Hello! hope someone can advice on a 6n2 1.4 tdi radiator fan not coming on at all. I have checked all the basics. all fuses are good in the fuse box in the dash, all fuses are good on the fuse box on top of battery including the metal ones (removed and checked). I have also tested the fan directly with the battery and it spins. I have connected the two pins together on the fan switch in the radiator and the fan spins. The fan switch is a triangle shaped with only 2 pins from the factory (red/white & red/black). I have also tested for 12v on the fan switch wire and there is power in (red/black) wire. The fan itself has 2 wires (red/white and brown). There is ground on the brown wire via test light. Is there suppose to be 12V constant power on the (white/red) wire of the fan? Because there is none when ignition is ON. Is there a relay under the dash for the fan that I can replace? Also the horn does not sound but that is not important at the moment. Help Please!

Edited 11 August, 20233 yr by rsaha

What year is the car please?

I guess it doesn't have A/C?

Edited 11 August, 20233 yr by Pete1

1 minute ago, Pete1 said:

What year is the car please?

2001 Y plate

That's odd. In my collection of wiring info, there's no 1.4 TDI mentioned for 1999> ? 

 

Anyway, if the fan thermoswitch connector has just two wires, I don't think there will be a relay anywhere, it will be directly powering the fan if and when it gets hot enough for the thermoswitch to turn on.

Two fault scenarios could mean this isn't working

1. The thing isn't getting hot enough due to water pump and thermostat combination not circulating enough coolant past it.

2. The contacts of the thermowitch have burnt out so that even when it does get hot enough, and make the connection it isn't a good enough connection to pass the necessary current to start the fan spinning up.

 

Is the engine actually getting too hot? What does the gauge read when you've driven for say fifteen minutes?

 

 

yes the engine is getting hot, I have yesterday put new thermostat and cambelt/water pump thinking that might be the issue, also flushed the heater matrix both ways with good flow, i have not driven the car but left to idle for 1 hour and coolant pipes were getting hot, but fan refused to spin even at temp gauge sitting at normal operating temp, eventually water started to boil and come out of coolant bottle but fan did not come on even at that temp.

I suggest changing the radiator thermoswitch then. 

1 minute ago, Pete1 said:

I suggest changing the radiator thermoswitch then. 

yes i am going to change that and update what happens, thanks for the help

When you say you flushed the heater matrix, do you mean the one in the cabin, or the radiator?

 

11 minutes ago, Pete1 said:

When you say you flushed the heater matrix, do you mean the one in the cabin, or the radiator?

 

the cabin one, i flushed it through the two outlets with garden hose and the flow was good both ways  I also flushed the radiator too with good flow.

Edited 11 August, 20233 yr by rsaha

Took the dash out today, found out the heater matrix had a small puncture at the bottom. And someone prior to me fitted the heater matrix pipes the other way round as there is a cowboy repair to one of the matrix pipes.

anyone has a photo or diagram to show which matrix pipe fits which part of the thermostat housing? that is, left matrix pipe to bottom of the thermostat housing and right matrix pipe to the top? or is it other way round? just want to be clear on fitting it in right place.

A photo would probably be far more use, but see if this page helps at all heat exchanger; coolant hoses - Polo/Derby/Vento-IND(PO) [EUROPA 2001 year] (7zap.com)

 

For what it's worth, I doubt it makes any difference which way the coolant flows through the matrix.

thanks for the info, the old matrix has an arrow pointing inwards so that would be the inlet.