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Radiator fans only come on with A/C
Posted: Wed Oct 03, 2018 3:04 pm
by Kevdadi
Hello-
I have a 2003 3.8l Bonneville that stays cool because I kive in 90+ degree Florida! If I turn off the air conditioning the fans do not run... no overheating, but temp goes a tick over 200 and holds steady.
I looked around a little bit for some ideas, but do not know how to diagnose.
No overheat condition, but rad fans wont come on without the air conditioning...
Thanks!
Re: Radiator fans only come on with A/C
Posted: Wed Oct 03, 2018 9:12 pm
by AJT2004
From what you describe there is no problem and the cooling system is functioning normally.
Re: Radiator fans only come on with A/C
Posted: Thu Oct 04, 2018 7:18 pm
by luke_dubs
Sounds normal to me as well. I thought I had an issue as well (same diagnosis as you) but nope. Everything is okay.
Re: Radiator fans only come on with A/C
Posted: Mon Oct 08, 2018 1:35 pm
by rustyroger
Let the car idle in still air and see if the fans come on. They shouldn't until the coolant temperature reaches around 220 degrees, and should shut off when it gets below maybe 180.
If you keep moving the fan will almost never come on, the flow of air through the radiator is enough to keep things cool.
Roger.
Re: Radiator fans only come on with A/C
Posted: Tue Oct 09, 2018 12:29 am
by RJolly87
If the gauge holds steady a tick above 200 while just sitting there idling, either the fans are coming on, or there is enough air moving through the radiator (a breeze) to keep temps in check.
As mentioned, fans don't come on low until 215 (approx) and hit high if it pushes beyond 225, or if they are required for air conditioning. It's very rare that the fans will ever run at high speed under normal conditions, aside from A/C.
If the fans are on low, it's possible they are running but you simply can't hear them. They should shut off once it cools down around 210 or so.