 radiator fans always on |
 Nov 27, 2012 - 1:22 PM
|
 
|
|
Enthusiast  Joined Jun 23, '10 From Pawtucket, RI Currently Offline Reputation: 2 (100%)  |
so like the title says I've been having this issue ever since having to put back the 5sfe motor into my car. Both radiator and A/C fan start to run the moment i turn the key to the "on" position. i tried unpluging both coolant temp sensors but they continue to run, my relays for the fans are working correctly so at this point im confused and exhuasted, the only thing i can think of is the ecu took a dump on me and is telling the fans to stay on all the time BUT i dont have another ecu to swap it with and i dont want to spend the money to do so and i end up being wrong. so has anyone else ran into this problem or have any suggestions for me. i really wanna fix this cause im sure its the reason my car runs like **** in cold start and takes forever to warm up properly.
-------------------- I only want to be faster than the guy next to me.
|
 |
Replies
(1 - 9)
|
Nov 27, 2012 - 1:57 PM
|
|
|
Enthusiast Joined Dec 8, '03 From Lancaster CA Currently Offline Reputation: 6 (100%) |
this happens if the plug at the bottom of the radiator is unplugged. double check its connection
-------------------- 2001 Celica GT-S Turbo
1997 Supra TT 6speed 1997 Celica 3MZ/1MZ swap 1990 Celica All-Trac |
|
Nov 27, 2012 - 2:05 PM
|
|
|
Enthusiast Joined Jun 23, '10 From Pawtucket, RI Currently Offline Reputation: 2 (100%) |
QUOTE (Smaay @ Nov 27, 2012 - 1:57 PM)  this happens if the plug at the bottom of the radiator is unplugged. double check its connection are you talking about the plug that go to the ECT on the radiator? -------------------- I only want to be faster than the guy next to me.
|
|
Nov 27, 2012 - 3:41 PM
|
|
 Enthusiast Joined Jan 3, '06 From The Netherlands Currently Offline Reputation: 6 (100%) |
Smaay, isn't it so that if it's disconnected, the fans wont turn on at all? I believe in order to run the fans constantly you had to bridge the connector. In that case I would say the sensor is stuck in closed-loop
-------------------- JDM ST205
|
|
Nov 27, 2012 - 3:53 PM
|
|
|
Enthusiast Joined Mar 3, '05 From Richmond, B.C. Currently Offline Reputation: 0 (0%) |
If the fan's power is disconnected, then yes it won't run. If the water temperature fan switch is disconnected, or faulty, the fan will run all the time -- it's Toyota redundency.
|
|
Nov 27, 2012 - 5:12 PM
|
|
|
Enthusiast Joined Dec 8, '03 From Lancaster CA Currently Offline Reputation: 6 (100%) |
QUOTE (Galcobar @ Nov 27, 2012 - 12:53 PM) If the fan's power is disconnected, then yes it won't run. If the water temperature fan switch is disconnected, or faulty, the fan will run all the time -- it's Toyota redundency. ^^ correct, its not seeing the sensor so it turns the fans on. -------------------- 2001 Celica GT-S Turbo
1997 Supra TT 6speed 1997 Celica 3MZ/1MZ swap 1990 Celica All-Trac |
|
Nov 28, 2012 - 7:25 AM
|
|
|
Enthusiast Joined Jun 23, '10 From Pawtucket, RI Currently Offline Reputation: 2 (100%) |
QUOTE (Smaay @ Nov 27, 2012 - 6:12 PM) QUOTE (Galcobar @ Nov 27, 2012 - 12:53 PM) If the fan's power is disconnected, then yes it won't run. If the water temperature fan switch is disconnected, or faulty, the fan will run all the time -- it's Toyota redundency. ^^ correct, its not seeing the sensor so it turns the fans on. so should i try to change out the switch thats on the bottom corner of the radiator? -------------------- I only want to be faster than the guy next to me.
|
|
Nov 28, 2012 - 9:54 AM
|
|
|
Enthusiast Joined Dec 8, '03 From Lancaster CA Currently Offline Reputation: 6 (100%) |
its not a switch, its a sensor. and yes thats a good start
-------------------- 2001 Celica GT-S Turbo
1997 Supra TT 6speed 1997 Celica 3MZ/1MZ swap 1990 Celica All-Trac |
|
Nov 29, 2012 - 4:00 AM
|
|
|
Enthusiast Joined Mar 3, '05 From Richmond, B.C. Currently Offline Reputation: 0 (0%) |
Toyota refers to it as a switch, specifically water temperature switch because it opens and closes the circuit itself based upon temperature (93C) rather than signalling something else. It's not a switch that we operate, certainly.
You can easily test the water temperature switch with a pot of water. Below 93C, there should be no continuity between the terminals of the switch. This keeps the fan power circuit open and the fans off. Above 93C, the switch should close, establishing continuity between the terminals and running the fan. |
|
Nov 29, 2012 - 8:04 PM
|
|
 Enthusiast Joined Oct 25, '11 From Tbilisi Currently Offline Reputation: 3 (100%) |
Galcobar is right.
I had the same problem. Water temperature switch was broken. Replaced it and now it's working fine. -------------------- |
 |
1 User(s) are reading this topic (1 Guests and 0 Anonymous Users)
0 Members:
| Lo-Fi Version | Time is now: July 18th, 2025 - 4:56 AM |