i was tryin to pull codes.when i jumped a and b then turn the ignition to the on position my fans clicked on.i swear i can never get them to come on without my constant on switch.

Had you just finished driving it? The fans will come on at a set temperature.

no they never come on! i could hear them click on and then click off when i pulled the jumper.even tried it twice to confirm it.

The system always commands the fans full on when you pull codes, just to confirm they are working as they should be. The question is, what temp is the Bonne running at? Do they come on when you turn on the A/C?

I just read in another thread that your Bonneville normally runs at 150*. Simply put, that is too low. Stock thermostat should maintain the vehicle at at least 195*. Fans come on around 200* I believe. Biggest cause of that is a faulty thermostat. We may have just added something to your to do list.

yes the fans come on when i turn on the a/c.

my bonnie usually runs around 200/220 degrees.

I believe factory fans are set up as follows:
Fan 1 On at 212* Off at 208*
Fan 2 On at 226* Off at 223*
They also have speed determined settings and always are on when the AC is on.

i swear mine dont come on by themselves.but, what u say is normal,218,i thought was freakin hot,so i wired the fans and havent took that chance since.