im getting a squeak from the engine not sure if its alternator or idler pulley I do notice it gets louder when it warms up I do notice that once in a while the lights dim slightly but thats been going on a while trying figure it out now thanks

I just replaced my idler pulley a few months ago because it started squeeking. Do the lights dim when you fist start it and its cold because of the grid heater cycle?

I am with Ryan. If the lights only dim when first starting up (when cold) it is the grid heaters sucking out so much juice. I would remove the belt and hand turn the alternator and idler pulley and see if you can feel any roughness in them. Idler pulley is a cheap fix.