Does ac blower have a fan relay ? It doent blow ******* max

i will now read the online service manual to you.
https://eautorepair.net/Marketing/Default.asp

blower fan located where. dash heater blower fails
or radiator fans of some odd kind added later.
coolant fan or dash? there are 2 coolant fans and 3 relays to run them and all 3 relays, can fail and coolant fans blow for ever and ever. fuse 6 kills the relay coils. only, so if relay is welded fans blow endlessly. even if bcm is removed from the car.
on the other and the heater blower is 100% controlled by the BCM

so car engine starts and runs and drives ok right.
when did car last run perfectly> , or seen ever ?
service manuals for 88 cars are not easy to find
means real oem manuals, best. 35 years old !
no digital then ,just a huge paper bound book, remember?
holy moly this 88' has a body controller here, bcm , relic amazing thing.
facts: 1988
here is proof

it sounds like the fan resistor is faulty location of it will be attached to the fan structure or if not trace the red and black power wires coming from the fan it will be mounted close to the fan

HI SPEED BLOWER RELAY PERHAPS

Sounds like high blower relay is bad

if your engine is overheating could be the problem of the ac not working , check the temperature sending unit located by thermostat housing , if it is bad will not let the radiator fan come on when ac is on and will cause your high side pressure ac line to get to hot causing the high side switch to disable the fan , also check the blower motor resistor it controls speed of blower motor

Power goes thru the rear blower relay, then the resistor and motor. The fan control switch provides the ground connection. I would check the rear blower relay if power is questioned at the blower motor.

if it blows air only on forth speed then the blower motor resistor is faulty

Check fuse supplying fan is not blown,
Check blower control switch is operating OK,
Check relay controlling fan is operating OK,
Check variable speed resistor pack is not faulty (the resistor pack is usually located in the blower ducting, in the blower airflow),
Check blower motor ground connection is not missing.

It seems the AC switch is faulty maybe it doesn't contact the compressor wire on the MAX.
Check the switch.

if the blower works sometimes check the blower motor resistor which should be located by the blower motor