Repairing or replacing an air cooler water pump can be done by following these steps:

1. Unplug the air cooler from the power source.
2. Locate the water pump in the air cooler. It is usually located near the water tank.
3. Check the water pump for any visible signs of damage, such as cracks or wear.
4. If the water pump is damaged, it will need to be replaced. You can purchase a replacement water pump from a hardware store or contact the manufacturer for a replacement part.
5. Remove the old water pump by disconnecting the power cable and unscrewing any screws that are holding it in place.
6. Place the new water pump in the same position where the old pump was located.
7. Connect the power cable to the new water pump and screw it into place.
8. Fill the water tank with clean water.
9. Plug in the air cooler and turn it on to check that the new water pump is working correctly.

If the water pump is not damaged, you may need to check the wiring connections to ensure they are secure and connected correctly. You can also clean the water pump and remove any debris that may be clogging it. If the problem persists, it may require professional repairs or replacement.

It's important to note that repairing electrical appliances can be dangerous and may pose risks of electric shock.it may be best to hire a professional from Locals4u for assistance or contact the manufacturer for guidance on repairing or replacing the air cooler water pump.