Gen/Fan Light Flickering

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SeamusNZ
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Gen/Fan Light Flickering

Post by SeamusNZ »

Hi from New Zealand,

My '62 Spyder has developed a new problem since I wired up the courtesy lights, heater fan and wiper motor.

The Gen/Fan light is flickering intermittently even when the car is traveling along and at 2000 revs. It ranges from a dim flicker to the light remaining on quite brightly, regardless of revs. I have also noticed that the courtesy lights flicker, particularly at idle.

I have checked the battery with a meter showing 12.7 volts when not running and 14.5 volts when running, so the Alternator seems to be charging the battery ok.

I have had no problems with flat battery or anything else.

Any ideas.

Kind regards from NZ.

SeamusNZ
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Shonan
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Re: Gen/Fan Light Flickering

Post by Shonan »

If it was me , I would disconnect what I just wired up and then run the car to see if it clears. If it does then you know it is caused by something you wired in. Then I would connect one item at a time do the test drive and see when the conditions occur. That would isolate the area you need to look at. More experience folks here and maybe they have seen this before. But for troubleshooting purposes, I think isolating problem first from front to back, then that will leave you with an area to pinpoint the problem .
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SeamusNZ
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Re: Gen/Fan Light Flickering

Post by SeamusNZ »

Thanks for your prompt reply and advice Shonan,

I tried disconnecting everything one at a time but no luck I'm afraid. It would appear to be an isolated problem unrelated to the other systems. I have noticed though that when the Gen light is brightest, it dims considerably when I put the heater fan onto high???

Kind regards...

SeamusNZ
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bbodie52
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Re: Gen/Fan Light Flickering

Post by bbodie52 »

Alternator ID.jpg
From the picture of your engine you appear to have a Delco Remy model 10 SI internally regulated alternator with an output capacity of 37 A.

This alternator has the lowest output capacity of the 10 SI series. Many have a capacity of 63 A or greater. I'm just wondering if the additional electrical accessories you have wired in have exceeded the capacity of your alternator, or if there is a possibility of an internal regulator problem or possibly a problem with the alternator diodes.

If you disconnect all of the new accessories that you have wired in, does the problem with the generator warning light disappear? Have you checked all the connections on the alternator to ensure that they are clean and tight?

What battery voltage do you read when the accessories like the heater fan are turned on high? Is the charging system keeping up with the demand?



Brad Bodie
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dave t
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Re: Gen/Fan Light Flickering

Post by dave t »

Is your battery negative wire secure at the battery, frame and engine. If your frame ground is bad and engine ground good then the frame/body is grounding through your rear wheel bearings. Not a good thing and can cause lights to flicker. Check your grounds.
However. Your gen light has 12v on one side and gen wire on the other side. When both wires are at the same voltage, the light does not light. When there is a differential between the wires, such as lack of charging, the lamp lights.

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Jerry Whitt
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Re: Gen/Fan Light Flickering

Post by Jerry Whitt »

Many auto parts stores are happy to test your charging system. One test that might help is a usage test. With the engine not running, the ignition switch is turned to the on position, head lights turned on high beam, radio on, wipers on, door open and any other electrical devices turned on.
Measure the usage. If the usage is more than the alternator can produce, the culprit has been found.

The test is done with a special volt meter hooked up to the battery and a probe place around the positive battery cable. Please let us know what you find.
Jerry Whitt
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SeamusNZ
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Re: Gen/Fan Light Flickering

Post by SeamusNZ »

Hi all,

I finally figured out why my Gen/Fan light was flickering while the car was running. Thank you for the attached videos, they were very helpful in solving the problem.

I took the alternator apart to check the diodes and found that the insolated screw that was fixing the diode trio to the brush holder was shorting out. The insulator sleeve protecting the screw had melted slightly allowing the screw to intermittently come into contact with the diode trio.

Once I put an insulation washer under the screw head, everything was back to normal.

Thanks for all your help.

Kind regards from New Zealand,

SeamusNZ :guitar:
Attachments
Insulated screws
Insulated screws
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