Technical Overheating in traffic

[branton rhino]

Hi,

My daughters Sei (1108 MPI 2003) overhaets when she is in a traffic jam. It is fine otherwise. I assume that the thermostat is working otherwise it would boil on a decent journey and this does not happen. (I am 200miles away so I am making a few guesses here!)

Is there a temp sensing radiator fan switch that controls operation of the electic fan? If not how is the fan operation controlled?

Any help much appreciated

Thanks

 

[bean]

Normally one of two things:

1. Temp switch in rad.

2. Motor has broken in fan so fan doesn't come on- check fuse for fan under dash to see if it has blown. You will nee to buy a whole new assembly for this.

Mine has broke at the mo and i am just managing by having the car vents blowing hot air at max!

Hope this helps.

Nath

 

[arc]

on the MPI there is no fan switch in the rad, it is controlled by the ECU via a relay.

 

[rallycinq]

and the fuse is a maxi fuse behind the battery.

There are two green 30 amp fuses in the holder. If the lid has been replaced upside down you can check the wrong fuse by accident, so check both 30 amp fuses.

Cheers

D

 

[branton rhino]

Hi,

Thanks for the help. I understand:
1. The fuse is a 30A maxi behind the battery
2. There is no radiator switch, just a relay controlled by the ecu
3. If I need a new fan motor I have to buy the complete fan/ motor and supporting framework.

If there is no rad switch how does the ecu get a signal to turn on the fan?
Where is the relay between the ecu and fan motor?
How can I check the ecu is sending out a start signal?

Maybe I am being a bit thick here but any help much appreciated.

Regards

Bill

 

[fingers99]

Check that the fan motorworks by jumping it (+ and -) directly.

If the fan doesn't work, you'll probably find it cheaper to fit an aftermarket fan. (As in much cheaper if you can't find one at a scrappy).

Most fan issues are down to faults on the earth side. Temperature signal is from the green temp sensor on the right hand side of the inlet manifold.

 

[The Professor]

Another favourite fault mode with the MPI fan is that it comes on initially but slows down then eventually stops. I've had two Schumis do this and on the first one the garage swore blind there was nothing wrong with the fan... eventually it didn't even come on at full blast and then slow down, it just started and ran slowly, almost slow enough to see the blades rotating.
My current Schumi is displaying the initial symptoms and I've got a new fan ready to fit.
In both cases the deterioration has been gradual over a period of weeks, verging on months. Nothing wrong with the fuses or wiring, it's the motor.

 

[bsafirebird]

My daughters 2002 MPI sporting is also having a similar problem. I've checked the fan and it's OK but can anyone tell me which is the relay that supplies the power to the fan?
Regards
Neil

 

[rallycinq]

My daughters 2002 MPI sporting is also having a similar problem. I've checked the fan and it's OK but can anyone tell me which is the relay that supplies the power to the fan?
Regards
Neil

I think its also behind the battery. Have you checked the fuses there and also the fan operation?

Cheers

D