Hi all,

i have a problem with my 1.2 8v 2005 mk2b with air-con

the radiator fan works perfectly with the temp sensor but it doesn't work with the AC "on my seat ibiza the fan always works with the AC"

can anyone where is the problem and how to troubleshoot ?

Thanks

hi, sorry not had a punto with AC , des it have 1 fan or 2..??,
if the fan works for std engine cooling, then it cannot be a faulty fan,

problem is either wiring or sensors = IF it SHOULD run on AC !! ??,
Charlie

pretty sure there is only 1 fan even on the A/c versions

It runs are 2 different speeds - which is testable with MES

Slow and fast

Does the AC blow cold?

ziggy

Ziggy122 said:

pretty sure there is only 1 fan even on the A/c versions

It runs are 2 different speeds - which is testable with MES

Slow and fast

Does the AC blow cold?

ziggy

Click to expand...

Engine with AC has two speed radiator cooling fan. This is implemented with two relays and a resistor.

Speed 1 (low speed): ECU puts earth on coil of relay R6. Contact of R6 goes to fan motor via the resistor. The resistor limits the current hence speed is reduced.

Speed 2 (high speed): ECU puts earth on coil of relay R7. Contact of R7 goes straight to fan motor.

Other side of motor is earthed.

12V supply for both relay coils is via fuse F3 (30A) and ignition switch.
12V supply for contact of relay R6 is via fuse F6 (30A).
12V supply for contact of relay R7 is via fuse F7 (30A).


Car without AC only has relay R6 and fuse F6 (30A) supplying both coil and contact. No resistor. ECU puts earth on coil of relay R6, contact supplies fan motor.


I guess that the low speed is to run with the AC

the problem is i can't locate the R6 and R7 relays to see if the problem with the R7

I already found the resistance and will test it as well,

If anyone can tell me which relay is the R7 to see if it's working or not

Thanks

Hi, have a punto mk2 1.2 16v elx speedgear cvt automatic car with AC, when I start the car with blower motor switch at position zero or at the max, the rad fan not comes on, but when I push the same knob to switch on the AC, the rad fan start to operate at slow speed for few seconds and continuously runs high speed all the time until i switch off the AC. After switching off the AC, the rad fan also stops and rad fan normally working with temp sensor changes and everything tested with MES no overheating indication on dash too.Please help me on this.

sandaru said:

Hi, have a punto mk2 1.2 16v elx speedgear cvt automatic car with AC, when I start the car with blower motor switch at position zero or at the max, the rad fan not comes on, but when I push the same knob to switch on the AC, the rad fan start to operate at slow speed for few seconds and continuously runs high speed all the time until i switch off the AC. After switching off the AC, the rad fan also stops and rad fan normally working with temp sensor changes and everything tested with MES no overheating indication on dash too.Please help me on this.

Click to expand...

The ac fan wont always come on straight away
Only when the pressure/temperature conditons are met and then the fan will kick in

If the engine temp did go to high when fan ac was on the fan would simply speed up

Ziggy

Ziggy, the problem is radiator fan operates high speed always when AC on. Observed car parked at idle. What is the operating mode for radiator fan when AC on? is it low speed or high speed?. Just after starting up the car with AC I observed above.

The aircon produces heat in the condenser which sits in front of the normal radiator/fan.
When the air con is in operation and the car is stationary the engine ecu will switch the fan on and off to keep air flowing through the condenser and remove heat from the air con system, regardless of what the engine temp is doing.

What you describe is perfectly normal and in hot weather it's more likely to operate more continuously. In the winter the fan may not come on at all.