[ES4]

Hi, just fitted a new AC cooling fan to td5, I would like to fit an override switch so the fan runs full time when towing (Horse Trailer)
Looking at the circuits relay 5 (R117) is energised when its coil is grounded via pin C0573-11 fed from ECU C0658-4. Black/Purple wire.
Its quite easy to reach this wire to splice in a switch which would ground the relay coil and energise the fan.
This grounding of pin 4 on the ECU wouldn't cause any problems ??
Thought I better check first.
Thanks.

 

[Stanleysteamer]

Question 1, does your Td5 already have AC?
Question 2 what makes you think you need extra cooling?

I have a TD5 and use it to do heavy towing including up the Massif Central, and it is totally standard, never a whisper of an overheaing problem. And although I have AC fitted I don't use it when driving that route (500 miles).

 

[ES4]

Yes we have AC but it wasn't switched on, but the fan pulled in when towing up hill, the Temp went up above normal but it didn't overheat and quickly went down again. the viscous fan tests ok. Just thought having the fan running would pre-empt any chance of overheating.

 

[sierrafery]

This grounding of pin 4 on the ECU wouldn't cause any problems ??

No probs at all, others did it as well

 

[sierrafery]

but the fan pulled in when towing up hill, the Temp went up above normal but it didn't overheat

If the gauge went above normal means it was too hot already cos it leaves the middle at 120*C and the electric fan kicks in at 110 by default, so if it ran full time means there was more than 110*C and that will kill the engine on a long run... IMO you have a cooling issue cos it's not supposed to get hotter than 105*C no matter what you tow unless you have much bigger tyres than the std dimension. Try to stop the viscous fan with a rolled up newspaper when the engine is hot and if you can replace it cos it doesnt do it's job

 

[ES4]

Thanks, didn't test the viscous fan while it was running, tomorrows job