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Porsche Club GB

Sudden loss of main beam

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

Discussion summary

YOUR RESEARCHSudden loss of main beam

Leading reported evidence

Check engine warning, and had the airflow sensor

Suggestion or failed attempt

No successful repair reported for this finding.

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Reported fixes
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Unsuccessful attempts
1
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Discussions that contain suggestions
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Suggestion · Original poster

Had the car in for code readout for check engine warning, and had the airflow sensor changed for a test one to try for a week.

Sudden loss of main beam
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Leading evidence: 'Check engine warning, and had the airflow sensor' (no explicit attributable resolution; this is a reported action or suggestion). Across 1 matching discussions, The most frequently discussed action is 'Check engine warning, and had the airflow sensor' (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.

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

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.

Check engine warning, and had the airflow sensor

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

Had the car in for code readout for check engine warning, and had the airflow sensor changed for a test one to try for a week.

Sudden loss of main beam
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.

  • Porsche Club GB: 1 discussions

0 evidence records excluded for query context · 2 excluded by outcome qualification · 0 adjusted by outcome qualification.

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

Generation: 20261027T033922Z · outcome-qualification-6. Deterministic extraction; no AI model inference. How we use sources

POST 1 / ORIGINAL POSTEROriginal post

LIke it says. Had the car in for code readout for check engine warning, and had the airflow sensor changed for a test one to try for a week. Have to say the engine idles better not sometimes 1200 rpm just a steady 900. Unfortunately on the way home went for main beam and got nothing, headlight remained illuminated in low beam. Headlight flasher works. Can the high beam be accidentally disabled by the diagnostic lap top. One thing I notice is that if the ignition is turned off with the lights on, then turned back on the reflectors in the Xenon lamps seem to hunt for position and I wondered if something has jammed. This is happening on both headlights

POST 2Original post

The lights are all hard wired, so the diagnostics wouldn't affect them. Only the level control has a control module. Headlight switch. Very common, and there is a DIY in the Technical Articles section.

POST 3Original post

I had the same problem - replaced lightswitch (well, Northway did it or me) and problem solved.

POST 4 / ORIGINAL POSTEROriginal post

Yes thanks guys. I am having trouble getting my head around the switch being responsible for this fault. I would love to study the wiring diagram, but you can't both be wrong. My basic concept of headlight switches is power in power out to a change over relay. this looks like about a 3/4 hour job to me but I might try the box spanner in the tool kit or see if some of my double depth sockets will undo the retaining nut. Just typical as it is going to cost me £250 for the air-flow sensor. and now £85 for the switch.

POST 5Original post

Therein lies the problem - no relays. The full power goes through the light switch.

POST 6Original post

The retaining nut is not tight. I undid mine with angled long nose pliers.

POST 7 / ORIGINAL POSTEROriginal post

Yes that was a stupid thing to say as even on my 924 the full current went through the switch which is why they used to melt with monotonous regualrity. So what happens? Even if the full power goes through the switch the contacts would be rated for it, and on the 944 the contacts on the column switch switch the load. Call me thick but why would you have two outputs from the switch, one for low and one for high when you can just send one output to the column switch and let it switch the load. Maybe it has something to do with the xenons. Don't get me wrong, I am not challenging the informed wisdom, I have already odered a switch, and actually a new switch and two speed fan switch for the 944T work out cheaper from OPC than from a well known independent when you factor in p&p.

POST 8 / ORIGINAL POSTEROriginal post

Now here's the thing, I now have a sudden re-instatment of main beam after driviing the car for about 60 miles. tried a few on/off cyles and many dip/main cycles 'til the locals thought I was around the twist. Apparently in good working order; of course OPC already have my new switch reay to be collected.

POST 9Original post

I think "apparently" is the key word there. They do become intermittent, so I would change it anyway. You don't want a failure at speed..........

POST 10 / ORIGINAL POSTEROriginal post

Yes good thoughts there Richard, I shudder to think of the consequenses should I experience a loss of low beam as well.

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