Injection relay heats 98?

I have a problem the injection relay is heating me is a goal year 98? I really don't understand why he warms up? Perhaps it is normal .. if anyone knows how to explain the reason for heating. I also have a doubt when the electro -ventilator goes up the temperature needle will be normal. and when the low electrventilator is turned off. Also when I give all the volume to the player or radio, also raise the temperature needle. I thank you who can help me. My cooreo is