V, your alternator is working. If you start with a fully charged battery and it's not staying at 12.75 V after you drive the car, the battery needs replacement.

POST 8Original post

Did you test your alternator output with maximum load? Put your headlights on, heater fan on high, stereo on, and anything else you have that pulls juice, then see what the output is. With this load it may no longer be in the normal range, indicating an alternator problem.

POST 9Original post

And when (if) you charge your battery with an external charger, you need to disconnect the battery leads from the car & leave it being charged for at least 12 hours...... Then do your voltage check.

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