A/C Fan not coming on
#1
A/C Fan not coming on
My A/C cooling fan is not coming on in my 2003 Disco II how do I check to see if it is the Fuse or switch or fan unit it self?
Should it come on everytime A/C is on?
I am in Arizona so it is hot all the time.
A/C Air is getting cold.
Any help would be great.
Thanks,
Duke
Should it come on everytime A/C is on?
I am in Arizona so it is hot all the time.
A/C Air is getting cold.
Any help would be great.
Thanks,
Duke
#2
The a/c fan will not come on until the engine temp is normal and the outside air is over 75*F?
With the key off try and turn the fan by hand, if you cannot spin the fan blades by hand the fan is seized.
If you can then you need to check the fuse.
It is common for the fan motor to seize and blow the fan fuse.
With the key off try and turn the fan by hand, if you cannot spin the fan blades by hand the fan is seized.
If you can then you need to check the fuse.
It is common for the fan motor to seize and blow the fan fuse.
#3
Spin fan with truck off, it should freewheel. Use small screwdriver, etc., to get through the shroud. If it is stiff to turn, it has probably blown the fuse, and won't be coming on. Replacing the fuse will be sort lived, as fan heats up bearing friction increases. Fuse 5 in underhood box is connected by relay to run fan. Relay is switched on by ECU when ECU decides it is time for fan.
Those times from the shop manual are:
On a D1 they are on (two of them) whenever AC is on. On the D2, as above, controlled by the brain.
Those times from the shop manual are:
Electric cooling fan switching points:
For A/C system:
⇒ On When vehicle speed is 50 mph (80 km/h) or less and ambient
temperature is 28 °C (82 °F) or more
⇒ Off When vehicle speed increases to (62.5 mph (100 km/h) or ambient
temperature decreases to 25 °C (77 °F)
For engine cooling during normal running:
⇒ On 100 °C (212 °F)
⇒ Off 94.5 °C (202 °F)
For engine cooling at ignition off (to counteract heat
soak):
⇒ On If, within 10 seconds of ignition off, intake air temperature is 60 °C (140
°F) or more and engine coolant temperature is 110 °C (230 °F) or more
⇒ Off After 10 minutes or if engine coolant temperature decreases to 100 °C
(212 °F)For A/C system:
⇒ On When vehicle speed is 50 mph (80 km/h) or less and ambient
temperature is 28 °C (82 °F) or more
⇒ Off When vehicle speed increases to (62.5 mph (100 km/h) or ambient
temperature decreases to 25 °C (77 °F)
For engine cooling during normal running:
⇒ On 100 °C (212 °F)
⇒ Off 94.5 °C (202 °F)
For engine cooling at ignition off (to counteract heat
soak):
⇒ On If, within 10 seconds of ignition off, intake air temperature is 60 °C (140
°F) or more and engine coolant temperature is 110 °C (230 °F) or more
⇒ Off After 10 minutes or if engine coolant temperature decreases to 100 °C
On a D1 they are on (two of them) whenever AC is on. On the D2, as above, controlled by the brain.
#5
Use this link to get the Discovery II electrical manual
http://www.google.com/url?sa=t&rct=j...1bTuJA&cad=rja
Cooling fan relay supply
A feed from fuse 5 in the engine compartment fusebox, is connected to the contacts of the
cooling fan relay.
Cooling fan motor operation
When the main relay is energised, a feed passes from the relay contacts to the coil of the
cooling fan relay. The cooling fan relay coil is earthed on a BP wire (Td5 engines) or a GW
wire (V8 engines) to the ECM.
When conditions are correct, the ECM provides the earth path which energises the cooling
fan relay coil closing the contacts. The feed from fuse 5 in the engine compartment fusebox
passes through the cooling fan relay contacts and from the fusebox to the cooling fan motor
on a BN wire. The feed operates the cooling fan motor which is connected to earth header
C0018 on a B wire.
http://www.google.com/url?sa=t&rct=j...1bTuJA&cad=rja
Cooling fan relay supply
A feed from fuse 5 in the engine compartment fusebox, is connected to the contacts of the
cooling fan relay.
Cooling fan motor operation
When the main relay is energised, a feed passes from the relay contacts to the coil of the
cooling fan relay. The cooling fan relay coil is earthed on a BP wire (Td5 engines) or a GW
wire (V8 engines) to the ECM.
When conditions are correct, the ECM provides the earth path which energises the cooling
fan relay coil closing the contacts. The feed from fuse 5 in the engine compartment fusebox
passes through the cooling fan relay contacts and from the fusebox to the cooling fan motor
on a BN wire. The feed operates the cooling fan motor which is connected to earth header
C0018 on a B wire.
#7
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