A few weeks ago, our 2007 Mazda CX-9 Grand Touring model started doing something rather peculiar. When we turned-off the vehicle, the rear cabin fan would power-on at full-blast speed and continue to run for a few minutes. The blower would operate as expected when the vehicle was running; it was just this odd behavior when the ignition was turned-off.
A quick web search revealed that this seems to be a fairly common problem for Mazda CX-9 vehicles that were made between 2007 and 2009, and it's probably why you wound up finding this blog post.
There is a Technical Service Bulletin ("TSB") from Mazda concerning this problem: TSB 07-008/09, 2007-2009 CX-9 - BLOWER MOTOR STAYS ON AFTER KEY OFF. The TSB details the replacement of the blower relays, Mazda Part No. G115-67-730. There are two; one for the front (dashboard) fan and one for the rear (center console) fan.
This is not a very complex repair. However, that does not stop most Mazda dealerships from generating a handsome profit from the typical customer's repair fears. We have learned that other CX-9 owners have paid $150 or more to their dealer and lost a good part of their day to have this repair done. We would like to show you how to do the very same repair for about $30 or less in a matter of a few minutes.
ANYONE can perform this easy and inexpensive repair. You do not need any mechanical training or special tools. A simple pair of pliers are all that is needed. Just follow these three steps.
1) Confirm the problem. Okay, this seems kind of silly, but you should make certain that the problem we are explaining how to fix is really your vehicle's issue. When you turn-off the ignition on your 2007, 2008, or 2009 Mazda CX-9, does the front or rear cabin blower fan suddenly turn-on and then run for a few minutes? Problem confirmed. Proceed to the next step.
2) Purchase replacement relays. Surprisingly, there are a limited number of sources for these electrical components. What's even more surprising is that we found the best price from a Mazda dealership! If you live close to a dealer, phone their parts department and ask them for the price of Mazda Part No. G115-67-730 (Blower Motor Relay). If they want to charge you more than $15 each, consider making the purchase online.
We found the best price from a Mazda dealer in Arlington, Virginia; Rosenthal Mazda. They sell the relay for $12.68 each with reasonable UPS shipping costs. We ordered the parts late one evening and received them in the afternoon two days later. CLICK HERE to go to the part listing on this dealer's online store. Here is a photo of what you should have purchased and received.
You will need two relays; one for the front blower and one for the rear blower. Even if only one fan is acting-up, we recommend that you replace both. The parts are inexpensive and the repair is easy. Fix them both while you have the hood open!
We also found these blower motor relays for sale on eBay. However, they were used parts and we cannot recommend that you purchase a used part for this repair. When a brand new relay can be purchased for such a low price, why bother with a used part that is likely to fail quicker?
3) Replace the defective relays. This step is best demonstrated through a series of photos.
Open the hood to the engine compartment and look to the far-right, near the firewall (top right corner). There you will find the relay box; the plastic box circled in red in the photo above. Press the latch on the front of the box to release the cover and expose the parts within.
Take a look at the inside of the cover after you remove it. Here you will see the layout of the various relays that are housed within this box. Note the location of the two Blower Motor Relays (F. BLOWER RELAY and R. BLOWER RELAY).
Firmly grip the sides of the Blower Motor Relay with a pair of pliers and using a slight side-to-side motion, carefully loosen the relay and pull it from its socket. Repeat for the other Blower Motor Relay.
Insert the replacement relay into the vacant socket. Be certain to align the relay's tabs correctly. The relay's tabs are oriented such that the part will only fit when positioned correctly. If it does not seat with a firm push, make certain that it is properly aligned. Repeat for the other Blower Motor Relay.
Once both relays have been replaced, place the cover back on the box and make certain that it is secure. Close the engine compartment hood and wash your hands... you are done! Wasn't that easy?