Ac blower don't work - 1994 Cadillac Eldorado

Have you checked for power and ground at the blower motor ?

check the fuse box

no low freon doesn't have anything to do with the blower, but the click noise you hear is the clutch trying to enguage but not spin, if your blower is working then you don't need to replace the blower, but if blower works but no cold air and freon is at ok levels and the clutch isn't spinning which is in the middle of the ac blower pully then the clutch needs to be replaced, if you add too much freon to the system you can get it to start then stop spinning then spin again on and off untill is at ok levels. i know this because this happens to me every summer in the desert when I recharge my freon.

checked the fuse for the blower motor. if the fuse is good check for power at the motor. the blower motor is behind the golve box.

the large port is the low side. if the cap is on the on the port it will blue.red port is the high side.this does not have anything to do with the blower motor.

I don't even have a 2011 Peterbuilt! ;)
But as in many vehicles when the blower only works in high its due to a bad blower resistor. The resistor is in operation on slower speeds and the motor gets full power and bypasses the resistor on the high speed setting.

As for where it is on a Peterbuilt, again I don't o0wn one so I can't say for sure.
It should be located near the blower motor as it uses the fan blades air to keep it cool.

do you hear the blower running if not then it could be a bad blower motor or a bad relay.hope this helps you.

Yes,your blower motor resistor is faulty.

Look to make sure both ac fuse and relay are good and have good connection, then start the car and turn ac on any change? if not you probably don't have any Freon due to a leak in the lines attached to your ac.

First check the 15 amp HVAC fuse located in the main fuse block inside the car on the passenger side of the center console, under a cover. If the fuse is good, then the problem may either be the HVAC blower switch (which is the fan blower selector switch), the fan blower motor resistor, or the fan blower motor. An auto repair manual will explain and illustrate for you the steps on how to check each of these components.

Even after pushing the ac light switch on, the fan blower selector switch has to be turned on as well (working) because it provides an electrical path to the positive side of the battery to complete the circuit and turn the ac light on. What the ac light switch does is provide the electrical path for the ac compressor clutch to come on through the ac control relay which is controlled by the car's PCM(computer) when you want ac, but the ac light switch still needs to run through the fan blower selector switch to receive its power. You can turn on the fan without the ac light switch because it gets its ground path(negative) from the blower motor. So the blower motor has to work in order to provide a ground path for the fan blower selector switch to be functional. You could have a faulty blower motor which is why no air blows through the vents. The fan blower motor is located inside the car on the passenger side underneath the dash at the bottom end of the glove compartment box. You'll see it. It's right above where a person rests their feet on the floor. Therefore, if your 15 amp HVAC fuse is good, check to see if you have voltage at the blower motor connector. Unclip the connector and with the ignition on and the fan blower switch moved to any one of the first 3 selections, check for voltage using a multimeter. The voltage will vary because there is a blower motor resistor. Voltage should be higher on setting 3 than 1. If you do have voltage at the blower motor connector, check for a faulty blower motor. The auto repair manual will tell you how to do it using jumper wires.

It's normal that your car is running hot because the radiator fan works in conjunction with your ac compressor. If the ac is on, the radiator fan will be on and therefore the engine coolant temperature will stay in it's normal operating range. If the ac is off, the radiator fan will stay off as well and the engine coolant temperature gauge will begin to rise and show pretty hot (especially at idle). It will do this up until a certain degree then the radiator fan should turn on thermostatically and stabilize the temperature. It's scary and I know what your saying because it does that to my car if my ac isn't on. Don't worry it won't overheat.