Flatbed24v

My ac and heater only works when the fan speed is on the highest setting, it just did this today out of the blue, any ideas on how to fix this??? Thanks!!!!

m.t.hands

i had to replace what i'm gonna call a fan relay, it was mounted on the blower motor housing, look up from floor-board and you can see it right to the side of the blower motor...seem like the part cost me 50-60 bucks

swordfish

Its your fan resistor. I have had to replace mine a few times. Unplug the wiring harness and then two phillips head screws and it comes out. More than likely your ceramic material will be cracked or broken. Like m.t.hands said about 50 bucks. Its in the location he stated...Not a hard job.

swordfish

Don T

When you install the new resistor , add something to protect that connection from water and rust. It will last much longer and you will not have this issue again. just saying lol.

Colorado_hack

If you don't need it right now the cheapest place I found for it is genosgarage.com. 35.00 if memory serves me right.

haulin-rv

Mine lost low speed only, same fix??

SIXSLUG

Yeah, when they start to go out they will eventually only run on high.

You can expect about 60-70K miles out of them, normal useage.

Flatbed24v

Thanks guys, is this part a common part at most auto parts stores??

m.t.hands

i tried to locate my reciept, i believe mine came from NAPA

Busboy

The reason they burn out is they get too hot from lack of air flow and too much amperage draw. This is often because the bearings in the fan motor are too tight. Check your fan motor.

swordfish

+1....I had to replace my resistor a second time after about a year or so. Heard from another member to change out the fan motor if I keep blowing resistors. I swapped the motor out and it has been good since.

swordfish

AggieJustin

Will this also affect the speed of the fan on lower settings? Mine still runs on all four speeds, but it seems like I'm getting less airflow on 1-3 than I used to. In the past I would run it on 2 most of the time, now I find myself keeping it on 3.

Busboy

The resistor block gives you the different speeds, it will not slow down the speed with age. If you find your fan speeds overall have gotten lower it is most likely the fan motor bearings and by removing the motor and squirrel cage you can easily check it just by rotating it by hand. The other reason you may have lost fan speed is.. all air has to pass through the evaporator, (not all air passes through the heater core) the evaporator can become clogged with leaves and debris reducing air flow. There is no reason for the resistor block to fail other than overheating caused by low air flow and/or high amperage draw from the motor.