Asking help about another car
 

Is it ok if i can ask some advice about my other car a 620ti

Of course. Someone may be able to help.

Thanks. Well its a rover 620ti having problems with coolant fans not kicking in unless the sensor is unplugged ive tried 3 sensors still no luck i asked about the relay but was told if they come in when sensor unplugged the relays are working im out of ideas now

Found this.

https://www.mg-rover.org/threads/199...n-town.428888/

hope it helps

If the ECU starts the fans when the sensor is unplugged the ECU and the fans are ok, and so is the wiring to the sensor so I would change the sensor, about £10 from DMGRS.

This is my third new sensor all genuine ones aswell but someone's told me they had 6 only 2 of them worked

I had this issue on my ZR last month after years of having to run without the sensor plugged in.
Despite fitting a new sensor I had the same issue; had the car in at the garage and they reset the sensor. Good as gold.

I didn't know you could do that.

Didnt no you could reset sensor.

Back again i had my ecu tested at best of british and was told its fine fitted another sensor from a friends car still no joy on the fans coming on

Fans
 

Hi all after having trouble with my fans i brought another new sensor and coolant cap run the car up as the gauge past half way still nothing started creeping towards the red and about to swich off i looked and they was on but slow and it brought the gauge bk down does this seem abit high before they come on no sign of it boiling up or anything

All beyond me I am afraid.

Do the fans run at speed if you wire them straight up to the battery, If you can do that.

Maybe they are knackered, not on the sensor side.

Is the temp sensor the correct one? Could be set to the wrong temperature to ensure they throw the relay to turn the fans on.

The fans come on high speed when sensor unplugged i have got the sensors from rover spares by me correct part numbers it gets to 3/4 just over till the fans come on and they do bring it back down id of thought it would of been half way or just over i can hear the relay click on and off in passenger footwell

Plug in an OBD2 reader and see what temperature the ECU is seeing.