fan is always on when car is running?(cooling radiator)
10-29-12, 11:11 AM
#17
It gotta be the fan switch..
If the cables are cut then the ECu will sense the car is hot all the time cuz there is no signal and to prevent the engine to go back the fan will keep going..
The only thing that controls the fan is that..
was ur car previously in an accident?
did u replace the radiator before?
Also, make sure you have the correct fan switch..
I thought there are all the same so i tried the is300 with my gs430 and they didnt work the same...
If the cables are cut then the ECu will sense the car is hot all the time cuz there is no signal and to prevent the engine to go back the fan will keep going..
The only thing that controls the fan is that..
was ur car previously in an accident?
did u replace the radiator before?
Also, make sure you have the correct fan switch..
I thought there are all the same so i tried the is300 with my gs430 and they didnt work the same...
Last edited by ZhiuPei; 10-29-12 at 11:17 AM.
10-30-12, 08:13 PM
#18
It gotta be the fan switch..
If the cables are cut then the ECu will sense the car is hot all the time cuz there is no signal and to prevent the engine to go back the fan will keep going..
The only thing that controls the fan is that..
was ur car previously in an accident?
did u replace the radiator before?
Also, make sure you have the correct fan switch..
I thought there are all the same so i tried the is300 with my gs430 and they didnt work the same...
If the cables are cut then the ECu will sense the car is hot all the time cuz there is no signal and to prevent the engine to go back the fan will keep going..
The only thing that controls the fan is that..
was ur car previously in an accident?
did u replace the radiator before?
Also, make sure you have the correct fan switch..
I thought there are all the same so i tried the is300 with my gs430 and they didnt work the same...
10-31-12, 04:49 PM
#20
Here some update. Last night I went to my car and started the car. The fan was still on. I lightly tapped the a/c pressure switch with my small flashlight and the fan stopped. I think there is some problem with my pressure switch. Now, the car functions like normal and fan turns on when it hits normal temp. the problem last time when i turned on my a/c, The fan stayed on after i turned off my a/c.
So guys! Check your a/c pressure switch if everything checks out with the relays and sensors!
I will keep you guys posted if it happens again. Thanks guys!
So guys! Check your a/c pressure switch if everything checks out with the relays and sensors!
I will keep you guys posted if it happens again. Thanks guys!
08-22-13, 02:55 PM
#23
Driver School Candidate
Join Date: Jan 2012
Location: NM
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
Where is the A/C pressure switch? I have a similar issue in my 98 GS400. The number one fan (drivers side) is on at running temp, but the number two fan NEVER turns on. I replaced the thermostat, and installed the water temp switch on the radiator (there wasn't one there previously), and the fans/shroud/coolant overflow setup cause the original number two fan motor broke and I got a sweet deal online for the whole setup. Still no number two fan. When is the number two fan supposed to engage? Which relay is for the number two fan, cause there are 3 fan relays. My GS overheats now, im pretty sure cause of the second fan not turning on. The temp gauge reads that its at running temp but when ive been driving for 15mins or so I hear the coolant boiling. Please help.
08-24-13, 02:49 PM
#26
Driver School Candidate
Join Date: Jan 2012
Location: NM
Posts: 6
Likes: 0
Received 0 Likes
on
0 Posts
So i looked up on All Data where the locations are for the relays to the fans. There's relays on both sides of the engine bay. The 3 I was referencing before are on the drivers side...but there are a few more on the passenger side by the battery box. Sure enough one of those was fried...a 30amp for the CDS fan. I replaced it. Now both fans come on and have high/low speeds which is awesome cause my car doesn't overheat, nor does my coolant boil over...but ONLY when the a/c is on. Otherwise neither fan engages at all...so as long as i drive with the a/c on I'm squared away. But I'm not satisfied with this. Could the a/c pressure switch be why neither fan turns on UNTIL the a/c is on? And where is it exactly? All Data isn't recognizing my searching it by "Air conditioning pressure switch". Anyone have a pic of where it is at?
08-24-13, 06:02 PM
#27
Driver School Candidate
Join Date: Feb 2012
Location: Florida
Posts: 17
Likes: 0
Received 0 Likes
on
0 Posts
The radiator fan has it's own temperature switch. It turns the fan on when the coolant reaches a certain temperature. It is located near the thermostat on most cars.
01-14-14, 02:51 PM
#28
Driver School Candidate
Join Date: Nov 2005
Location: ky
Posts: 41
Likes: 0
Received 0 Likes
on
0 Posts
I am also having the same issue on my 99 gs300. here is all i know i disconnected the rad. temp sensor and started the car and the fans constantly stay on. now i took the no. 1 and no. 2 relay out and both fans stop. so i went to the auto parts store and replace the no. 1 relay with the new replacement and still does the same thing it stays on. could not replace the no. 2 relay had to special order that. what else could be the issue? the pass. side fan runs higher than the driver side i dunno if their is something causing that as well. I definitely need some good insight to fix this issue thanks.
01-15-14, 01:49 PM
#29
Driver
Join Date: Jan 2014
Location: florida
Posts: 135
Likes: 0
Received 0 Likes
on
0 Posts
i would have thought your fan clutch was stuck.....go in your hood and you should be able to spin the fan freely when the car is off.if it dosent spin then the clutch is stuck.
