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Discussion Starter #1
Hi,

I just got an A/F from autometer. This gauge has the feature that it turns itself on when the battery hits 13.8 volts, witch means it will not turn on before the engine is started - in theory.

In real life I have to rev the engine up to about 3500 rpm to get it to turn on.
What is most likely to be wrong? Voltage regulator or Dynamo?
 

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Check the voltage across the battery terminals with the engine at fast idle. If you get at least 14 volts, your charging system is not at fault, and there is something not right with the gauge or wiring to it.
 

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Discussion Starter #3
Hi, the voltage is about 13,3 at fast idle.
 

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That's not good. There is an alternator output test in the shop manual that can help you narrow it down. Shooting from the hip, it's likely the alternator, regulator, or wiring, but there's really no way to say which until tests are performed or components replaced.
 

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Discussion Starter #5
ok, thanks, Ill have a look in the manual.

Do you have any knowledge on the electronic regultators that looks like the old ones?
Are they any good?
 

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In my opinion, the Motorcraft electronic replacement regulators are superior in every way to the original electro-mechanical units; I use them in both my cars. They eliminate the problems of lights pulsing and flickering, and brightening or dimming when you change the electrical load. If you drill out the two rivets and remove the cover, you can put an original-style cover on them. (This is for the Motorcraft only - I cannot vouch for the reliability or performance of other brands.)
 

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Discussion Starter #7
Hi,
Changed to an electronic regulator now and everything is fine!

Thanks for your help:bigthumbsup
 
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