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I need help with this one - 986 Forum - The Community for Porsche Boxster & Cayman Owners

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4 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCHI need help with this one - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Leading reported evidence

Check should be the alternator

Suggestion or failed attempt

No successful repair reported for this finding.

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Reported fixes
0
Unsuccessful attempts
1
Discussions
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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

So for future reference if you get a bunch of warning lights come on all at once your first check should be the alternator.

I need help with this one - 986 Forum - The Community for Porsche Boxster & Cayman Owners
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Leading evidence: 'Check should be the alternator' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check should be the 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.

Source reports, not a diagnosis or a success probability. Counts refer to discussions and can overlap.

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1 matching discussions · 4 captured posts examined · 0 partial discussions

Compare 4 other evidence results

Replace alt and battery together if one fails

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
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

Always change both alt and battery together if one fails.

I need help with this one - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Run off the alternator and the battery was caput

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
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 · Original poster

I rolled it to start and drove the 40 miles home but on arrival the battery was equally flat so its fair to assume I'd been running off the alternator and the battery was caput.

I need help with this one - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Run ok

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
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 · Original poster

The battery I though was kaput because it went flat without warning after a 40 mile drive and didn't charge after another 40 miles but the car run ok on the alternator was put on another Porsche I have and after standing for week with the alarm on started first time.

I need help with this one - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Run on a kaput battery

Suggestion or failed attempt

No successful repair reported for this finding.

0
Reported fixes
0
Unsuccessful attempts
1
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 · Original poster

The alternator was the original problem, not the alternator being the result of running on a kaput battery.

I need help with this one - 986 Forum - The Community for Porsche Boxster & Cayman Owners
Frequently discussed actions (5)

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

Check should be the 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

So for future reference if you get a bunch of warning lights come on all at once your first check should be the alternator.

I need help with this one - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Replace alt and battery together if one fails

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

Always change both alt and battery together if one fails.

I need help with this one - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Run off the alternator and the battery was caput

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

I rolled it to start and drove the 40 miles home but on arrival the battery was equally flat so its fair to assume I'd been running off the alternator and the battery was caput.

I need help with this one - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Run ok

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

The battery I though was kaput because it went flat without warning after a 40 mile drive and didn't charge after another 40 miles but the car run ok on the alternator was put on another Porsche I have and after standing for week with the alarm on started first time.

I need help with this one - 986 Forum - The Community for Porsche Boxster & Cayman Owners

Run on a kaput 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

The alternator was the original problem, not the alternator being the result of running on a kaput battery.

I need help with this one - 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.

4 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.

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

Outcome without a verified action link

New battery fitted and everything was back to normal.

No unique explicit quoted action; no causal link assigned

Generation: 20261027T075545Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

Misbehaving Boxster S Day 1; Drove 40 miles, parked for 2 hours (everything switched off) and the battery was too flat to start the car when I returned. I rolled it to start and drove the 40 miles home but on arrival the battery was equally flat so its fair to assume I'd been running off the alternator and the battery was caput. New battery fitted and everything was back to normal. Day 2; Brake pad warning light came on. Checked and found the front were a bit low but rears had life left in them. I ordered pads. Day 3; ABS warning light came on quickly followed by the battery / charging light. Fitted the new front pads thinking the pad warning light would go out and hoping the ABS was linked to this circuit . . no such luck everything stayed on. Day 5 and still trying to find the fault. I've had all ABS sensors disconnected and the light stays on. I've had all brake pads sensors disconected and the light stays on. The battery went flat again so I can safely assume it isn't charging. The battery I removed was fitted to a 944S2 cab' I have and guess what it worked and stayed working so the battery wasn't the fault with the Boxster. I can't think of how these circuits are related but the chances of all theses faults happening in such quick scuccession is about zero. Any advice or ideas would be appreciated

POST 2Original post

Alternator 110% Always change both alt and battery together if one fails. By driving on just your alt with a dead battery for that far you toasted it. Like I said 110% sure it will solve all you problems, most cars have the abs light plus others start to come on when the alt is toast.

POST 3 / ORIGINAL POSTEROriginal post

Thanks Matt, I did trace that and overhalled the alternator. That sorted the charge light but did nothing for the ABS warning light. There's no fault with the brake light circuit which is driectly linked to the ABS but I'm not sure if there is a fuse for the ABS system. Some kind Porsche mech took the fuse box plan last time it was with them and I hadn't noticed until now. Any idea if there is a fuse before I start pulling sensors out?

POST 4 / ORIGINAL POSTEROriginal post

Hi Matt (and others) you'll need to read from the begining to make sense of it Just for interest in case you get the same problem at some point. The battery I though was kaput because it went flat without warning after a 40 mile drive and didn't charge after another 40 miles but the car run ok on the alternator was put on another Porsche I have and after standing for week with the alarm on started first time. The original fault wasn't the battery. The alternator was the original problem, not the alternator being the result of running on a kaput battery. The regulator had given up but the windings were good. Incidentally the pulley wasn't free wheeling as it should so that was £50 plus the regulator and general overhaull £150 in total. Much cheaper than a new unit. With the overhauled alternator fitted all warning lights went out except the ABS light so I went through that manually unhooking each socket and unhooking the ABS pump from its power supply. none of that put the light out so I cleaned up and refitted all 4 sockets & plugs until I came to the last one at the left rear. That was the fault and unrelated to the orginal charge, brake pad, and other lights coming on (all of whcih were caused by the alternator) In UK the left wheels pick up more dirt then the right because thets the side in gutter all day. So for future reference if you get a bunch of warning lights come on all at once your first check should be the alternator.

This is a source reference. Confirm exact model applicability in the original material.