A motor-fan shroud is formed at its lower portion with a supporting portion having a hole and at its upper portion with a first and second clip portions arranged apart from each other in a width direction. A reservoir tank is formed at its lower portion with a projection extending downward and insertable into the hole of the supporting portion and at its upper portion with a first and second ear portions insertable from above into the first and second clip portions, respectively. A first clipping surface of the first clip portion has a substantial half-ball shaped projection to be fitted in a hole of the first ear portion, while the second ear portion has a claw to be latched by the second clip portion so that unlatch, in an upward direction, of them can be prevented.