Which is the Engine Cooling Fan Motor Relay?

Tiny
MING FENG
  • MEMBER
  • 2000 MAZDA MPV
  • 2.5L
  • 6 CYL
  • 2WD
  • AUTOMATIC
  • 150,000 MILES
Hi, early this year I posted questions regarding my vehicle listed above DX. Joe helped me to fix it. It had been ok for a while but recently it gave me trouble again. The engine area is super hot in the summer because the front fans stopped working. I have two questions. First, I Googled, and people said the first thing I should check is the cooling fan motor relay. I opened the two boxes under the hook. (See pictures) My user manual shows two 30A fuses are for the fans. I checked all four 30A pink fuses and they are all good. But the manual does not tell me which one is the relay. I attached the page from my manual and the fuse box pictures. Please help me to point out which is for the fans. Second, I looked at some YouTube videos that show people how to replace the control module. I looked around and could not find my car has a square shape control module. Then I found a product on Ebay called control unit (see picture). My question is if it is true my MPV does not have the module and instead I should use this control unit. Thank you very much for your kind help.
Wednesday, November 8th, 2023 AT 10:34 PM

45 Replies

Tiny
MING FENG
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Sorry. The pictures were not attached and I am adding them.
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Wednesday, November 8th, 2023 AT 10:36 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 50,003 POSTS
Sure, here is a guide to help test the relays and the cooling fan relay location in the images below:

https://www.2carpros.com/articles/how-to-check-an-electrical-relay-and-wiring-control-circuit

Check out the images below. Let us know how it goes.
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Thursday, November 9th, 2023 AT 9:20 AM
Tiny
MING FENG
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So, the small box is called relay box. Mine has three relays. I will test all of them. Will let you know. Thank you very much.
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Thursday, November 9th, 2023 AT 12:48 PM
Tiny
KEN L
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You are welcome, let me know how it goes please.
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Friday, November 10th, 2023 AT 9:26 AM
Tiny
MING FENG
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  • 82 POSTS
There are three relays on the side of a small relay box. Two black relays are for lights. So, I guess the green one must be it. It has five pins. I used the info (GA32 DC12V20A) on it to google and found Ebay has it. But the sellers said they do not know what part the relay is for. So, I just assumed it was for the cooling fan. There is no diagram on the side of the relay. I asked a electrician friend for help. He told me to do continuity between "NC" and "com" and use wire connected from the battery to touch the two "coil" to hear the click (see picture). All working! That means the relay is good. So, I need to go to the step to check. as I mentioned in my earlier post, there is an Ebay product https://www.ebay.com/itm/295093540289. I think I should find this part in the fan area in my car to check. (I do not have the square shape control module for the fan. Maybe I have and it's hidden somewhere.)
Thank you.
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Friday, November 10th, 2023 AT 6:55 PM
Tiny
KEN L
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The link doesn't not work? It looks like there are 7 cooling fan relays, please check the cooling fan wiring diagrams below to see how the system works and which relay controls which fan. Check out the images (below). Please let us know what happens.
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Saturday, November 11th, 2023 AT 9:57 AM
Tiny
MING FENG
  • MEMBER
  • 82 POSTS
Thank you. I will do some research. I thought there should be one or at most two relays. Seven relays for the two fans are a lot!
The link is
https://www.ebay.com/itm/295093540289 (without the ending period)
I searched "cooling fan control module for 2000 Mazda MPV" and nothing came out. The returned square module controls showing are for 2003-2006 Mazda MPV. That's the reason I think my 2000 MPV uses different kind of control like the link shows. But even for this one I have not been able to find where it is located. I will take off the battery to see if it is underneath. Thank you again.
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Saturday, November 11th, 2023 AT 3:12 PM
Tiny
MING FENG
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I am looking around and trying to find more relays and found one more small relay box close to the coolant tank. There are four relays inside (see picture) I will test them tomorrow.
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Saturday, November 11th, 2023 AT 8:39 PM
Tiny
MING FENG
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I showed the diagram to my electrician friend. He said there should be another relay box on the passenger side. But I looked around again. The small relay box close to the front and the coolant tank is the only one I can find. No other boxes. Another thing I can do is to take the battery and battery tray and some parts out so I can trace back the wire from the fan to other parts to see how they are connected.
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Sunday, November 12th, 2023 AT 8:27 PM
Tiny
KEN L
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There are two relay boxes which all seven relays are mounted. Does this vehicle have A/C? It shows the other relay box near the battery, is it there? Please upload an image, also have you tested the fan motors? Then go out.
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Monday, November 13th, 2023 AT 9:52 AM
Tiny
MING FENG
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It has A/C. The picture I uploaded earlier is near the battery. I took another picture (attached and you can see the battery) I will test the motor. I thought I should start the easy one and move to the hard one and I thought testing relay is easy. I did not know there were so many relays. So, I should forget relays for now and test the motor first. Thank you.
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Monday, November 13th, 2023 AT 9:31 PM
Tiny
KEN L
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Yep, the relay box with the green relays is for the cooling fan motor.

Please go over this guide and get back to us.
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Tuesday, November 14th, 2023 AT 7:28 AM
Tiny
MING FENG
  • MEMBER
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Hi, Ken,

Today I finally got time to test fans. Both are working. I traced the wire and thought I could find the control module (see picture I downloaded online for other MPVs) but cannot find any. The wires directly go to the relay box, the big, long rectangle box with yellow relay inside (see the picture I sent last time). I also noticed there is a cable between this big box and the small relay box (with the green relay). I do not know how the wires are connected inside.
It does not make sense. I saw YouTube videos and other years' MPVs always have the square shape fan control module. Both fans' wires plug into the module first and then go to the relay box. I believe there must be a thermostat inside the module, otherwise the fan will run all the time. I do not understand why my fan wires go to the relay box directly.
Thanks a lot,
Ming
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Sunday, December 10th, 2023 AT 6:38 PM
Tiny
KEN L
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Hi Ming,

I don't see the image below? The ECM controls the relay operation for the cooling fans. Can you confirm there is power at the engine fuse 30 amp and the fan fuses, also did you check the main system ground? Please check the images below.
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Monday, December 11th, 2023 AT 10:19 AM
Tiny
MING FENG
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Hi, Ken,

I stopped by my local Mazda dealer. A very nice gentleman in the parts department always helped me. He looked up the MPV by my VIN and said it does not have the fan control module. He suggested me to go back to look at the relays again and also the thermostat. I pulled out the 7 relays and checked each of them and they are all good. (I used the battery to connect two wires and touched the relay's two Coil pins and I can hear the click) Now I plan to check the thermostat (temp sensor). I ordered one from Walmart and it will come in a few days. I will compare the old one with the new one and will let you know.
Thank you,
Ming
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Saturday, December 16th, 2023 AT 2:32 PM
Tiny
MING FENG
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When I looked up the thermostat online, I found two types (see the two pictures attached). The circled marked one is what I bought, and I can find it in the MPV. But I do not know if I will also need the round one. I found a YouTube video for it. In order to replace this one, I will need to disconnect the coolant hose and it is inside. (https://www.youtube.com/watch?v=jcrpAGljZk4&t=39s)
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Saturday, December 16th, 2023 AT 2:49 PM
Tiny
MING FENG
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The weird thing that does not make sense to me for the round one (go-parts brand) is there are no wires connected to it. The part will go inside a hose, and I do not understand how it communicates with other parts like the fan.
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Saturday, December 16th, 2023 AT 2:52 PM
Tiny
MING FENG
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I found another YouTube video that explain the round thermostat ( https://www.youtube.com/watch?v=K-TocpZzIjY ). So, it looks like I bought the right thing. This round thermostat is for controlling the coolant flow based on the temp. My engine light is not on so the Engine itself is not overheated. I just need the front fan to run to blow hot air out.
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Saturday, December 16th, 2023 AT 2:59 PM
Tiny
KEN L
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We should connect a scanner to see what the engine temperature is reading.

Here is a guide to help:

https://www.2carpros.com/articles/checking-a-service-engine-soon-or-check-engine-light-on-or-flashing

Please go over this guide and get back to us.
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Monday, December 18th, 2023 AT 9:26 AM
Tiny
MING FENG
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Ken, Engine light is not on. The dashboard engine temperature indicator does not go up a lot meaning the engine itself is not too hot. Just when I open the front trunk, I cannot even touch the hood support rod because it is too hot. So, the problem must be the fan. I cannot hear the fan running either.
Thank you,
Ming.
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Monday, December 18th, 2023 AT 6:56 PM

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