Hi guys

 

Puzzled

just wanted to ask a question

 

I have two wires from the fan relay switch that i am trying to find out where they go

 

 

 

a brown/ blue and brown /green goiing into the my passenger side of the car 

 

 

I have found the same size and colour wires coming out of the a/c and heater compartment

are they the same, because i dont get continunity

 

I tested the black and purple wire from a/c/ fan heater switches and get continunity to the fan relay switch

 

Look forward to some help

 

 

 

 

 

 

 

 

 

 

Yes. The fan controller also controls the a/c clutch. For the a/c to run, the fans must be running so the a/c has to be routed via the fan controller.

What problem to you have?

rad fan wont work

 

 only works when i turn on a/c only works intermittently

 

bridged the sensor on engine block but the fan doesnt work

 

changed fan relay switch, sensor on rad, sensor on engine block and water temp sensor stil no joy

 

checked wiring with power probe from engine block temp sensor only get neg light but  no positive light 

so assuming a electical fault started to test wires from rad fan relay switch hence the posting above

 

checked temp sensor from engine block wiring back to ECU i get continunity

went through ecu unit testing found five possible wires to check(three go back to sensors for engine block )- down to the last two a blue/white and i think a red/brown going into the passenger side compartment

 

hope this is as clear as mud--

cheers

The thermo switch is on the radiator - not the block. Also check the two fuses that feed the fan controller.

checked fuses ok

 bridged thermo switch fan worked on slow and fast speed but now only works on slow speed 

 

new fan in situ

the a/c works but fan not working when a/c on

sometimes during unplugging and testing i managed to get a/c fan working  but not always

 

thats why i have gone down a possible route of a  problem with the wiring/ continunity

What is the engine code (on the options label under boot carpet) and year.

BMD  1.2

55'

Actually, there are three fuses...

F3 (40A) High Speed

F8 (30A) Low Speed

F11 (5A) Controller supply

Short brown/blue to brown at thermo-switch to test low speed

Short brown/green AND brown/blue to brown at thermo-switch to test high speed

i have tested all the fuses in both battery area and fuse box

i have tried the last suggestion using all three connections

 

 will try asap

 

 

if they do set the fan working

do you know why the engine block sensor when bridged does not set the fan to work?

 

thanks

I meant to say i have not tried the bridge the three together

 

but will try

 

Thanks

do you know why the engine block sensor when bridged does not set the fan to work?

 

 

 

Because the fan sensor is on the radiator.  The one on the block doesn't control the fan.

 

Think the part number for the sensor is 1J0959481A

 

Edited 10 April, 201412 yr by TMB

~Hi  there

 

i have changed and tested the fan sensor bridging worked on slow speed only but still no joy with the fan working when i switch on a/c

 

i also tried bridging the coolant temp sensor  as i saw on utube  that if you bridge the wires then the fan should workbut mine doesnt?

 

as i said earlier i have a new fan but still no joy...

 

My car was overheating and stalling- the fan was not working this caused my ehaust valves to be damaged and causing bubbles in coolant,  which i have now changed exhaust valves but dont want to start driving until i get fan sorted as you can understand..

 

so any help with the wiring suggested earlier would be really helpful-- i am planning to follow the wires into the car and hope they end up at the a/c and fan blower controls, however checked coloured wires at the back of a/c switches and the only two that match are the brown.blue andbrown/green but as i said no continuity?

 

any suggestions would be appreciated big time

If the fuses are indeed intact (checked by meter - not visually), it sounds like you have a faulty fan controller. Bridging the coolant temp sensor will not bring on the fan. The fan cools the radiator not the engine. There's no point switching on the fans unless the radiator is hot and they would be on anyway as the thermo-switch would have switched them on.

Unless you are stuck in traffic at 30°C or have the a/c on, you don't need the fans.

Have you checked the thermostat and water pump?

Have you had the cooling system pressure tested?

Are you loosing coolant?

fuses checked by meter

changed thermostat

 checked water pump no lost of coolant visble

 

changed fan relay switch twice as i bought the first one second hand just bought a brand new one still no joy with a/c  fan working as i said earlier intermittently.

not tested cooling system pressure

 

Just interested how does the cooling system pressure effect the a/c fan working?

I doubt that your overheating problems were caused by a faulty fan.

What is the fan controller part number you have fitted? IIRC, it should be 1J0919506M (the trailing letter is important)

rechecked the fan relay part number and it is exactly the same as the orignal one taken off

 

same as the number you quoted