All dash lights and headlights dim and go bright continuosly

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BirdmansProtege

Member

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2001 Protege

• Aug 5, 2017

• #1

New alternator, battery terminals, resistance checked all cables between alt and bat and all ground cables. All dash lights and headlights dim and go bright also rpm's fluctuate with the lights as well.
It had a bad ground with the brackets the bolt to trans and i cleaned up the contact points and checked resistance as well but still having this issue. When i drive it below 3000rpm it seems to lack power till it revs above that. Anyone have similar issues and what resolved it

 

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naguilar

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2003 Sunlight Silver Mazda Proteg5

• Aug 5, 2017

• #2

I had a similar issue a couple weeks ago with my P5. Had to change the alternator the hard way-taking the intake manifold off. Swapped it and out the belt and harness back together. When I when to crank it found that the interior lights would dim and brightened up.

Upon inspection later on, I found that the belt did not have enough tension. Tensioned it up and the issue is gone. Hope this may be of help!

 

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BirdmansProtege

Member

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2001 Protege

• Aug 5, 2017

• #3

I did try that and had the belt quite tight. Thought maybe i had too much tension on it and loosened it a bit but issue still persists. i had enough tension on it originally so that it moved maybe 2mm when i pushed on the belt to check. I could try and get more tension on it and see if that works

 

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naguilar

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2003 Sunlight Silver Mazda Proteg5

• Aug 5, 2017

• #4

Have you had a chance to check voltage when the car is running?

 

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BirdmansProtege

Member

:

2001 Protege

• Aug 5, 2017

• #5

Not yet. Ill do that right away. New alt though not a reman. Had the same issue with previous alt and that is why i replaced it

 

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BirdmansProtege

Member

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2001 Protege

• Aug 5, 2017

• #6

so the "new" alt jumps between 13.5 and 15.3 Isn't the voltage regulation ECM controlled? Im going to find a diagram and see if that wire is bad if that is the case with ECM control

 

Last edited: Aug 5, 2017

N

naguilar

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2003 Sunlight Silver Mazda Proteg5

• Aug 5, 2017

• #7

Yup! Regulator is ECU controlled. Maybe the alternator is a bad unit.

 

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BirdmansProtege

Member

:

2001 Protege

• Aug 5, 2017

• #8

Could be a bad unit but my other one had the same problem. I checked the wires from the alt to the fuse box and the fuses and they are fine