I can't find the for blower motorin my 1999 jeep grand cherokee

google grand cherokee forums join some of them and ask there

Usually you have to splice the wires into the old plug.
You might be able to find a diagram on the websites for auto parts stores such as autozone.

sounds like either the blower is going out or you have a low voltage with you car

most likly blower reostate or the plug that gos to it from blower known for failing

Maybe bad blend door

replace your alternator thats the problem

not at all. That its a different problem you have. blower motor or vents in general, and gas pump have nothing in comun.

the blower motor resistor is bad replace it and it will work good as new the resistor is located in the same heater box as the blower motor mounted on the outside of the heater box follow the wirring from the blower motor to find it or just simply buy the part and match it up

2 problems?
No blower motor: Blower motor resistor very common or motor itself or heater controls.
No heat: Start simple with check antifreeze level after vehicle has sat for a few hours. If that's OK then it could be thermostat, heater controls, blend doors, water pump, restriction in cooling system

Are you saying that the switches are bad?
Or that when you turn the blower on and select a different temp. it doesn't change temp.?