Location of blower motor switch resistor on 2004 Grand Marquis

You might need a blower resistor. Should be located under the hood at the inlet to the air box.

Here's a video Joe on your blower motor resistor. How to Replace Blower Motor Resistor Ford Crown Vic

its locate under the hood at the front of the car on the driver side.

• For this a 2004 Grand Marquis the blower motor resistor is located on the bottom of the heater/AC housing on the passenger side of the car under the instrument panel. You need to remove the glovebox off from the instrument panel to replace it.

• To change it follow these steps.

1. Remove the neg battery cable from the battery.
2. Wait 5 minutes before moving on. This is important to wait or you risk the air bags accidentally deploying.
3. Remove the glovebox from the instrument panel.
4. Pull out the lock on the blower motor resistor wire harness connector to unlock the connector latch.
5. Depress the latch on the connector and unplug the connector from the resistor.
6. Now remove the two screws holding the resistor in place.
7. Now remove the resistor.
8. Revers steps to install new on.
9. hope this helps.

Regards, Tony

this problem is not caused by the switch, it is caused by a defective blower motor speed control resistor, the resistor is located near the blower motor.

check for fuses. If some other defective stuff that you replaced broke the fuse then you may need to repower the system by replacing the fuse or a relay.

As for the air, do you mean no blower for both heat function and A/C function? An Owners Manual would show location for fuse and relay for blower. A web-search with term like "2004 Mercury Grand Marquis fuse panel or
blower relay location" could help.

Last, do not know if blower resistor relay was known good quality. This part is tempermental. Sometimes takes tap from broom or snowbrush handle to wake it up. Sad part is that after warranty there is little benefit from a used to new part. Should have been a National recall on this part.

Its under the hood, just to the right and down of where the heater hoses connect on the firewall. It will have 4 wires going to it.

there is a resistor for the fan motor which works the lower speeds, you need to replace that, it is normally located near the blower motor, got 3-6 wires plugged in it

The resistor has two screws holding it onto the plastic case. The same case that houses the blower motor. The blower cools the resistor while its running.

The blower speed controller is located under the hood on the right or passenger side on the heater housing just to the side of the heater hoses near the very back of the right cylinder head.
Yes that would cause the concern you are having.