Front fan issue / on high speed all the time
#1
Front fan issue / on high speed all the time
I own a 2004 Chrysler Pacifica, and the front fan stopped working. I replaced the front blower motor resistor with three (3) new ones. I know the man at the local AutoZone who took them back. Replacing this unit with a new one did not fixed the problem.
What I discovered if I run a wire between the negatives of the blower motor resistor (black to black/orange wires) the fan stay on high speed and nothing on the control unit (changing the fan speeds or turning the unit on/off) changes the fan speed from being on high.
Do you know what the issue is with my car? I am clueless at this point.
What I discovered if I run a wire between the negatives of the blower motor resistor (black to black/orange wires) the fan stay on high speed and nothing on the control unit (changing the fan speeds or turning the unit on/off) changes the fan speed from being on high.
Do you know what the issue is with my car? I am clueless at this point.
#3
By testing this
I will test power and grounds at the front blower motor resistor and fan motor and this weekend? By testing this, what am I trying to narrow down to be my problem – i.e. a bad fan motor or something else?
#6
Hi.
If you have the auto-climate control, fan speed is not controlled with a simple resistor pack.
It is a pulse-width modulated 'Blower Control Module' like this:
CARAVAN TOWN COUNTRY BLOWER MOTOR RESISTOR MODULE MOPAR | eBay
The typical failure mode is that the fan runs uncontrollably at high speed regardless of the the manual setting - you'll see the 'speed bars' on the display change, but the fan will run full speed.
Remove/replace procedure is the same as the resistor pack.
If you have the auto-climate control, fan speed is not controlled with a simple resistor pack.
It is a pulse-width modulated 'Blower Control Module' like this:
CARAVAN TOWN COUNTRY BLOWER MOTOR RESISTOR MODULE MOPAR | eBay
The typical failure mode is that the fan runs uncontrollably at high speed regardless of the the manual setting - you'll see the 'speed bars' on the display change, but the fan will run full speed.
Remove/replace procedure is the same as the resistor pack.
#7
And...the failure is usually the MOSFET power transistor in the module. If you are handy with a soldering iron and so inclined, look up online or visit your local electronics supply house and buy a Fairchild N-channel MOSFET part number HUF75343P3.
The MOSFET will cost you ~$2.00-$3.00
The entire module is $50-$100.
I have repaired several with good results and no further issues.
The MOSFET will cost you ~$2.00-$3.00
The entire module is $50-$100.
I have repaired several with good results and no further issues.
#8
Goldsmi -
I purchase and tried three (3) new blower motor resistors, and "the typical failure mode of the fan running uncontrollably at high speed regardless of the the manual setting - l do see the 'speed bars' on the display change, but the fan will run full speed." Still happens.
The only twist to make the typical failure happen is that I need to run a wire between the negatives of the blower motor resistor (black to black/orange wires). If I do not run the wire, the fan does not blow at all.
I purchase and tried three (3) new blower motor resistors, and "the typical failure mode of the fan running uncontrollably at high speed regardless of the the manual setting - l do see the 'speed bars' on the display change, but the fan will run full speed." Still happens.
The only twist to make the typical failure happen is that I need to run a wire between the negatives of the blower motor resistor (black to black/orange wires). If I do not run the wire, the fan does not blow at all.
#10
a/c Heater blower control switch
The part I replaced three times is the a/c Heater blower control switch. Below is the link.
Duralast/A/C Heater Blower Control Switch (JA1623) | 2004 Chrysler Pacifica AWD 6 Cylinders 4 3.5L SFI SOHC | AutoZone.com_
I do have automatic climate control with dual control.
The only way for me to make my fan run on high and have the typical failure you described is to run a seperate wire between the negative (black to black & orange) of this switch.
Not sure why the grounds are not connect between the two plug in on this unit.
Duralast/A/C Heater Blower Control Switch (JA1623) | 2004 Chrysler Pacifica AWD 6 Cylinders 4 3.5L SFI SOHC | AutoZone.com_
I do have automatic climate control with dual control.
The only way for me to make my fan run on high and have the typical failure you described is to run a seperate wire between the negative (black to black & orange) of this switch.
Not sure why the grounds are not connect between the two plug in on this unit.