Rad Fans

Longtime Buick owner, New 95' Buick Regal Owner. Just wondered if anybody can tell me what brings the other fan on. Is it normal for just the Driver's Side Fan to work when A/C is on and under normal Operation? Just wondering what conditions bring the Passenger side one on? Thanks guys....

On the 3.1 liter engine the two fans work independently from each other. They are one speed fans and the primary fan comes on when coolant reaches a certain temperature while the second fan comes on only when coolant reaches a higher temperature. They don't automatically come on with the A/C so you could have the A/C on and both fans off.

On the 3.8 liter engine the the fans only work together. When the coolant reaches a certain temperature a relay runs the fans in series so they both run at low speed. When the coolant reaches a higher temperature the fans are run in parallel so they both run at high speed. On the 3.8 the fans also always run when the A/C is on.

So if you have a 3.1 and only one fan is on, there is no problem. If you have a 3.8 and only one fan is on there is a problem with a fan or a relay.

This is how the older regals work. Somewhere around 94? the 3.1 became the 3100 (heads, sfi, etc..) but the fans probably operate in the same way.

Phew, ok thanks for the reply it really hasn't got hot enough around here yet to bring the other fan on so that's good to know. It has the 3.1 liter engine in it so all is well.

Thanks again, aren't these forums great? :D