Technical Mk2b radiator on fulll time

[hkofoed]

Hi guys - i have a mk2b racing car in the antipodes, that i run in the local Trofeo series. I recently replaced the engine with a Stilo 188 equivalent (3 extra hp haha).

Prior to the engine swap i had the air con unit removed and the radiator worked normally.

After the engine swap the radiator fan is now on permanently. Bit of a mystery.

Just wondering if anyone else has had their air con removed and may have had the same issue. Im hoping i might be able to remove a fuse or something simple to de-link the air con electrical operation from the fan. Thanks in advance !

 

[RalphM]

Have you used the temp sender from the org engine? if not it could be the sender on the new one.
or even not plugged in properly.

 

[hkofoed]

Have you used the temp sender from the org engine? if not it could be the sender on the new one.
or even not plugged in properly.

Good call will give it a go in the morning, cheers !!

 

[AndyRKett]

Where aircon is fitted the cooling fan is a twin speed model, so if you're sat in traffic with the aircon running it will cut in a high speed can to keep air flowing over the condenser and keep the aircon cold, otherwise the pressure in the condenser would go up and the temperature of the cabin would.

The normal engine fan is run at a lower speed if the engine heat creeps up.

I would bet my life savings on it, that removal of the aircon set up (and all its sensors) has left the ECU blind to what is going on inside the aircon system. As far as the ECU is concerns it is still there.

So as a fail safe its running the radiator fan constantly to protect the aircon system and engine as it doesn't actually know what's going on.

If I remember correctly these cars use a single pressure sensor to monitor both high and low pressure states. So plugging the aircon pressure sensors back in might clear the problem.
The other option is to have the aircon coded out of the ECU.

 

[hkofoed]

Where aircon is fitted the cooling fan is a twin speed model, so if you're sat in traffic with the aircon running it will cut in a high speed can to keep air flowing over the condenser and keep the aircon cold, otherwise the pressure in the condenser would go up and the temperature of the cabin would.

The normal engine fan is run at a lower speed if the engine heat creeps up.

I would bet my life savings on it, that removal of the aircon set up (and all its sensors) has left the ECU blind to what is going on inside the aircon system. As far as the ECU is concerns it is still there.

So as a fail safe its running the radiator fan constantly to protect the aircon system and engine as it doesn't actually know what's going on.

If I remember correctly these cars use a single pressure sensor to monitor both high and low pressure states. So plugging the aircon pressure sensors back in might clear the problem.
The other option is to have the aircon coded out of the ECU.

Brilliant - thanks, coding may work