ECU & Electronics Discuss electronics and related components within.

radiator fans turn on with ignition

  #1  
Old 08-08-2016, 09:52 PM
Junior Member
Thread Starter
Join Date: Aug 2016
Posts: 4
Default radiator fans turn on with ignition

hi, i have a toyota camry 1998 4cyl. (5s-fe engine).

when i turn the key to the "on position" the both radiator fans turn on while the a/c is off. i have checked fan relays 1,2,3 and they are all good. voltage tested the ect sensor connector (reads 5v).

could it be a faulty fan switch in the radiator? i checked the voltage and it reads 12v from the connector. what should i do from here to solve this issue?
 
  #2  
Old 08-09-2016, 10:03 AM
Super Moderator
Join Date: Jan 2008
Location: PTW
Posts: 11,742
Default

The fan switch is CLOSED when the coolant temp is below the set point needed to turn on the fans.

If the switch fails in the OPEN position or the harness plug to the switch is disconnected or there is an open wiring fault to the switch. The fans will turn on.

Check for an open switch or wiring issues.
 
  #3  
Old 08-11-2016, 12:23 AM
Junior Member
Thread Starter
Join Date: Aug 2016
Posts: 4
Default

thanks i will do that.
 
  #4  
Old 08-11-2016, 01:00 AM
Junior Member
Thread Starter
Join Date: Aug 2016
Posts: 4
Default

Originally Posted by toyomoho View Post
The fan switch is CLOSED when the coolant temp is below the set point needed to turn on the fans.

If the switch fails in the OPEN position or the harness plug to the switch is disconnected or there is an open wiring fault to the switch. The fans will turn on.

Check for an open switch or wiring issues.
how much voltage should be flowing to the cooling fan switch connector when car is on? should it read 12v?
 
  #5  
Old 08-11-2016, 09:51 PM
Super Moderator
Join Date: Jan 2008
Location: PTW
Posts: 11,742
Default

Use an ohm meter on the switch. The switch should be closed.

The switch will always have 12V if the ign switch is on.
 
  #6  
Old 08-15-2016, 02:46 AM
Junior Member
Thread Starter
Join Date: Aug 2016
Posts: 4
Default

OK i replaced the cooling fan switch, i just plugged it in while leaving the old one in the radiator, a/c was turned off and both cooling fans connected and they both still turn active when the key is in the "on" position, car was dead cold.

Did i do something wrong or could the problem lay else where?

i tested the new switch and it has like only 0.03-4 ohm of resistance so its good.
 
  #7  
Old 08-15-2016, 11:27 AM
Super Moderator
Join Date: Jan 2008
Location: PTW
Posts: 11,742
Default

The temp switch plugged in or not makes no difference in the fans being on or off?

Is there any change in fan speed (faster/slower) when plugged into the switch or not?

You checked the relays to make sure the relay power switch turned off when the solenoid is not powered?
 
Related Topics
Thread
Thread Starter
Forum
Replies
Last Post
egarci10
Engine & Internal
2
07-08-2011 09:52 AM
justinw
Engine & Internal
0
07-11-2010 06:44 PM
aarong34
General Tech
0
08-16-2009 09:22 PM
fleshbone
Headers, Intake, & Exhaust
1
05-15-2009 02:46 AM
KEVAUG
General Tech
19
02-28-2008 07:59 AM


Thread Tools
Search this Thread
Quick Reply: radiator fans turn on with ignition


Contact Us - Archive - Advertising - Cookie Policy - Privacy Statement - Terms of Service

© 2019 MH Sub I, LLC dba Internet Brands

We are a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for us to earn fees by linking to Amazon.com and affiliated sites.