05 mustang. No power to cooling fan

[buell-eyed-devil]

Cooling fan has not worked right since I got the car. You had to turn ac on for fan to work.Im in the middle of redoing ac and now fan won't work. Is there anywhere under hood I can get 12volts with key on to activate a relay?

 

[RonD]

Fuel injectors, IAC Valve and most solenoids get 12v with key on
Also O2 heaters and MAF sensor heater
MAF sensor heater is usually the easiest to tap
But no 12v in ACC

Check ECT sensor using an OBD reader to see if its showing correct temp after warm up, not sure if Ford used that in the Mustang but the electric fans were controlled by computer so it would be the most common way to activate it
And computer GROUNDED the cooling fan relay in the engine fuse box to activate it, either by temp or AC demand signal

If you pull the fan relay, and with key OFF one slot should test as 12volts, this is fans power voltage from its fuse
Key on, another slot should now test as 12volts, thats the relays coil voltage, the computer would ground the other end of coil to activate this relay, and send 12v to fan motor(s)

 

[buell-eyed-devil]

Car was in bad accident to passenger front and some not so special bodywork was performed. Already replaced gem module but no telling what other sins they have hidden. Where is mass sensor heater?

 

[pjtoledo]

MAF heater is part of the MAF unit.

 

[RonD]

MAF Sensor should have 6 wires in 2005, only one will have 12v key on, that's the heater power
On Rangers it was always a RED wire, but test it

 

[buell-eyed-devil]

It's red on mustang too. Works perfectly. Thanks all for info

 

[buell-eyed-devil]

Another little tidbit I found. Wouldn't come out of park, right blinker wouldn't work.....it was a fuse