Tirthankar wrote:
> The Fan in front of passengers seat is giving issues. It turns on even
> when the engine is cold on a morning before started. Recently I had
> changed Thermo switch at the upper hose and temp sensor at the
> thermostat housing lower hose. No helped at all.
> Only mystery is when I go for long drives the fan doesn't turn on. But
> on cold it does. However on turning on the AC swtich both the condesor
> fan as well as radiator fan come on. What could be the problem.
> Now a days I keep the battery terminal disconnected -ve to save the
> battery. Earlier also the fan used to run till it sucked the battery.
> Could it be a wiring problem.
> What is the difference between fan timer unit and fan relay.

It should have two relays (one for AC, one for condensor) and they are
both the same type of relay.
The easy thing to try is to pull both relays out (mark them first, so
you know which goes where in case you do find that the condensor relay
is bad).
Then put the AC relay in the condensor slot and see if it now works
correctly.
If it does, replace the condensor relay (obviously the other one you
pulled out - now you see why you'll want to mark them).

A relay is an electric switch. It activates a contact when current is
sensed on its input (coil).

The timer unit takes care of keeping the relay turned on when the car
is hot and you turn the car off. It could be that the connection from
the sensor to the timer is bad so follow the wire from the sensor back
and make sure it makes good contact.

Remco