Radiator Fans staying on full blast

[kris_pran]

My stock radiator started to leak from the crimped area so i replaced it with an alloy radiator of trademe. Now it seems that the cooling fans are working twice as much as it used too when the stock radiator was in place.

When it reach's a certain temp, the fans stay on until i turn the car off.

Has anyone else come across this problem?

[boon]

Running the fans flat-out all the time is a fail-safe in the ECU if it can't read certain parameters such as coolant temp. I can't remember if these cars do fan rpm sensing but I know that some will run the fans full tilt if they can't read the fan speed.

[kris_pran]

It can definitely read coolant temps, My logger shows the ecu reading coolant temps.

[Rosssub]

Try disconnecting the battery for a while (ECU reset), also is the coolant system %100 bled? Only time I get both fans on is with temp sensor disconnected/fault like Boon said.

[kris_pran]

All i did was install rad, fill up with fluid, start car, open bleed valve, fill fluid till its full. (Car was parked on a steep angle)

Car drives fine and temps are normal.

[Joker]

is the temp sensor plugged in?

[kris_pran]

Noob reply but is that the one underneath the alternator? If so then yes its plugged in and ive never touched it before. The only two plugs that removed were the fan connections and since have been fitted back.

[Rosssub]

Yip that's the coolant temp sensor. Guessing no CEL at all after a short drive in test mode?

Edit: Only other reason I can come up with is that it's not bled completely and is actually getting up to a temp when both fans would engage.

Have you had it up to running temp/driving (heater on), then rechecked the coolant levels?

Edited August 5, 2014 by Rosssub

[kris_pran]

No cel but i didnt drive it in test mode.

Yes i have had it up to the running temp and heater was on full blast, the coolant is full.

[Rosssub]

Put it into test mode and go for a drive until the CEL starts flashing, see if #21 comes up.