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Throw it on the ground!
Join Date: Aug 2006
Location: Atlanta, GA
Posts: 2,568
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Headlights dim when A/C compressor kicks in?
I've recently noticed that my headlights dim when the A/C kicks on. It seems more noticable at low RPM's or at idle. Is this normal? Any cause for concern?
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Mark 1987 911 Coupe Granite Green Metallic My Cousin's Wife's Sister's Husband is a Lawyer. |
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12-19-2008, 04:33 AM
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Probably just your rpm dropping with the compressor coming on.
Do they brighten up if you bump the revs up? I don't think it is anything to worry about.
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Bill K. "I started out with nothin and I still got most of it left...." 83 911 SC Guards Red (now gone) And I sold a bunch of parts I hadn't installed yet. |
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12-19-2008, 04:41 AM
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sudo apt-get purge 930
Join Date: Jul 2006
Location: Brandon, FL
Posts: 4,838
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Has it always done this? It's not uncommon for this to happen on some cars at low RPM but if it wasn't happening before then something has changed. The A/C is a load on the engine and when first turned on the load is greatest for a moment. It's sort of like inrush current on an electrical circuit, like when the garage lights might dim momentarily when an air compressor starts. If it wasn't doing this before then you need to check your charging circuit, from the alternator to the battery and every ground and connection between. I'd start with checking the alternator output voltage and see what you get.
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Mark 1979 930 Euro ***GONE AND DON'T MISS IT AT ALL*** "Worrying about depreciation on your car and keeping mileage down is like not ****ing your girlfriend so her next boyfriend finds her more appealing" --clutch-monkey |
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12-19-2008, 04:47 AM
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Throw it on the ground!
Join Date: Aug 2006
Location: Atlanta, GA
Posts: 2,568
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Yes, they do brighten when the engine revs up. I notice this mostly at stop lights or driving slowly (most of the time
 ) through the parking garage at work.
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Mark 1987 911 Coupe Granite Green Metallic My Cousin's Wife's Sister's Husband is a Lawyer. |
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12-19-2008, 04:52 AM
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sudo apt-get purge 930
Join Date: Jul 2006
Location: Brandon, FL
Posts: 4,838
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Have they always done this or is it something new?
__________________
Mark 1979 930 Euro ***GONE AND DON'T MISS IT AT ALL*** "Worrying about depreciation on your car and keeping mileage down is like not ****ing your girlfriend so her next boyfriend finds her more appealing" --clutch-monkey |
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12-19-2008, 04:56 AM
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Throw it on the ground!
Join Date: Aug 2006
Location: Atlanta, GA
Posts: 2,568
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Quote:
__________________
Mark 1987 911 Coupe Granite Green Metallic My Cousin's Wife's Sister's Husband is a Lawyer. |
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12-19-2008, 08:30 AM
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sudo apt-get purge 930
Join Date: Jul 2006
Location: Brandon, FL
Posts: 4,838
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Quote:
__________________
Mark 1979 930 Euro ***GONE AND DON'T MISS IT AT ALL*** "Worrying about depreciation on your car and keeping mileage down is like not ****ing your girlfriend so her next boyfriend finds her more appealing" --clutch-monkey |
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12-19-2008, 08:33 AM
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1983 Porsche SC
