9 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHManual engine compartment fan switch?
Reported or suspected cause
relay
Reported cause
No successful repair reported for this finding.
1
Identified cause
0
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 report identifying 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.
Reported cause
Fault traced to the relay under the carpet ‘parcel shelf’ in the rear.
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, I checked the fan fuse, it was ok, check the fan itself - two wires connected to the battery - it works, so my suspicion is on the relay, but then I was thinking, can I make a manual switch for the fan?
Leading evidence: 'relay' (1 discussions report identifying this cause; no attributable repair resolution). Across 1 matching discussions, the most frequently mentioned possible cause is 'relay' (1 discussions; 1 report identifying it and 0 suggest it). The most frequently discussed action is 'Check fan fuse' (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.
Test fan itself by unplugging and putting 12v across it
Performed · outcome unconfirmed
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 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
Tested the fan itself by unplugging and putting 12v across it.
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, I checked the fan fuse, it was ok, check the fan itself - two wires connected to the battery - it works, so my suspicion is on the relay, but then I was thinking, can I make a manual switch for the fan?
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, I checked the fan fuse, it was ok, check the fan itself - two wires connected to the battery - it works, so my suspicion is on the relay, but then I was thinking, can I make a manual switch for the fan?
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.
These are separate views of the same evidence. Frequency alone does not establish a fix, and these counts must not be added together.
Check fan fuse
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, I checked the fan fuse, it was ok, check the fan itself - two wires connected to the battery - it works, so my suspicion is on the relay, but then I was thinking, can I make a manual switch for the fan?
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, I checked the fan fuse, it was ok, check the fan itself - two wires connected to the battery - it works, so my suspicion is on the relay, but then I was thinking, can I make a manual switch for the fan?
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.
911uk: 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: 20261026T172408Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources
I had a nice 50 km drive on Istrian roads, and I noticed that the engine compartment fan is not working, then I got a flashy red light on the temperature gauge, even though temperature was slightly over 80C.
So, I checked the fan fuse, it was ok, check the fan itself - two wires connected to the battery - it works, so my suspicion is on the relay, but then I was thinking, can I make a manual switch for the fan?
Has someone done it?
I am thinking on simple solution, getting the 12V on the fan, with separate switch, and then turn it on and off when I want, and still leave the automatic system with the new relay.
The engine fan comes on very late based on engine compartment temperature. I don't remember ever having mine come on, though I have tested it with Durametric and it definitely works.
I would suggest you get your codes read as the temp light should not flash at 80-90 degrees.
The engine fan is only there to dissipate heat when you shut down the engine after a run and will really only come on if it's a very hot day and you've been spanking the car hard. It has nothing to do with the coolant temp.
Thank you, I got the reader, and it was a suspicion on the relay. It is not a complicated fix, and not expensive one, and I reckon this one is 26 years old, so I will buy a new one.
There might not be anything wrong with it. There's a temp sensor in the engine bay that activates the fan and that will only switch the fan on if it gets hot. That fan does not cool the coolant.
You're flashing red light is more of an issue, Either that is faulty or your temp display is faulty.
I had the dash warning about the compartment fan. Tested the fan itself by unplugging and putting 12v across it.
Fault traced to the relay under the carpet ‘parcel shelf’ in the rear. Relay had fallen out!!
IIRC the sensor is clipped to the inlet plenum on the right cyl bank.
Have a read of this....
Thread 'Huge favour needed....need to see wiring on the back of relays behind the seats of 997.1 coupe...'
20 Jun 2025
As the title says really, I have an issue with my engine compartment fan not coming on, even if I tell it to in Durametric.
Tested the fan sending it 12v dc direct, and it works fine.
After spending a couple of days looking at wiring diagrams and testing all the bits associated with the fan, they are all working fine.
After looking at the relay board behind the rear seats, under the panel, the wiring just doesn't look right to me. There is meant to be 5 wires to the first relay (position 8) and there is only 4, also, it seems that the wiring is going to the wrong pins too.
Relay 2 also...
gizlaroc
Replies: 27
Forum:
Porsche 911 997 (2004-2012)
