Volvo RWD 900 Forum

Hi,

Still trying to diagnose my ECC that isn't performing to its best.
Reading in my workshop manual for the LH2.4 fuel injection system and EZ116K ignition system, it describes the electric cooling fan. It says;
Fan is running with reduced speed if
-Temperature of cooling system is above 102C or
-Pressure in A/C-system is above 17 bar on high pressure side and vehicle velocity is below 100km/h.
Fan is running with high speed if
-Temperature of cooling system is above 115C or
-Pressure in A/C-system is above 22 bar on high pressure side.

So out I went to test fan for high and low speed operation and see if I could get the pressure sensors on the condenser to react.
Shortcutting the two leftmost (travelling direction) connectors indeed started the fan in high and reduced speed.
Next test was to start engine with A/C engaged and see if the pressure sensors were alive. The thing that puzzled me now was that the fan started even though the two pressure sensors were disconnected. The engine was cool when I started it so it wasn't due to that.
The pressure sensors never activated, but I didn't run it for long and it was on a cool evening. I'll do that again in the hot sun one day to see if they come on.

The Volvo manual I have is for up to 1992 years model, and I don't have the ECC manual. Anybody knows if something changed for 1993?
Obviously there are more factors that start the fan than those above.


Thankful for any thoughts,
mila