Blower fan makes a high pitch squeal. Seems louder on low.Replaced the fan but squeal is still there.

high pitch squeel usually comes from the cambelt

Above the passenger's feet, 3 bolts to loosen and it comes right out...

To address your first problem squeaking brakes aka "brake squeal", is most often casued by one or 2 things: "Pad vibration" or a "low brake warning sensor".

Pad vibation is usually caused by ineffective pad anti-rattling clips & hardware that allow the pads to vibrate at a super fast speed whenever the brakes are applied, thus causing a high pitch brake squeal. To correct this, replace all the pad hardware and anti-rattling clips and make sure you use a quality pad set that has anti-rattling plates attached to the backs of them. Weather conditions do affect brake squeal, that is why it seems to be worse at times.

Low brake warning sensor squeal occurs when your brake pads reach the point of replacement, the sensor attached to the pads scrapes on the rotor which produces a high pitch squealing sound to warn you it's time for new pads.

As far as your second problem goes (a knocking sound), I'll need more information about the problem before I can offer a possible cause (eg. happens on left or right turns, while going over bumps, at high or low speeds, accellerating...).

I am having this same issue. I have changed my brakes and now I was going to change the front wheel bearing, but unsure to dump a lot of money out on an unsure fix.
Let me know if anyone has a fix?

I'd check the passenger side mirror first, make sure it is tight to the window frame, no gaps. It causes a wind noise or whistle. It could be from the outside of the truck, try to pin point. Does noise go away with either window down? Does noise get louder turning in one direction (wheel bearing)? Does it get worse then seem better (could be tire noise)? Eliminate fan motor, and radio. Does it get worse with vehicle speed or just engine speed?

Mine has a high pitched whistle at high rpms and I can't figure it out. But mines def not the tranny. I'm thinking it's a vacuum line somewhere. It's a 97 2.3l manual. The colder it is the louder...

it could be the engine belt or the brakes are bad listen to where it coming from and you will know which you have to change

loose fan belt?

Put the car in neutral, set the parking brake, open the hood, get someone to listen/see where the sound is coming from, as you press on the accelerator.

Seems like a drive belt problem, to confirm pour some water on belts the noise should go away or may get louder for a second. If either happens the belt or belts needs to be adjusted or replaced. Good Luck, If I fixed ya, leave me a FIX-YA comment thanks