headlights dim when accelerating

[Guest]

When I accelerate, the battery light flashes on and the headlights dim. When the rpm drops back, the lights are normal. I have replaced the battery and belt. Does anyone know how tocorrect this?

 

[monsta]

New alternator.

 

[Guest]

Originally posted by monsta
New alternator.

i agree

 

[smo0othride]

or have the one you have rewound

 

[Keydo]

Maybe your belt needs tightening? I know there is an automatic belt tensioner in the engine, but it's just a thought.

But if not that, then I'd suspect the alternator.

If you have a voltmeter, run the engine to the RPM where the lights dim and check the voltage.

It should read over 12.5V. If not, then something is going on.

 

[Guest]

yes i have your answer, we have a shop and spoke with ford b/c i was having this same problem. The solution is not the alt its self its the voltage regulator on the alt. the simple test is to short to ground on the back of the alt. we did this and it straightlined at around 17 volts which it should have. that means its the voltage regulator. another tip is believe it or not but this part is CHEAPER from the dealer than an aftermarket part. I think this part costs around 59 dollars from the dealer and you have to remove the alt to replace it.. hope this helps.. brian

 

[monsta]

Last alternator I had had the regulator as part of it. I couldn't just replace the regulator. Hence, my "suggestion".

Glad you found the problem and it was cheap to fix!!