Radiator fans on on a stone cold car
#1
Thread Starter
Radiator fans on on a stone cold car
Turned the car on this morning after it sat for 3 days.
Radiator fans started running upon startup. This has happened before when the car "burped" after replacing the radiator. In the past a top off of about 1/8 cup of coolant/water mixture would trip the sensor in the expansion tank, and they would turn off. Tried this trick this morning and the fans did NOT turn off.
The radiator and the expansion tank were replaced recently, and no noticeable leaks have been detected.
Bad switch in the expansion tank?
What do you guys think? Thanks!
Brian
Radiator fans started running upon startup. This has happened before when the car "burped" after replacing the radiator. In the past a top off of about 1/8 cup of coolant/water mixture would trip the sensor in the expansion tank, and they would turn off. Tried this trick this morning and the fans did NOT turn off.
The radiator and the expansion tank were replaced recently, and no noticeable leaks have been detected.
Bad switch in the expansion tank?
What do you guys think? Thanks!
Brian
#2
Rennlist Member
A/C button on? When I was testing my fans a couple of weeks ago, I noticed that one of them (only one is getting signal) came on when I depressed the A/C button right after startup, even though the engine was cold.
Hmmm... maybe my fan control module is my problem...
Hmmm... maybe my fan control module is my problem...
#4
Rennlist Member
".... In the past a top off of about 1/8 cup of coolant/water mixture would trip the sensor in the expansion tank, and they would turn off. ..."
I didn't know that the switch in the expansion tank had anything to do w/ the Fans, thought it was only a fluid level switch?
I didn't know that the switch in the expansion tank had anything to do w/ the Fans, thought it was only a fluid level switch?
#5
Nordschleife Master
Turned the car on this morning after it sat for 3 days.
Radiator fans started running upon startup. This has happened before when the car "burped" after replacing the radiator. In the past a top off of about 1/8 cup of coolant/water mixture would trip the sensor in the expansion tank, and they would turn off. Tried this trick this morning and the fans did NOT turn off.
The radiator and the expansion tank were replaced recently, and no noticeable leaks have been detected.
Bad switch in the expansion tank?
What do you guys think? Thanks!
Brian
Radiator fans started running upon startup. This has happened before when the car "burped" after replacing the radiator. In the past a top off of about 1/8 cup of coolant/water mixture would trip the sensor in the expansion tank, and they would turn off. Tried this trick this morning and the fans did NOT turn off.
The radiator and the expansion tank were replaced recently, and no noticeable leaks have been detected.
Bad switch in the expansion tank?
What do you guys think? Thanks!
Brian
Start with the troubleshooting section at the end of Vol. 1 in the WSM. There are checks for each sensor. Also have you been working anywhere else in the car ? Recently a thread where a guy working on a window problem was playing at the connections to his window controller - in one post he turns his fans on.
#6
Thread Starter
AC button is off. I know about that one.
Recent service included new radiator and expansion tank, and rear brake rotors and pads. It was running ok for a few weeks since those services were completed without problems, now this.
I'll check the WSM tonight.
Recent service included new radiator and expansion tank, and rear brake rotors and pads. It was running ok for a few weeks since those services were completed without problems, now this.
I'll check the WSM tonight.
#7
Addict
Lifetime Rennlist
Member
Lifetime Rennlist
Member
Trending Topics
#8
Nordschleife Master
#10
Nordschleife Master
^ Test function of all the sensor/switches from inside the car without getting dirty. Test at fan controller under front seat /passenger side panel. See WSM Vol. 1
#11
Rennlist Member
Join Date: Oct 2005
Location: Gatineau, Québec, Canada
Posts: 5,136
Received 1,207 Likes
on
467 Posts
This same situation - fans on at start-up - happened to me this summer.
After a little bit of search under the hood, I notice the slider was on the recirculation position.
Easy fix for sure!
#12
Thread Starter
Just a follow up.
AC button works and is off.
It was a bad relay IV or "ignition relay X". Second one from the left on the top row of relays.
Replaced with a new one and it works great!
AC button works and is off.
It was a bad relay IV or "ignition relay X". Second one from the left on the top row of relays.
Replaced with a new one and it works great!
#13
Nordschleife Master