| Head light / Alternator Issue Sylvania High performance seald beams. [message #116346] |
Thu, 24 February 2011 10:58  |
gbarrow2
Messages: 765
Registered: February 2004
Location: Lake Almanor, Ca./ Red Bl...
Karma: 3
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I recently noticed that my headlights dim and then re-brighten (is that a word?) frequently while driving at night.
Last night I noticed that when the lights dim the alternator/amp meter goes negative. It only lasts for a few seconds and then the ampmeter switches back to positive and the lights come back up.
Any suggestions as to finding the cause of this and repairing it?
I have never been happy with the light from the stock headlights but have not wanted to install one of the upgrade kits that have been discussed on this forum.
Last week I bought some Sylvania High Performance Lighting sealed beams ($19 and change each at O'Reilly's) They made a huge difference. I guess the bulb technology has changed a bit. No need to change anything else with these bulbs.
The fluctuating brightness issue existed before and after I changed the bulbs so that's not the cause.
I have never noticied the ampmeter fluctuating when driving without the lights.
I'm not having battery or charging problems yet. The engine battery is about 6 months old and the house 6v batteries are only 2 years old.
I did not notice the alt light come on when the ampmeter went negative but I did not specifically look at the light.
All suggestions will be appreciated.
Gene Barrow
Lake Almanor, Ca.
1976 Palm Beach
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| Re: [GMCnet] Head light / Alternator Issue Sylvania High performance seald beams. [message #116369 is a reply to message #116366] |
Thu, 24 February 2011 13:09  |
Ken Henderson
Messages: 8726
Registered: March 2004
Location: Americus, GA
Karma: 9
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Sorry, but the negative-going ammeter pretty much rules out the battery
connections. There's an intermittent short somewhere. Look for chafed
wiring somewhere -- could be in the tail light wiring, but it's more likely
in the headlight wiring because it's not fuse protected (for safety reasons)
and tail lights are.
The voltage regulator is a possibility, but I'd say the probability is small
compared to the short. An intermittent regulator might not be found by a
short parts store test.
Ken H.
On Thu, Feb 24, 2011 at 1:45 PM, Emery Stora <emerystora@mac.com> wrote:
> First check your terminals at the battery to make sure they are clean and
> tight.
> If they are all right then you might be having a voltage regulator problem.
> It is built into the alternator. Take the alternator to an auto parts
> store for free testing.
> It might need replacement.
>
> Emery Stora
>
> On Feb 24, 2011, at 10:36 AM, gene barrow wrote:
>
> >
> >
> > Emery,
> > Thanks for the reply. I'm sure there is a message in there some where but
> I can't find it. Lost in the ether.
> > --
> > Gene Barrow
>
>
> _______________________________________________
> GMCnet mailing list
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Ken Henderson
Americus, GA
www.gmcwipersetc.com
Large Wiring Diagrams
76 X-Birchaven
76 X-Palm Beach
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| Re: [GMCnet] Head light / Alternator Issue Sylvania High performance seald beams. [message #116375 is a reply to message #116369] |
Thu, 24 February 2011 14:25 |
pickle4k
Messages: 129
Registered: January 2011
Location: San Leandro
Karma: 0
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Hi Gene,
I usuall rewire upgraded headlights with relays when I redo an old car. Some Halogens require more juice than our old wires can safely provide, which can lead to wire melt.
I simply run a new wire from the headlight switch to a relay behind each headlight and a 12 gauge wire from the battery or other heavy duty hot terminal to each relay. Then wire the relay with a ground and new pigtails to the headlights. You will have a new system and unless the headlight switch is defective it provides all the 12V you will need. Summit even sells a kit for this.
Nick R.
Nick R. NorCal
76-23'Transmode-Norris
Rear Bath and
75-26' Avion
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| Re: [GMCnet] Head light / Alternator Issue Sylvania High performance seald beams. [message #116420 is a reply to message #116375] |
Thu, 24 February 2011 20:18 |
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mike miller
Messages: 3576
Registered: February 2004
Location: Hillsboro, Oregon
Karma: 0
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| pickle4k wrote on Thu, 24 February 2011 12:25 |
...
I simply run a new wire from the headlight switch to a relay behind each headlight and a 12 gauge wire from the battery or other heavy duty hot terminal to each relay. Then wire ...
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Good and recommended modification. For less than the cost of wires and separate crimp connectors, you can find wiring harnesses several different places to do this... with nice heat shrinked connections and plugs. (Most will need to have one side extended to fit our GMC's.)
But when you mount your relays, mount them with the connections down.
The PO of my '77 mounted them behind the headlights with the connections up. He never drove it after doing this modification but the relays collected water and rusted out.
Mike Miller -- Hillsboro, OR -- on the Black list
(#2)`78 23' Birchaven Rear Bath -- (#3)`77 23' Birchaven Side Bath
More Sidekicks than GMC's and a late model Malibu called 'Boo'
http://m000035.blogspot.com
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