coolant level sensor

[Yoni_d]

Hi All

When my radiator water completely leaked during driving a few days ago - the coolant level indicator lamp didnt go on
Today I started to see where might be the problem. here is what I have done till now:

1) Lamp in the instrument cluster is good (it is on when I start the car and then turns off)

2) I pulled off and bridged the plugs on float switch. started the car and waited for 20 sec as it was said in the manual. result: no warning light.

3) pulled the central warning unit and checked the wires. Result: looks good but still no warning light.

When I was looking at the electrical schema (attached) I have noticed that the wiring of the coolant level sensor goes into a Time Relay...
Here I am a bit lost...Where is the Time Relay location and is it exists in the 1980 model?
I assume that the Time Relay might the problem since this is the only part that I havent checked and everything else looks ok.

Any ideas?

Thanks!