Fan running on a cold morning?

[Y-Ellow]

Is it normal for a fan running right with a start of the engine on a cold (20F, -5C) winter morning?
1991, 4WD, 5.7L Suburban, VIN - K.
Thank you.

[GNW]

If we are talking about the radiator fan, yes it is. Here is how you can tell if it is working okay. Start up the vehicle and high idle it for about 45 seconds. At about 30 seconds into running, the cooling fan should start to make less noise. This is caused by the fluid in the fan clutch warming up allowing the two fan clutch parts to move seperately. If the fluid were to get too warm it would cause the fan to kick in until the temp comes down again.

[Y-Ellow]

Thanks GNW,
that's a relief, becouse I thought there is something wrong with the thermostat.
Thank you.