gen 6 celica rad fans not coming on Options

[tumber120]

hi was wondering if any one may be able to help i have a gen 6 celica 205 gt
basically it keeps bursting its radiator. The fans work but are not cutting in when the car is up to temp the temp gauge reads normal. Its had a new rad, rad cap, thermostat, and fan relays. I would be over the moon if any one has any ideas as i am at my wits end with it.

[Galcobar]

Sounds like the water temperature switch (plugged into the radiator at the bottom) is out of order.

The cooling fans are wired to run constantly, as a fail-safe measure. The water temperature switch (it looks like a standard water temp sensor but has a switch built in) actually turns the fans off if the coolant is below 93C. Unplugging the switch with the ignition turned to ON should result in the fans spinning. If the switch is reading the coolant as cold, even when it's hot, the fans won't turn on.

If your fans run with the temperature switch disconnected, then the wiring is in order. If not, you're looking at a short between the cooling fan relay and the temperature switch, or a faulty relay. You state the fans run, so we'll start with the assumption that the new relays you mention are working, and go after the fan switch.

You can determine if the the fan's water temperature switch needs to be replaced with a pot of water and a continuity tester. There should be continuity between the switch's terminals if the water is below 83C, and no continuity if the water is above 93C.