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No heat or cold from HVAC

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

THIS DISCUSSION / SOURCE-DERIVED OVERVIEW

Discussion summary

YOUR RESEARCHNo heat or cold from HVAC

Leading reported evidence

Fill with hot coolant

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
The heater core is always filled with hot coolant, so the flap/door controls the air passing over the heater core.
Original post Read captured discussion
No heat or cold from HVAC

Read full discussion summary

Leading evidence: 'Fill with hot coolant' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Fill with hot coolant' (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

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Repair anything inside the hvac box you have

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
And unfortunately, to check or repair anything inside the HVAC box you have to remove the entire dashboard.
Original post Read captured discussion
No heat or cold from HVAC

Replace mix between heat and cooling

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
There are diverter flaps/doors inside the HVAC box that move to allow outside air in, and change the mix between heat and cooling.
Original post Read captured discussion
No heat or cold from HVAC

Frequently discussed actions (3)

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

Fill with hot coolant

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
The heater core is always filled with hot coolant, so the flap/door controls the air passing over the heater core.
Original post Read captured discussion
No heat or cold from HVAC

Repair anything inside the hvac box you have

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 unfortunately, to check or repair anything inside the HVAC box you have to remove the entire dashboard.
Original post Read captured discussion
No heat or cold from HVAC

Replace mix between heat and cooling

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
There are diverter flaps/doors inside the HVAC box that move to allow outside air in, and change the mix between heat and cooling.
Original post Read captured discussion
No heat or cold from HVAC

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.

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: 20261026T063944Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

It sat for 7 days. AC worked fine before. This morning AC seemed warm. Switched to HI and heat wasn't really hot. Switched back to LO and got cooler for a bit but didn't seem to stay cold. I haven't put a IR thermometer to it yet, this was just by hand. Is there a specific diverter that I should be looking at? 2004 C4S

POST 2Original post

A simple thing to do is engage the AC, make sure it is set to LO, then open the engine lid and see if the AC compressor is engaged (the electrical magnetic clutch) and turning at the same speed as the other pulleys. If it is not, then it could be low freon or an electrical fuse or relay.

POST 3 / ORIGINAL POSTEROriginal post

The clutch engages as it should. Is there an air deflector that I should look at?

POST 4Original post

I'm not sure what you mean by "air deflector". There are diverter flaps/doors inside the HVAC box that move to allow outside air in, and change the mix between heat and cooling. The main one is the flap/door that moves to block air from the heater core. The heater core is always filled with hot coolant, so the flap/door controls the air passing over the heater core. There are a bunch of HVAC box external electrical switches with levers that control the flaps. I've never really seen a good write up of what does what on the HVAC box. And unfortunately, to check or repair anything inside the HVAC box you have to remove the entire dashboard. See diagram here http://www.autoatlanta.com/porsche-p...section=813-05

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