Fan on the ac stopped working. Were is the resistor located.

no car told , just 1999, maker and model a secret and country.
fuses first.
then blower fails on high, does it? if no
there can be a blower resistor on old card.
TOPIC is HAVC
not all cars use a resister on the lows speeds, and not new cars./
most times it is mounting on the blower casing due to that fact it gets super hot and must be air cooled (flow) or burns up.

if car is USA< is it
this works
answer the question and rent the book ,I DO and I pay'.

https://eautorepair.net/Marketing/Default.asp

most resistor blocks bolt to the fan housing, be causes its air cooled
and must be near fan actual so it always is cooled. see?
i just looked,its there. dead center blower case.(fsm book)
alldata.com
log in and read the HVAC pages.
if fan fails on high too, its not the resistor, because on high
it bypassed.
ah but not if the thermofuse in the resistor block is blown

For the ac to stop working either the compressor clutch is not getting power or the gas is too low so the low pressure switch has switched the compressor off to stop sucking in air through the leak. The blower is controlled by the fan switch which is a 3 positional switch that has a resistor for each position. These resistors have a habit of burning out so the fan will not work. The resistors are in a block located in the blower housing. So you have two faults to fix.

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.

You will probably need to replace the resistor behind the dash. Usually the first symptom is the fan will only blow on high but not on the lower speeds. If that is the case, then the resistor ( cheap fix) is the culprit.

If you just lost it all of a sudden, you should check for a bad fuse and will probably find other things that don't work too. Replace the fuse and watch to see that it doesn't go out again - which if it does, you have a short somewhere that needs to be fixed.

Assuming that you have checked the fuse for the fan, the most common problem is the resistor that controls the fan speed. That has been problematic, and BMW has tried several designs for this resistor. Current design part costs about $55 on line. I don't know where it is mounted on this model, but it will be under the dash near the center somewhere.

it is must likely your fan control model -it control's
the fan speed location of model is next to blower

This is a typical  symptom of a failed blower resistor. These have multiple taps for the different speeds but the highest speed just bypasses the resistor completely; that is why it still runs full-tilt.
That resistor may or may not be inside the passenger compartment and could be accessible from under the hood, probably mounted on the firewall or under plastic hoods covering part of the heater/AC exchangers.
I'd recommend buying a Haynes or Chilton manual for your car that should cover the location of that part and perhaps give you information on how to best access it. The books are $17-$30 US and available on line or at any auto parts store and will earn their keep pretty quickly.    

Hi Marc,
I'm not too clear as to which of the two AC fans is not working.....Is it the condenser fan (the one out front of the radiator, mounted at the front of the engine compartment) or the cabin fan?.....either one will stop working in the event of low gas pressure in the AC system.

Is the AC working at all?

The removal of the center consul is not a small job....and to get to the resistor, is also, not very easy....I'm sure that if it is the resistor that has become defective, you'll be able to get one from a breakers yard....They don't usually give problems on the BMW....Incidentally they control the lower speeds of the interior fan operation, but not the high speed, so if the fan works when full and not any other speed, the resistor is the problem.

The fan operation is also fused....A good idea is to check the fuses....

Does the climate control work?

I think I need more clarification and then hopefully I can help a little more....

Best regards Johngee10

The blower motor resister is located next to the fan under the passenger side dash. You will have to remove the glove box and plastic cover under the dash to expose the blower motor. the resister is next to the blower motor.