Radiator fan only working on low speed.3pin plug

[dazzerT251900td]

Hi There everyone.
I wonder if someone can me work out why my fan only works on low speed when I bridge the wires on the temperature sensor switch which is two speed.No power on high speed at electrical switch 3pin plug.
My van is a diesel and went to MOT last week and after 45 mins still no fan kicking in.
There is power to low speed but not high speed on the 3 pins.
Could it be a relay fault behind the fuse board,if that is where the relay is ,or on the A pillar .
Checked fuses and all looking good and cleaned them up and earth crowns look okay.
Thank you for your help in advance.
Kind regards Darren.

[Aidan]

The 2nd stage is controlled by the relay atop of the 50amp strip fuse, so check the fuse is intact and check the contacts to the relay are clean and check the operation of the relay

if the fan spins on stage 1 then the fan motor is working, stage 1 is supplied via series resistor to limit speed, stage 2 is full power with the relay conrolling power supply

wiring diagram on Syncrosport website

diesels don't always bring on stage 1 fan just sat idling, especially in cold weather facing an easterly breeze, they get sufficient passive cooling especially the TD bodied vans as they have better airflow

[dazzerT251900td]

Hi Aidan.
Thank you for your help.
I’ve ordered some relays from Brickwerks and will let you know what I find.
Cheers

[Oldiebut goodie]

My rad fan never came on with my 1.9 diesel - it never got so hot that it needed to do so. Never gave it a thought as it never overheated. I suppose it all depends upon how hard you push your engine, I never hammered mine.

[dazzerT251900td]

Hi.
Yes my AAZ is the same with the early opening thermostat and oil cooler at the front from Brickwerks but last summer when it was hot outside the temperature gauge went really high when I was stuck in a jam for half hour.
Then last week in the MOT for 45 mins on tick over ,when I returned to the van and reversed out of the garage the temperature gauge was past half way when it usually sits below half way.
I’ve only noticed it on these two occasions because I haven’t used it much in the winter.
I’ll let you know cheers.

[dazzerT251900td]

Hi There.
Just to let everyone know I changed the relay on the A pillar above my bullet fuses(the small one) and now I have both speeds on my radiator fan.It was difficult to get to because of all my old wires which over time have stiffened up plus dash board in the way.But now all good ,thank you for your help.Cheers.