Cabin blower fan not working at all

Hi,

I saw you answers on a post here regarding 1998 Isuzu Trooper that is a Holden Jackaroo in Australia. I have 2003 3.5L V6 petrol version of it.

The A/C blower fan in the cabin is not working and from the circuit diagrams in the workshop manual I figured out the culprit was starter relay.

25 amp fuse was not blown but have no voltage in it. Nor was the "heater and A/C" found faulty. However, the base of the relay did not have power at point 1 i.E. Coil of relay. However, it has twelve volt supply at two switch of the relay.

In the diagrams its given that the heater relay coil takes its twelve volt from starter relay, I replaced the starter relay and found that fan started blowing. But when I drove the car and other switches became operational the blower fan stopped again.

Now it did not work no mater I start the car or simply turn the switch to "on".

What could be possibilities causing damage/cutting twelve volt off from the points 1 and 2 of the starter Relay. Please see images.

Need your guidance please. Thanks