Which is the Engine Cooling Fan Motor Relay?

Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,281 POSTS
Even if the check engine light is not on it could have pending codes that could help us.
Was this
answer
helpful?
Yes
No
Tuesday, December 19th, 2023 AT 12:33 PM
Tiny
MING FENG
  • MEMBER
  • 71 POSTS
Ken,

No engine light and no code. Maybe because I took off the battery a few days ago and have not driven it. Tomorrow the thermostat I bought online will come. I will take off and test the old one and replace it if needed.
BTW, how can I test the fan after installation? Just keep the car running for half an hour to see if the fan starts running. It's cold in my garage and it will take a while, I guess. Thank you.
Ming
Was this
answer
helpful?
Yes
No
Thursday, December 21st, 2023 AT 7:37 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,281 POSTS
You can test the system by turning the A/C on and waiting or about a minute, the fans should turn on. I am interested to see what happens with the new thermostat.
Was this
answer
helpful?
Yes
No
Friday, December 22nd, 2023 AT 9:58 AM
Tiny
MING FENG
  • MEMBER
  • 71 POSTS
Ken,

I just learn to fix simple car problems and my knowledge is so limited. I did not know the A/C could trigger the front fan. I should have done it earlier.
I replaced the fan thermostat. I started the car and turned on the A/C. The fan started to work almost immediately. After 30 seconds the fans stopped. Started again in 20-30 sec, stopped again. Is this normal? (Not run continuously)
I thought I have fixed the issue if the behavior is normal. But I was lost after I tested the old thermostat. Looks like it is good and behaves the same as the new one. (I learned from a YouTube video: put to ohms and touch the pin using a multimeter and use a hair dryer to heat the thermostat and I saw the reading going down.)
Really do not know what’s going on. In the summer it was super-hot in the front and my hand could not even touch the hood support rod.
I also bought the round thermostat (see attached picture). It can be installed inside the coolant tube. When the coolant temperature is high it will open and let the coolant to circulate. But I do not think I need it. Yesterday I drove the van for about half an hour. Then I touched the coolant tank and could feel the coolant inside is hot. That means the coolant was circulated. If the thermostat is bad and never open, the coolant should remain cold all the time. Am I correct?
Thank you and Merry Christmas,
Ming
Was this
answer
helpful?
Yes
No
Friday, December 22nd, 2023 AT 1:51 PM
Tiny
MING FENG
  • MEMBER
  • 71 POSTS
Before I replaced the thermostat, I should turn on the A/C to test the fan first.
Was this
answer
helpful?
Yes
No
Friday, December 22nd, 2023 AT 5:45 PM
Tiny
MING FENG
  • MEMBER
  • 71 POSTS
Ken, I was just curious. Since it takes me about 10 minutes to do it, I just replaced back the old thermostat. I turned on the A/C and watched. Exactly the same as what the new one does. The fan was on and off intermediately.
Thanks a lot.
Ming
Was this
answer
helpful?
Yes
No
Friday, December 22nd, 2023 AT 6:40 PM
Tiny
MING FENG
  • MEMBER
  • 71 POSTS
Does that mean my cooling fan system is good? In the summer the front was hot. That may be because of another different reason.
Was this
answer
helpful?
Yes
No
Friday, December 22nd, 2023 AT 6:42 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,281 POSTS
Merry Christmas to you as well, if the A/C system is on the fans should not cycle. When the A/C system is off the fans will cycle. Hope this helps.
Was this
answer
helpful?
Yes
No
Saturday, December 23rd, 2023 AT 10:44 AM
Tiny
MING FENG
  • MEMBER
  • 71 POSTS
Ken, not sure if I understand you. You said if the A/C system is on the fans should not cycle. But when I turn on the AC, the fan is running intermittently, on and off in a few sec, does that mean my system is running wrong?
Thank you,
Ming
Was this
answer
helpful?
Yes
No
Saturday, December 23rd, 2023 AT 12:48 PM
Tiny
MING FENG
  • MEMBER
  • 71 POSTS
You also said "When the A/C system is off the fans will cycle." If I turn off the AC, the fan will not run because the temp is not enough. In winter it's hard to test it. Maybe I have to drive a long time to find out.
Was this
answer
helpful?
Yes
No
Saturday, December 23rd, 2023 AT 12:50 PM
Tiny
MING FENG
  • MEMBER
  • 71 POSTS
My question is if it is normal that my fan cycles on and off for a short period of time when the AC is on. I searched online and saw it is actually a confusing question for other people. See this post.
Was this
answer
helpful?
Yes
No
Saturday, December 23rd, 2023 AT 2:47 PM
Tiny
MING FENG
  • MEMBER
  • 71 POSTS
The guy posted: " There is so much conflicting information, some people say the cycling is a bad sign and indicates a bigger issue within the AC system as a whole. This link here https://www.thetireman.com/Heating-and-Cooling.aspx claims "Some warning symptoms are: Electric engine cooling fan quickly cycles on and off" Other people say this is normal operation including some dealerships.

This website here https://www.aa1car.com/library/electric_cooling_fan.htm claims "so the fan does not come on until the engine reaches normal operating temperature (195 to 215 degrees). The fan will then cycle on and off as needed to maintain the coolant temperature"

So I guess it might be possible that this is normal? I have no clue. Two different people both with a 2011 and 2012 claim their fans do not cycle. ...
"
Was this
answer
helpful?
Yes
No
Saturday, December 23rd, 2023 AT 8:57 PM
Tiny
MING FENG
  • MEMBER
  • 71 POSTS
Merry Christmas Eve! I drove out car this afternoon for 40 minutes. When I stopped I kept the engine running and looked at the fan. No AC at that point of time. The fan cycled on and off. Looks like it is working, I guess. Not sure what's going to happen in the hot summer. Will see.
Was this
answer
helpful?
Yes
No
Sunday, December 24th, 2023 AT 2:48 PM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,281 POSTS
Glad you could get it fixed, thanks for letting us know. Please use 2CarPros anytime we are here to help.
Was this
answer
helpful?
Yes
No
Tuesday, December 26th, 2023 AT 10:05 AM
Tiny
MING FENG
  • MEMBER
  • 71 POSTS
Ken, hopefully it was really fixed. I will see what's going to happen in the summer when I use AC all the time.
This time I did not replace anything like thermostat, relays, fan. I guess what happened is somewhere the connection might be loose and it is fixed while I touched everywhere and plug on and off.
So far so good and it would not happen without your kind help in each step. I appreciate it. Will get back to you in the summer and let you know if further work needs to be done.
Thank you,
Ming
Was this
answer
helpful?
Yes
No
Tuesday, December 26th, 2023 AT 11:48 AM
Tiny
KEN L
  • MASTER CERTIFIED MECHANIC
  • 47,281 POSTS
You are welcome.
Was this
answer
helpful?
Yes
No
Wednesday, December 27th, 2023 AT 11:50 AM
Tiny
MING FENG
  • MEMBER
  • 71 POSTS
Ken, It's summer again. I drove the Mazda MPV 2000 today. I used the AC. Looks like the same problem is still there. I drove half an hour and opened the front hood and felt it is very hot. Even the hood support rod is too hot to touch, I saw the fan was running. I touched the coolant tank and it is also very hot, meaning the coolant was Circulating. What could cause the unusual high temperature in the front engine area? Thanks a lot,
Ming
Was this
answer
helpful?
Yes
No
Thursday, May 9th, 2024 AT 2:48 PM
Tiny
MING FENG
  • MEMBER
  • 71 POSTS
I found this online: symptoms of overheating, which can include:

Steam (which can look like smoke) coming from under the car hood.
An engine temperature gauge on your dashboard that spikes to "H" or into the red. (Engine temperature gauge symbols vary, so consult your owner's manual.)
A strange smell coming from the engine area. For example, leaking coolant can smell sweet while leaking oil might smell more burnt.

I do not have any of them. I just opened the front hood and felt it's hot based on my experience. I think I can open the front hood and the one inch space will blow in air when I drive on highway.
Was this
answer
helpful?
Yes
No
Thursday, May 9th, 2024 AT 3:38 PM
Tiny
STEVE W.
  • MECHANIC
  • 13,414 POSTS
It sounds normal really. Modern cars tend to run very hot. Coolant temperatures well over 200 are normal while running. If the light or gauge isn't showing hot then it may be normal. What I would do is get a non contact thermometer and check the various parts of the system with that to see the real temperatures. I would suggest not driving with the hood on the secondary catch, I have seen the results of that and it wasn't a good thing.
Was this
answer
helpful?
Yes
No
Friday, May 10th, 2024 AT 6:34 PM
Tiny
MING FENG
  • MEMBER
  • 71 POSTS
Hi, Steve,

You said " would suggest not driving with the hood on the secondary catch, I have seen."
Thank you for letting me know that. I thought it's safe and I will drive 3 hours on the highway tomorrow and I was planning to do it. What can happen? (The wind cannot blow it up, I guess.)
As for the temperature, maybe it's normal but I don't remember it is so hot before. The hood support rod was always quite warm after driving for a while but not that hot.
Thank you again,
Ming
Was this
answer
helpful?
Yes
No
Friday, May 10th, 2024 AT 6:52 PM

Please login or register to post a reply.

Sponsored links