Cooling fan

BRMFUN · 26-04-15, 10:48 AM

I have had a quick search but could not find what I needed so apologies if I missed something.....

My 120 MK1 cooling fan is not working, I have checked the relay and fuse under the bonnet all appear ok!

How about the Brown sensor?? If I take the connector off should the fan come on? And if it does what does that mean, new sensor?

talkingcars · 26-04-15, 01:19 PM

Yes, if you disconnect the coolant temp sensor (CTS) that feeds the ECU then the ECU should command the cooling fan to come on, if the fan doesn't come on then the fan or it's power supply is goosed.

How do you know the fan isn't working?
You need the ECU to be seeing 96' for the fan to come on.

Have you got an OBD2 reader?
The coolant temp you see on this would be the same as the ECU.

SARENG · 26-04-15, 11:45 PM

The fan doesn't come on, on my 120 until over 100degrees according to my OBD2 reader?

talkingcars · 27-04-15, 04:27 AM

You don't hear the lower speed fan from inside the car, the higher speed comes on at 102'.

BRMFUN · 27-04-15, 08:28 AM

I have a OBD2 reader so will check it out one night this week!

BRMFUN · 05-06-15, 04:21 AM

Ok finally got round to checking this! Obd says 100 ' but nothing, I have disconnected the sensor and still no fan, I have swooped the relay in the engine bay for a known good one and still no joy!?

BRMFUN · 05-06-15, 04:22 AM

Ok finally got round to checking this! Obd says 100 ' but nothing, I have disconnected the sensor and still no fan, I have checked the relay, which is good, and still no joy!?

MG ZS STE · 05-06-15, 06:25 AM

can you turn the fan?

BRMFUN · 05-06-15, 07:53 AM

Yeah all turns ok, air on fan/s don't work either, just spotted that!

petet16 · 05-06-15, 10:24 AM

The fans should run when the cts is disconnected, mems is programmed that way, so if they don't run, it's either the fan failed, or a power supply issue, a quick prod round with a multimeter will show if power is reaching the fan, or not.