Question about Buick Century

3 Answers

I need a diagram for a heater - blower motor resistor on a 1998 buick century custom

Posted by on

  • 1 more comment 
  • Raymond Nicholson Sep 07, 2010

    After having removed the heater - blower motor resistor - I am not sure if there was 1 or 2 sets of wires that attach to the "Blower Motor Resistor"? Please help - on the new blower motor resistor there is a small 2 wire connector, but then there is a long terminal with 6 or 7 pins inside of it, and thats the one I'm not sure of and if I disconnected anything from or not?

    Thank You - Ray

  • Raymond Nicholson Sep 08, 2010

    I'm at a loss for this other wire (multi - pin) connector, so tomorrow I will have to get back under the dashboard to see if I missed / misplaced something (probable cause - I was working tired and not thinking clearly). Thanks again - RAY

    PS: I will keep you advised!

  • Raymond Nicholson Sep 08, 2010

    Can just the 2 wire plug-in connector wire make the blower motor resistor functional (speed switch to be able to select different speeds from low to high)? Next question - is there another wire connector that has to be plugged in to the resistor to make it work? Thank You - RAY

    Please note: I am not your everyday mechanic - sort of a do-it-yourself type.



3 Answers

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 20 achievements.


    An expert that got 10 achievements.


    An expert that got 5 achievements.

  • Buick Master
  • 17,970 Answers

The blower motor is a variable speed motor. The higher the voltage applied to the motor, the faster the speed. Depending on the HVAC (Heater Ventilation Air Conditioning) option installed in the vehicle, blower speed control could be through a set of resistors or through a solid-state blower motor control module.Battery voltage to the blower motor is supplied by the heater & A/C control by way of the blower resistor (or blower motor control module). At low and medium speeds, the voltage is stepped down by the blower motor resistors. At high speed, the blower motor relay is energized, removing the blower motor resistors from the circuit. Battery voltage is then applied directly to the blower motor through the relay. The motor will then run at maximum speed.

Several types of HVAC systems were available on these vehicles, from manual to fully automatic electronic control. The blower motor speed can be adjusted manually by pushing the fan switch up or down or automatically by placing the heater & A/C control in the AUTO mode.

In general, this system is reliable. Because so many of the control operations are electronic, special diagnostic equipment really should be used for system diagnostics and check-out. An authorized technician using a scan tool can most quickly locate HVAC problems.

I need a diagram for - 68f54ca.jpg

Fig. Typical behind-the-instrument panel view of HVAC related components. Depending on the HVAC option, not all components are used on all vehicles


Fig. Typical HVAC operation schematic
An inoperative blower motor could be caused by the following:

Blown fuse(s). The fuse should be replaced. There may be both a LOW BLOWER and HIGH BLOWER fuse. Some models may also call it the HVAC fuse. Even the RADIO fuse is used in some applications. Check them all. If a fuse is blown there may be a short to ground in one of the power supply circuits. Open Circuit. Check the circuit between the ignition switch and the blower motor, and the blower motor ground circuit. Repair as necessary. Faulty blower switch. A faulty blower switch should be replaced. Most heater blower circuits also include a blower motor relay (look in the underdash convenience center), as well as a blow motor resistor. These items should be checked especially if the blower runs in one or two speeds, but not all speeds selected.

The blower motor resistor is located on the back of the blower motor housing under the dash on the passenger side. It can be difficult to get at, but it is doable. Be ready with the ibuprofen the next day for your sore back.
Remove the cover panel from beneath the dash on the passenger side.
Unplug the power 'ribbon' wires leading to the resitor.
Unplug the wires that lead from the resitor to the blower motor housing. There are usually two, one black and one purple that share the same plug.
Remove the short hose that leads from the blower motor housing to the ventilation system ducts.
Remove the blower motor by removing the three hex screws that hold it in place.
Remove the resistor by removing the three hex screws that hold it in place. The resistor is right against the firewall so two of the screws are very difficult to reach. A slender flexible socket extension will make the job easier.
Attach the new resistor in place using the same hex screws. Only 1 or 2 of the original three are needed (the part is very light) if you do not feel like fighting with the ones next to the firewall.
Reatach the blower motor and reconnect the hose.
Plug the power cable wires back into the resitor and the wire from the resistor back into the blower motor.

Instead of hex screws mine were held in with 7/32 bolts. It was difficult, but easier than I had anticipated. I replaced two of the three bolts holding the resistor. The blower motor came with instructions saying that the plugs may have to be cut off of the resistor and the blower motor, then spliced together... I had to do this on mine.
I got everything back together and now the fan works on four of the five levels. It does not work on high.

I found on another site that said "high" uses a different circuit, with a separate fuse. I found the fuse panel on the passenger side of the dash when the door is open. The cover for the panel has all of the fuses mapped out, so it was easy to spot the 25 amp "Blower High Speed" fuse. I was very impressed to find the panel contained a fuse puller and replacement fuses. Mine was blown, I replaced it, and all is good with the world.

Hope helps.

Posted on Sep 08, 2010

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 10 achievements.


    An expert that got 5 achievements.


    An expert who has answered 1,000 questions.

  • Master
  • 1,016 Answers

I need a diagram for - 345c0ab.jpg

This will help you out.

Posted on Sep 08, 2010

  • Jason Maurirere
    Jason Maurirere Sep 08, 2010

    This may help you out then.

    Let me know if you need more information.



  • Level 3:

    An expert who has achieved level 3 by getting 1000 points


    An expert that got 20 achievements.


    An expert that got 10 achievements.


    An expert that got 5 achievements.

  • Master
  • 11,896 Answers

I need a diagram for - 4d0afe9.gifDoes this help?

Posted on Sep 07, 2010

  • Nate Stansfield
    Nate Stansfield Sep 07, 2010

    Two wire for power and a bigger pin set for selector and speed.

  • Nate Stansfield
    Nate Stansfield Sep 08, 2010

  • Locate
    the blower motor and look around the outside and close to the motor for
    a 2-by-3-inch plate held on by two or four small screws. There will be
    an electrical connector plugged into it with five or six wires,
    depending on the type of heating and air conditioning of control panel.

  • 2

    Test the resistor before replacing it. It is always
    recommended to test any electronic unit before replacing because there
    are a multitude of things that could cause the same symptoms. It only
    takes a few minutes and can qualify the assumption that a part is bad.
    It will save money to replace or repair the right part the first time.

  • 3

    Check the speeds by turning the fan conrol to all positions. Take note which fan speeds work and which speeds do not work. If the fan works only on one speed the blower motor resistor is very likely bad.

  • 4

    Check the fuses if the fan speeds do not work. The fuses for
    the interior heating and air conditioning fan are usually under the hood
    in the fuse and relay center. If the fuse looks good,
    then take it out and turn the ignition key on and use the volt meter
    set at 20 volts DC. Check to make sure that there is voltage to the
    fuse. If not, check for an open circuit to the fuse.

  • 5

    Check the relay to determine if there is power at the fuse.
    The relay should have two of the four terminals showing power. With the
    key on and the fan turned on, remove the relay and put it back in,
    listening for it to click. If it does not click, then replace the relay.

  • 6

    Check the voltage at the electrical connector on the blower
    motor resistor to see if the fuse and relay are good. Make sure that
    power is present at the connector with the key on and the fan switch on.
    There should be power at two terminals of the blower motor resistor. If
    only one terminal has power, replace the resistor. If two terminals
    have power, replace the blower motor itself. Remove the screws and
    unplug the connector to remove the blower motor resistor. Put the new
    one in its place by screwing it back in and plugging in the wiring


1 Suggested Answer

  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

a 6ya expert can help you resolve that issue over the phone in a minute or two.
best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.
the service is completely free and covers almost anything you can think of (from cars to computers, handyman, and even drones).
click here to download the app (for users in the US for now) and get all the help you need.

Posted on Jan 02, 2017

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

1 Answer

Where is the heater resistor on a 1996 buick century with a V6

You have to replace the blower motor. They don't use resistors anymore, each motor speed connects to a different spot on the motor windings to control the speed.

Jan 30, 2015 | 1996 Buick Century

1 Answer

1998 Buick Century w/ manual control, smelled burning odor and blower motor quit working. Control Module?

blower resistor is common to burn causeing smell. check with dealer, there may be a campain on this problem. if not. replace resistor and harness (pig tail) and blower motor..

Jan 21, 2013 | 1998 Buick Century

1 Answer

1998 buick century my heater and ac fan only work on high i'm told it's the blower relays where are they located

they are not relays its a blower motor resistor a one piece unit usually held in by two bolts and an electrical connector either under the passenger side dash or behind glove box

Aug 03, 2012 | 1990 Buick Century

2 Answers

98 century heater blower motor resistor location

look under the passenger side of the dash. There will be a plastic trim panel that will need to be removed. Once its out of the way you will see the blower motor. The resistor will be just to the drivers side of the blower motor.

Nov 15, 2011 | 1998 Buick Century

2 Answers

A/C Heater blower fan does not cycle through all speeds

Yes it is the blower Motors Resistor board. It is up behind the blower motor, just under the glove box. You have to remove the black KICK panel with its two "Push Pins" that will break too. There are 3 screws holding that resistor board in, the back two are a bear to get to. Good luck.

Feb 17, 2010 | 1998 Buick Century

1 Answer

Where is the blower motor switch?

the blower switch is in the dash in the control head the blower resistor is under the passenger side in the heater box

Jul 10, 2009 | 1998 Buick Century

1 Answer

2002 buick century heater resistor burning out

Sounds like something is drawing too much current for the resistor. Maybe blower motor going bad....

Apr 02, 2009 | 2002 Buick Century

1 Answer

Heater/AC Fan does not work in our 1998 Buick Century

Fan will be under dash on passengers side , Removing glove box might be needed, Gm also uses a blower resister ro control fan speeds. First check your fuse and then check and make sure your getting 12 volts to the terminal at the blower, You could have a blown fuse, a bad switch, or a bad resister , if your getting voltage to blower motor then most likely it will be the motor. These are not to difficult to change. I hope this helps, please be aware I can only guess at what the problem is from my past experience.

Dec 18, 2008 | 1998 Buick Century

3 Answers

Heater is dead

My 2000 century heater blower died,dont replace the fan motor until you check with a simple test light to see if the heater fan resistor is bad first,it's only 20 bucks to replace.Its located next to the fan housing up against the firewall.The wires from the fan switch go down to the resistor, check to see if switch has power then check for power down at the resistor,I'll bet its the resistor.There are three, I think five sixteenth screws to remove the resistor one is crammed up very tight on the firewall,you'll need a quarter inch drive extension with a wobbly socket to get that one against the firewall.

Dec 13, 2008 | 2000 Buick Century

Not finding what you are looking for?
Cars & Trucks Logo

Related Topics:

458 people viewed this question

Ask a Question

Usually answered in minutes!

Top Buick Experts


Level 3 Expert

76164 Answers

Colin Stickland
Colin Stickland

Level 3 Expert

22156 Answers

Jeff Turcotte
Jeff Turcotte

Level 3 Expert

8273 Answers

Are you a Buick Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides