7 replies to this topic

[T1m]

Hi guys

 

im wondering if anyone can advise me. I’ve stripped my MPI and a previous owner has spliced in a override switch to turn the radiator fan on and off manually. My question is do you think this was done because of an overheating issue and should I put the wiring back to factory?

 

tia, Tim

[stuart bowes]

when I did it once it was on an old volvo, because I converted from a fan on the pulley to an electric fan, where there was no place in the radiator for a thermostat switch thingy (I knew you could get aftermarket temperature switches, I just never got around to buying one)

 

whenever it was on the switch got red hot and I quickly learnt that it should be through a relay (which yours probably is as well at a guess)

 

you say it's an 'override' but does the fan still come on by itself if you leave the switch off and get the engine hot

 

(i.e. is there something wrong with the original switching mechanism / sensor / wiring, however it works in the MPI)

Edited by stuart bowes, 23 October 2022 - 02:37 PM.

[roblightbody]

Because the mpi doesn't have a mechanical fan, like every previous model of mini, the electric fan is absolutely critical and will be required far more often... It should be controlled automatically by the original wiring... And if that doesn't work you'll need to get the underlying fault fixed.

The mpi had the same setup as any modern car... Unlike every previous mini.

[T1m]

Much appreciated folks. I will put the wiring back to standard. It was run though the relay and looked competently done but I do not know if it was also controlled by the ECU.

[stuart bowes]

my question though is why make it manual, unless there's some issue with the thermostat switch or other related issue

 

so just putting it back to standard may not be the end of the issue that's all

[T1m]

I agree, rather hoping the resto will resolve what ever the issue was! Just peeled off the classic outer sill glued over the original one today so fun times ahead.

[Aria Aradhea]

The MPI, IIRC, has a known wiring fault to the aux fan where the cable is too short, causing it to fray and not engaging the aux fan when needed. It should be corrected under warranty, but many didn't. Perhaps it is just as simple as that? However, it is always a good idea to check whether the car has issues or not.

[Quinlan minor]

The problem was the wire to the coolant temp sensor was too short to cope with engine movement.

When contact was broken, the ECU assumed overheat and powered up the fan.

A DPO may have inserted the switch to stop the fan running constantly, not a good idea!

Simply extending the wire, to the sensor, will fix the problem and restore normal service.