Rennlist

Front fan keeps running - kills battery

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10 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis

THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCHFront fan keeps running - kills battery

Reported or suspected cause

high speed relay

Suggestion or failed attempt

No successful repair reported for this finding.

0
Identified cause: 1
Suspected cause: 0
Reported fixes

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 suspect a cause: 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.

Suspected cause
It's probably the high speed relay because of the higher current and contact wear involved.
Original post Read captured discussion
Front fan keeps running - kills battery

Frequently discussed work

Run after i shut the car off - even

No successful repair reported for this finding.

0
Reported fixes: 0
Unsuccessful attempts: 1
Discussions

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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 front fan on my '99 996 doesn't stop running after i shut the car off - even after short trips where it doesn't even heat up.
Original post Read captured discussion
Front fan keeps running - kills battery

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Leading evidence: 'high speed relay' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'high speed relay' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Run after i shut the car off - even' (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.

Read captured replies

1 matching discussions · 10 captured posts examined · 0 partial discussions

Compare 1 other evidence results

Run after i shut the car off - even

Suggestion or failed attempt

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 front fan on my '99 996 doesn't stop running after i shut the car off - even after short trips where it doesn't even heat up.
Original post Read captured discussion
Front fan keeps running - kills battery

Frequently discussed actions (1)

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

Run after i shut the car off - even

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 front fan on my '99 996 doesn't stop running after i shut the car off - even after short trips where it doesn't even heat up.
Original post Read captured discussion
Front fan keeps running - kills battery

Reported and suspected causes (1)

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

high speed relay

No successful repair reported for this finding.

0
Identified cause: 1
Suspected cause: 0
Reported fixes

Read evidence and context

Discussions that suspect a cause: 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.

Suspected cause
It's probably the high speed relay because of the higher current and contact wear involved.
Original post Read captured discussion
Front fan keeps running - kills battery

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.

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

Rennlist: 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: 20261027T165639Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

Subject pretty much says it all. The front fan on my '99 996 doesn't stop running after i shut the car off - even after short trips where it doesn't even heat up. Any thoughts? thx

POST 2Original post

Which fan (left or right)?

POST 3 / ORIGINAL POSTEROriginal post

Sounds like the passenger side at least, may be both it thats possible. Its pretty loud - sounds like the car is stil running

POST 4Original post

Relays 19 (low speed) and 20 (high speed) control the left side fan. Relays 21 (low speed) and 22 (high speed) control the right side fan. The relays are on relay support 1 in the left footwell. Pull one or both of the relays on each side until the fan stops. It's probably the high speed relay because of the higher current and contact wear involved. If that is the case, you can temporarily swap the low speed relay into that socket. Buy a new relay as soon as possible in either case.

POST 5Original post

For reference:

POST 6Original post

I don't know if this holds true for the 996's, but when the temperature sensor in the radiator failed on my old 944, its failsafe mode was to turn the fans on to avoid overheating.

POST 7 / ORIGINAL POSTEROriginal post

Relays 19 and 22 are there, but there are just holes in the 20 and 21 spots...

POST 8 / ORIGINAL POSTEROriginal post

Scratch that last comment.. seems the last row of relays is covered up. they're all there...

POST 9Original post

Quotes source post: 4511236

The fans are controlled by the DME here. However, if the fans on both sides are running when they shouldn't be, one of the sensors feeding the DME would be more likely to cause the problem.

POST 10Original post

Quotes source post: 4511266

Yes, there is a cover there to protect those components from your left foot.

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