Mechanics

ELECTRIC COOLING FANS WILL NOT TURN ON

1998 Buick Century

Engine Cooling problem
1998 Buick Century 6 cyl Two Wheel Drive Automatic

Electric cooling fans will not turn on when engine gets too hot. I checked the fuses and relays. They are good. I replaced the CTS and it did not fix the problem. I did discover that if I disconnect the electrical connector to the CTS, the electric fans will turn on and stay on. I have left the connectors disconnected temporarily so that the engine does not over heat. In doing this, I've noticed a drop in gas mileage. Please help. Oh, the radiator fluid level is good.
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Deanlandis
October 3, 2010.



The reason your gas mileage dropped is you disconnect the cts and it doesn't control the fans. plug it back in. There are 3 relays not 2 and 2 large fuses. they all must be checked. I'm including a diagram. If it's not a relay, then you'll have to have a pro check it for a bad connection or shorted wire coming from or to the pcm....


http://www.2carpros.com/forum/automotive_pictures/406719_relay_diag_1.jpg


Hmac300
Oct 3, 2010.
How do you test the relays for the coolant fans

Tiny
Douglaseboggs
Sep 17, 2012.