planning to add an aux electric fan for an old car. first time i'll be doing this.

gusto ko sana malaman kung may switch na mag control sa aux fan na ito, yung parang sa mga bagong kotse ngayon na nag aactivate lang yung fan every 30 seconds or so (hindi parating naka-on) para hindi naman masunog yung fan motor prematurely.

gusto ko sana may controllable switch mounted sa dash, tapos selectable: low (1 cycle per minute), medium (1 cycle per 30 seconds), and high (on all the time). hindi naman kasi maganda yung sobra sobrang cooling... pag maulan or malamig set ko lang sa less cycles...

what do you call this type of switch (if any exist)? cost? alam ko kasi sa aux fans pag on mo ng switch nun derecho on na yun eh.

thanks for any help.