AC fan stays on at all times?

Caleb Mueller · May 31, 2017

Hello, I have a 1988 Toyota Celica Alltrac (4WD Turbo) and ever since I've owned the car, the front secondary fan (mounted on the front of the radiator and blows into the engine bay) stays on all the time at low speed when the key is turned to the start position (engine off and engine on). Also today my radiator fan 30 amp fuse blew and my car overheated. I replaced the fuse with my 60 amp anti-lock brakes fuse to get it home and it didn't overheat. We have checked all the relays and they seem to be working fine. What is going on??

telectrix · May 31, 2017

most common cause of a fan running when it should not is a shorted out temp sensor, usually mounted on the rad. check it with a ohm meter. should read open circuit when cold.

Marvo · May 31, 2017

It could be a temp sensor or maybe a pressure sensor on the high side of the system. Either way test them as Tel suggests and look carefully at the wiring to see if someone has deliberately shorted the sensor as a temporary repair in the past.

Specialist · Jun 1, 2017

Could also be that the fan relay contacts have welded together with age.
Really difficult to tell without actually having the car in front of you.

static zap · Jun 6, 2017

Does the AC actually work , may have someting to do with how it was disabled . (no Toyota experience )

Wilko · Jun 6, 2017

Some systems have a fan running anytime the ac is on ...

Auto Technician · Jun 14, 2017

The best place to start is the Toyota technical information unless you are not experienced in diagnostics!
Your post suggests that there maybe two electrical fans fitted, one for the A/C system and one for the cooling system, and when the A/C system fan is not operating the cooling system overheats!
Your post comes across to me like you have more than one problem. If you intend trying to resolve the problem(s) yourself, have you got any diagnostic equipment to carryout an investigation, can you check and read fault code data!
Can you read live data!
Difficult to steer you in the correct direction without more detailed information!