Why Does Ford Transit Fan Only Works On High? (Solved!)

Many Ford Transit owners have experienced the mystery of the fan not reacting at all in 1st, 2nd, or 3rd speed, but magically working normally in 4th or 5th.

The blower motor is what pushes both heated and cooled air.

And failures in different parts of this system can answer this problem.

This article answers “Why Does Ford Transit Fan Only Works On High Speed 4?”…

Why Does Ford Transit Fan Only Works On High Speed 4?

In the blower motor resistor, each air speed has a resistor, and the more resistors, the current in the electric circuit gets reduced, therefore, the first speeds stops working if there is a failure on the resistor but the last speeds still work because they are powered directly by the fan switch.

The first speed is holding the resistor of 2nd, 3rd, and 4th.

The second speed is holding the resistor of 3rd and 4th.

The third speed is holding the resistor of the 4th.

And the fourth speed, or fifth in some cases, is powered directly by the fan switch and that’s why it can still work.

Ford Transit Blower Motor Structure

Blower motor switch -> Blower motor fuse -> blower motor relay -> blower motor resistor -> blower motor.

The correct (and cheapest) option to diagnose a problem, must be in the order of the structure above.

The blower motor is the one that runs the fan in the heating and air conditioning system.

And the blower motor resistor is an electric resistor used in vans and cars with 4 or 5 fixed speeds, like the Ford Transit, to control the speeds.

Blower Motor Switch

The switch allows you to control the airflow in the vehicle and it should show some failing signs before failing completely.

For example, erratic operation, like working at some speeds but not in others.

Even though, it could be the problem of the fan only working on high, is not very likely.

For instance, if it is the problem, the van’s symptoms would be working at random speeds and not only in the high ones.

Blower Motor Relay Wear Out

If the blower motor is not functioning at all, that might be because the relay is worn out, therefore, is not sending any current in the circuit.

The relay is also working together with the fuses, if they get blown, the power distribution is limited.

On the other way around, an excessive current from a failing relay can cause a blown fuse.

A failing relay can also get very hot due to high current loads, and this can lead to getting burned or melted.

Ford Transit Blower Motor Resistor Not Working

The resistor can fail if it is corroded or overheated or it might fail due to a problem with the blower motor itself.

For example, it can get overheated if leafs or other objects are getting inside and reaching the fan blade.

How To Test The Blower Motor?

By measuring the voltage in the motor when is running.

It should be between 4 to 6 volts at a low speed and around 12 volts at a high speed.

If with these volts the motor doesn’t run, or if there are no volts at all, the blower motor is probably damaged.

Ford Transit Blower Motor Location

Depending on the year of your Ford Transit, your blower motor can be located behind the center of the dash, behind the glove box, or under the hood.

Blower Motor Control Module

In vehicles with an automatic climate control system or with a blower speed that can be controlled gradually, there is an electronic blower motor control module.

This one controls the speeds instead of a blower motor resistor.

For example, the one in vans and cars with 4 or 5 fixed speeds like the Ford Transit.

How Much Does A Blower Motor Cost?

In the following table, we have layout the average fixing cost of the different parts of a blower motor system in a Ford Transit:

RepairLabor FeesPartsTOTAL
Diagnose Inspection100 $100 $
Blower Motor Relay110 $10 $120 $
Blower Motor Switch110 $60 $170 $
Blower Motor Resistor110 $100 $210 $
Blower Motor110 $125 $235 $

How Long Should My Blower Motor Last?

A blower motor should last as long as the vehicle does.

But their lifespan can be reduced to even 10 years due to weather and/or outside conditions.

Dirty Blower Motor

There are two types of people when it comes to vehicles:

The ones that don’t change any piece unless is broken.

The ones that make prevention maintenance to avoid the failure of the parts.

With time, your blower motor will get dirty and eventually clogged, causing your blower motor to work harder and eventually leading to failure.

How Often Should I Clean The Blower Motor?

For the people that prefer preventive maintenance, a good cleaning by removing the piece, performed by a professional, is the best option to keep in shape your blower motor.

Depending on the conditions, every 65.000 to 100.000 miles.

Blower Motor Relation With The Compressor

A long-time failure in the blower motor that is not repaired will put a big stress on the compressor and shorten the life of your A/C system.

Other A/C Problems

Besides the blower motor, here are other common problems with your A/C:

Refrigerant Leak

A leak in the A/C hose that can be patched with sealant.

Blocked Condenser

If something is blocking the condenser, this one will not be able to cool the hot refrigerant and therefore your van will only expel hot air.

Broken Condenser

Usually caused by a cutting object.

Electrical Problems

Broken or burned wires.

Faulty Compressor

The compressor is the main component in an A/C system.

A piece to be very careful with, since is the most expensive one of the system and in case of bad damage, is impossible to fix.