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Alternator Warning Light - Led Replacement

electrical

Best Answer Spider , 18 April 2017 - 08:10 AM

I use a straight out LED with a 70 Amp Alternator and have no issues.

 

Some Alternators need a 2.2 Watt lamp or load on the IND Terminal to kick off excitation and others, like the 70 Amp Alternators don't need that much load. It does need something there though, as if this is disconnected, it won't work, but an LED does have enough load.

 

If you find your alternator does need load, fit a 5 watt, 68 ohm resistor across the LED for load. Be sure to leave some space around it as it will get hot but only when the LED is lit up.

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#1 Monteemini

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Posted 17 April 2017 - 11:31 PM

Hi,

 

I have had an issue for a while where the alternator has not been charging the battery.

 

However after reading this topic http://www.theminifo...y-not-charging/ DKLawson mentions that the charge warning light must be present.

I don't have a charge warning light connected so this looks like the problem.

 

However i am not running standard gauges so i  need to wire up an LED, DKLawson mentioned that an LED on its own will not allow the desired currency for the coils in the alternator to energise.

 

Ant ideas on how i over come this issue?

 

Thanks

 



#2 russo

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Posted 18 April 2017 - 12:16 AM

Hi, if you have an LED for an ignition light you will also have to fit a bulb type light as well as the LED. As an LED will only allow current to flow one way and hence your alternator will not charge due to the back feed from the bulb it requires to allow it to function.



#3 Monteemini

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Posted 18 April 2017 - 07:43 AM

Hi, if you have an LED for an ignition light you will also have to fit a bulb type light as well as the LED. As an LED will only allow current to flow one way and hence your alternator will not charge due to the back feed from the bulb it requires to allow it to function.

 

Thanks that makes sense, presumably i hook the bulb up in parallel with the LED, thus giving bi-directional current bypassing the LED?



#4 Swift_General

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Posted 18 April 2017 - 08:03 AM

Yep wired in parallel. Or simply use a resistor of appropriate value.

Edited by Swift_General, 18 April 2017 - 08:06 AM.


#5 Spider

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Posted 18 April 2017 - 08:10 AM   Best Answer

I use a straight out LED with a 70 Amp Alternator and have no issues.

 

Some Alternators need a 2.2 Watt lamp or load on the IND Terminal to kick off excitation and others, like the 70 Amp Alternators don't need that much load. It does need something there though, as if this is disconnected, it won't work, but an LED does have enough load.

 

If you find your alternator does need load, fit a 5 watt, 68 ohm resistor across the LED for load. Be sure to leave some space around it as it will get hot but only when the LED is lit up.


Edited by Moke Spider, 18 April 2017 - 08:12 AM.


#6 Monteemini

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Posted 18 April 2017 - 08:20 AM

great thanks guys, i will see if the LED alone will allow the alternator to run.

 

If not i'll put a resistor in parallel with it.



#7 Ethel

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Posted 18 April 2017 - 09:16 AM

You'll lose a little bit of funcionality. A bulb glows proportional to the difference in voltage difference between the alternator and battery and, being biderectional, also shows if the alternator is overcharging.







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