I installed a new alternator now the check engine light is on

 

I will make a deal with you; tell what year, engine size and what code is set due to the CEL, and I will tell you about it.
And it will be free.

Good luck.

 

And Bluegrass will be right.
Besides, do these even have a SES light? Or just CEL?

 

We cannot tell until more info is given.
After 04 and on later model years as they progressed, there are CEL codes associated such that the repairs get much more complex.
Never ask a question without giving at least baseline information because we are not yet at the stage of telepathy.
Good luck.

 

Besides it could be a Kia he is asking about.

 

I am hoping it is for a 97-03
Since that's where it is posted. But I should know better.

 

I will ask, do you want help or not?
You take the time to reply but still with no information.
What is the year?
What is the motor size? There are 4 engines possible.
What dash light is on? The Check engine or the charge light?
If the check engine, what code is set?
PLEASE!
Good luck.

 

I did a little digging for info.
Unless your talking about some other truck, you have an 01 with a 5.4.
With over 2800 replies, you should know better by now.
If there is a CEL, what is the code causing it to set?
Is it the charge light?
Good luck.