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gauge needles bouncing
I was curious since I have not noticed this before, but I just noticed the needles on my gauges bouncing while driving on these rough Louisiana roads. The gauges that seem to be bouncing are the Tach,the druck pressure gauge and the temp needle.
Is this normal that the needles are bouncing or is it a sign that I have either electrical problems or gauges going bad.
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Phil 2005 GT3 Milltek Exhaust/ECU reflashed/OEM Short shift 1988 911 coupe (GP white) Turbocharged 1998 BMW 328i |
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nice doggie
Join Date: Oct 2002
Location: Denver, CO
Posts: 1,478
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You may have a relay that's going south.
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Jerry 78 SC hotrod 02 Mini Cooper S |
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I had something similiar. First it was the pressure and temp. Then the RPM started going all over the place. Most on the board suggested it was the voltage regulator. I pulled the alternator and noticed it was original (has the built in voltage regulator) and decided to replace the whole thing with a rebuilt.
Of course, I had a while I was at it moment and started working some other electrical problems. I'll be installing the rebuilt alternator this week so I hope that fixes all my problems. Michael
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1999 996 C4 Cabriolet 1997 BMW M3 (Hail) 1985 928 S (Sold) 1982 SC Targa (Sold) |
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check the grounds - then the relay, then Vreg, alt., etc.; bad gauges are the least likely explanation...
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"A man with his priorities so far out of whack doesn't deserve such a fine automobile." - Ferris Bueller's Day Off |
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I should add, I checked with a voltmeter to see the voltage spike.
Randy brings up an excellent point on the progression of checks. He's the one that helped me diagnose my issue. One thing, how do you check a relay?
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1999 996 C4 Cabriolet 1997 BMW M3 (Hail) 1985 928 S (Sold) 1982 SC Targa (Sold) |
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On my relay, I took it apart and looked for burns or wear on the contacts. I also posted some pics with questions. Then as I was trying to get it back in the poorly located hiding place the Germans found for it... it crushed. So I bought a new one...
That's how I "checked" mine....
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"A man with his priorities so far out of whack doesn't deserve such a fine automobile." - Ferris Bueller's Day Off |
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I'll do all of the following checks Randy suggests tomorrow, but just out of curiousity....my gauges only do this while traveling on rough roads..I just took her for another drive and noticed that the gauges were acting normally, only when I hit rough road does it do this, so I am thinking maybe a bad connection somewhere. But I'll check tomorrow
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Phil 2005 GT3 Milltek Exhaust/ECU reflashed/OEM Short shift 1988 911 coupe (GP white) Turbocharged 1998 BMW 328i |
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Check your battery terminals too. Unscrew them, clean them with a wire brush, and rescrew them. Very often, a ohmic drop there will cause these symptoms.
Aurel
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1978 SC Targa, DC15 cams, 9.3:1 cr, backdated heat, sport exhaust https://1978sctarga.car.blog/ 2014 Cayenne platinum edition 2008 Benz C300 (wife’s) 2010 Honda Civic LX (daughter’s) |
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