Light surges...dim/light/dim

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69rangerman
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Light surges...dim/light/dim

Post by 69rangerman »

Is light surge or flicker a common issue? I'd like to solve it if so but would like input on what the cause is and how to address it.

A related question: When I check dwell and rpm on the tach meter and flick the selector to voltage I only get 8-9 but it's a 12v system right? Is this normal?

Thanks for any help,
Tom
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Post by mrsnicks »

Which lights.. instrument... dome... head lights?

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re: Light surges...dim/light/dim

Post by Leadfoot »

any why you look you got to much resistance there, so is it a dirty socket/ connections, old crusty wires, or a bad ground?
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Post by Heavenlyfire »

Also check your alt. belt tension, might be loose. I would even have you alt. tested to make sure it is putting out the right amount of juice.
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69rangerman
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re: Light surges...dim/light/dim

Post by 69rangerman »

Thanks. Actually I've tried to tighten the alt. belt because it does seem a bit loose but I can't get the hanger bolt loose it's rounded just enough to slip on a wrench. I can get the adjuster bolt loose but that's not enough to allow me to move the alt.
I'll get a voltmeter and start working through it. Thanks again.
Tom
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re: Light surges...dim/light/dim

Post by 68F250 »

When does it flicker? At idle only?

The tach or dwell meter is hooked to the coil (-) post. When the engine is running, the voltage at that point is switching back and forth from whatever the battery charging voltage is at that time to ground or zero volts. When the points are open you see battery voltage and no voltage drops from the coil resistance or resistance wire because it's open circuit, when the points are closed you see ground. What you are seeing on the meter is the average of the two voltage levels over time. Actually it's more complicated that that because there is an ac component to the voltage because of the coil spike but your voltmeter response is not fast enough to catch it.
Barry

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69rangerman
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re: Light surges...dim/light/dim

Post by 69rangerman »

I'm don't consider myself a dumb person, but understanding higher math and electrical systems-THAT is some serious brain power. Thanks for being able to get across to me the basic idea of points opening and closing and the tach not catching it. There are several corroded plug ins, and some cracked wire insulation. Usual stuff for old vehicles I guess.
If we are talking about too much resistance where would be a good place to begin the hunt? The battery? Everything works but I have a feeling that things would work better if I could clean some of this up. Thanks for any tips.
Tom
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re: Light surges...dim/light/dim

Post by basketcase0302 »

69,

A good voltage meter will be one of your best friends for working on our old stuff!

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Post by heep70 »

I was told if you switch the regulator from the old tall style to the flater newer style it will solve the problem. I didn't find this out tell I switch over to a one-wire alt so I don't know if it works for sure.
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re: Light surges...dim/light/dim

Post by 68F250 »

It helps a lot but you can still notice a little bit of dimming when stopped at a light, the alternator's not turning fast enough.
Barry

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re: Light surges...dim/light/dim

Post by 69rangerman »

As luck would have it while I was hunting my engine bug down (vac leak) I picked up one from autozone which I haven't installed yet.
I'll give it a try and let you know how it works.
Tom
"O say, does that star spangled banner yet wave? Oer the land of the free and the home of the brave?" It does at my house! God bless America!
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