16 captured repliesDiscussion pagination complete · Source accounts, not a confirmed diagnosis
THIS DISCUSSION / SOURCE-DERIVED OVERVIEW
Discussion summary
YOUR RESEARCHAir conditioner problems
Leading reported evidence
Check related fuses all good
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
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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.
Leading evidence: 'Check related fuses all good' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, the most frequently mentioned possible cause is 'ignition switch - hope' (1 discussions; 0 report identifying it and 1 suggest it). The most frequently discussed action is 'Adjust output buttons' (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.
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 · Original poster
While I was at it I inspected for rodent activity…nothing.
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.
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
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Performed · outcome unconfirmed · Original poster
I have used the PSM button may times for AutoX, but have never shut it off...
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Discussions that contain suggestions
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Suggestion · Original poster
The display screen continues to display properly and I can hear the flapper doors switching around when I adjust the output buttons.
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Suggestion · Original poster
This might happen every time I pushed the AC button, or not, and it even repeated a few times without doing the off/on on the AC button like the AC unit was trying to run but wasn't happy about something.
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.
16 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.
1 acknowledgements have no verified action link; they do not establish a repair result.
Outcome without a verified action link
Ignition switch changed and while it took the slop out of the key interface activities it didn't fix the fan/A/C issue.
So today after not driving for about one month( yeah I know...) decided to take the 2005(996) C4S for a drive. Ambient temperature approximately 85f so during the drive I had the windows down. While returning home I turned on the cabin fan to move some air around. Nope no fan on any speed setting including Auto nor AC. Couldn't even get the AC "snow flake" to stay on. So once in the garage so I could concentrate on the issue I found the following: If I put system on manual and pushed the AC button within a few to several seconds the snow flake would flash on, I could hear the AC clutch click in and the cabin fans would start. Then immediately all the previous actions would shut off. This might happen every time I pushed the AC button, or not, and it even repeated a few times without doing the off/on on the AC button like the AC unit was trying to run but wasn't happy about something. I checked all the related fuses all good. Did a search here and flipped through the Bentley book to no avail other than possible low freon suggestions. The display on the dash reacts normally except for the snow flake AC indicator glitchiness.
Any thoughts?
Strange problems...
Evap/interior fan should come on regardless of compressor on/off/snowflake position, iirr. Mine do in both my 996.1 & 996.2.
Does the evap fan work in heat mode...?
When it does eventually get into cool mode with compressor/fans on, does it blow cold..?
#1: Yeah my fan used to work the same as yours.
#2: Nope no fan in heat nor vent.
#3: Yesterday it would only click into AC mode for a second(occasionally) which is when the interior fan would come on then drop out almost immediately. Think light bulb flash! It never got fully into AC mode so no cool air ever.
This morning the AC doesn't even try to click in, therefore, no-zip-zero fan...period. The display screen continues to display properly and I can hear the flapper doors switching around when I adjust the output buttons. The fan speed indicator moves properly while adjusting. It seems to go into AUTO and defrost modes. Just no fan nor AC. The Bentley book schematics are pretty sketch on the AC system, but I'll look again. I'm stumped. I'll play with it more Monday. I'm waiting for the rain and lighting to stop to go AutoX...with my Honda Type R. Always good to have a backup!😀
I have seen this problem be caused by the ignition switch ...
Try turning the key back counter-clockwise just a tad and see if the A/c and fan start to work ......
I gave that a try and while it was not a one to one ratio of relationship it did seem to have an affect on the issue. I.e.: After easing the switch counter-clockwise the AC snow flake would try to come on several times when in the previous position it pretty much was a dead fish...nothing.
I'll trying changing the electrical part of the ignition switch and see if that fixes the issue and report back. Thanks for the suggestion.
So playing with things more today while waiting for new ignition switch I can’t get the prior response whether leaving the key normally after start nor going counter-clockwise just a bit. As I was giving up I noticed the PSM button indicator light was on!! No amount of pushing it will make it go off. Strange things happening here. In a former life I was a RR electrician working on diesel electric locomotives so not a stranger to gremlins. I’ve checked the carpet, floor boards and in the frunk…all dry as popcorn! While I was at it I inspected for rodent activity…nothing. I’m going to drag the Bentley book back out and study the schematics some more.
I had issues with my aircon about 12 months ago and it was the ignition switch - hope that works for you. It�s a cheap part but a nightmare to replace. Interestingly my 997 needed a new switch at the same time - easy to replace but expensive part ..
Yeah I�m 74yo, 6�2�, 205#�s ain�t no way I�m crawling under there! They would have to bury the car with me. My indi is not going to like me! So your PSM switch was bad too??!!
Update: PSM self resolved it was user error. I have used the PSM button may times for AutoX, but have never shut it off... Duh! Ignition switch changed and while it took the slop out of the key interface activities it didn't fix the fan/A/C issue. So far the fan relay has been found to be fubar and a replacement is ordered. Will update next week when switch arrives.
Renewed fan relay...nope not that. Now looking at Term XE relay and/or #18 relay for the ac/heating system. Electrical gremlins on a 20 yo car can be fun and "entertaining"!
Ok so today I got bored and switched the XE relay for the horn relay. Numbers 9 &10 in relay support 1. No luck. Interior fan still no workie. So far ignition switch, fan relay(by the fan) and the above. From here I'm going to weed through the schematic as it relates to relay #18 but I think that throws power to the control unit which appears to function properly so we'll see.
Some fun...
Hey Bill! I have the wiring diagram here and I can make a few suggestions.
There are two fuses for the HVAC. Fuse D6 runs the control screen and the flap motors. Fuse E7 runs the interior fan motor and a bunch of unrelated stuff.
You might unplug the 2 wires to the fan motor itself and see if the fan has gone kaput. Jump 12V power to the two terminals and see if the fan runs. The fan motor is exposed to outside air so it can sometimes seize up; mine seized up while driving and all the resulting smoke had me thinking the car was on fire.
There is a speed control module mounted on the HVAC box next to the fan motor. If everything else works and the fan blows air when jumped to power I might suspect this speed control module. It's got a 3 wire plug and has fins that stick into the air stream inside the HVAC box. As I recall it's mounted slightly inboard and above the fan motor.
If you have a PIWIS you could scan the Climatronic for error codes. I am sure those would point the way to find the answer. Perhaps Durametric might be able to scan the Climatronic. I know that generic scan tools won't help here.
Thanks! I appreciate your input. The fuses you mentioned are good. First thing I checked. I will tinker with the other things when it's not 110f in the garage tomorrow morning! I really have to get that deck AC unit ducted into the garage!!!
So finally got out of my lazy chair and the weather moderated. Swapped the #18 relay(on the relay support board 1) out and Yahtzee!! works like it was new! If there is anything nice about this episode is I now understand the Porsche schematics even though they are still a little mysterious!
