bat. light

[uglyryder]

first off i want to thank you guys, this is my first post but thats because every time i needed to know something you guys had already figured it out. but i search this time and i didnt see anything, but i hope you guys can help me out.

I have a 2001 xlt 4.6 ive had it less then a year, and the whole time ive had it the battery light comes on when ill push the pedal to the floor to pass someone. it wont come on at first but before i can pass someone it will and if its at night i can see my lights getting dimmer.

im gonna guess its the alternator because i bought a new battery for it just a few months ago. well thanks in advance.

Jon

 

[ELVATO]

Yea, it's most likely the alternator. You can get that checked for free at Advanced Auto or Auto Zone.

You can get an alternator there while you're at it. Also, a serpentine belt removal kit wouldn't be a bad idea as you need to loosen that to get the alternator off.

 

[Grasshopper]

A serpentine belt removal kit?!?!

Just use a 1/2" socket wrench in the tensioner pulley.

Also, you gotta be smart about getting alternators from parts stores. They are reman's and are somewhat hit and miss.

 

[dan1a1984]

I would try changing out the belt first. sounds like it might be slipping. if the Battery light only comes on when your are heavy on the foot. Take a multimeter and measure your the battery with the truck at idiling. then have someone press down the on the gas (with the truck in park) and watch the meter. The DCV should go up when you press the gas not down. Also watch and listen to the belt, if it is making a high pitch sound it needs to be replaced.

This is a cheaper option that i would try first.

 

[ELVATO]

I figured the serpentine kit would make the job easier, and it doesn't cost anything. (40 to rent, then you get it back when you return it)