my mehran's fan is acting up. first of it turns on when needle in almost 3/4 of the total gauge. secondly, when i turn on ac the fan is direct and works fine and needle remains in middle of the gauge but as soon as ac trips temperature starts to rise and needle goes to the right a bit and when compressor kicks in again it goes to normal. it kept on for the whole summer with no major problem but now two days back when i turn on the ac the fan was running but when ac trips the fan is not running even on temp it should and needle is touching red mark on the gauge. same is the case when ac is not running. the fan just wont start but it will when ac compressor is engaged. whats the problem?
what could cause this problem and what parts should i change?