I've searched but have not found what I'm looking for. I drive an '86 4runner and need the ac to work better. The blower sounds about like a tornado and i pretty much have to yell to communicate with people that ride with me but there is very little airflow from the vents. I've took apart the ductwork and it's all clear with no sign of mice that could be blocking airflow. Do y'all have any ideas of what the problem could be?

 

My 89 is the same way ,I am thinking the fins in the evaporator are plugged.So far I haven't had a chance to try and clean it, so if anyone has a good way to get to it let us know.

 

Does it start out like this or begin blowing week if you've been driving for a while. If it blows good then slowly gets weak, your evaporator is freezing up and not letting air flow. If it always blows slow but sounds like a tornado, probably a dirty evaporator. Do you have all of the original sensors/switches (thermistor)?

 

Swampfox, bad news you must remove the gas and disconnect the suction and high pressure lines to get the cooling box (evaporator) out. This is all located behind the glovebox. Don't be intimidated. It's really easy to do once the gas is removed

 

As said above, the evaperator is probably pluged with dirt and leaves, and its very hard to clean with out removing it and opening up the evaperator box to clean it out.

If you remove the dash you might be able to get it a part to clean it out. Removing the dash isn`t hard, its more time consuming than anything else.
Ive replaced the heater cores in two 86 4Runners so im speaking from experiance.

 

Here are some possible symptom reasons..


Blocked air inlet.
Clogged evaporator fins.
Frosted evaporator.
Air leakage from cooling unit or air duct.
Defective blower motor.
Faulty wiring connections.

Good Luck!

 

Thanks for all the input. It does start slow then I believe it does get weaker. As far as I know I know its all the original sensors and switches. I'll check the evaporator to see how dirty it is and clean it out. Hopefully that will fix it. Should it be blowing as hard as my dad's 94 4runner, or at least kinda close? I assume it cant be that good since his is a newer model but I'd like to know about how strong it should be.

 

It should be blowing very similar to your dads 94 4Runner,

 

Could be dried out bushings or worn out brushes:
- http://www.4crawler.com/4x4/CheapTri...ml#MotorRepair

 

Thanks rbroomba,I was in hope of a solution that did not require evacuating the system.There is a spray on cleaner for cleaning and deodorizing the evaporator,but you still need to get the trash blown out first.

 

Today I took some time to look into my evaporator issues. What I ended up doing was removing the glove box dash area, blower motor and setting the dash controls to recirculate.What this did was give me some access to the evaporator core.With the recirulate door open it allowed a long blow nozzle to be inserted threw the air intake for the cab, to blow the evaporator core out partially. If you have a small flexible hose that could be taped in the end of a vacuum cleaner hose it would help in cleaning the area.
My evaporator had leaves and a paper towel blocking things up.The compressed air did a good job ,but you need to be careful when inserting anything in the evaporator area. There is a small tube in the box that senses the temp ,and if it gets broke the ac system will stop working.
It was fairly easy to do ,if you live in dusty conditions you may send a dust cloud into the cab, and the blower motor is pain to r/r, but if you loosen the housing bolts it will make it a little easier to reinstall.
It made big difference in my truck hopefully it will work for others also.

 

The problem is definitely a clogged evaporator. I cleaned it out the best I could without removing it and I have much better airflow but not the best. I used CLR and a water hose to spray it out. I plan on taking it out soon so I can thoroughly clean it.