Electric fans
Acct Suspended APR 2026 by request
Joined: Dec 2010
Posts: 10,367
Likes: 1,272
2020 Corvette of the Year Finalist (performance mods)
C5 of Year Winner (performance mods) 2019
depends on what's in your tune, they can be commanded to turn on and off at any temperature... if you have hptuners you can check
Thread Starter
Pro
Joined: Jan 2003
Posts: 577
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From: West Plano TX
Factory set turn on temp for fans at low speed is 226. BOTH fans run in either low speed mode or high speed mode which starts if the coolant temp reaches 235 degrees. If you are running the AC then the fans come on in low speed mode at 185 degrees. High speed mode with AC running is still 235. Be aware that the PCM commands fans off when the vehicle speed exceeds 35MPH. Apparently GM felt that air flow through the radiator was better at 35 and faster than running the fans.
If you had only one fan running then there is a problem.
As mentioned by neutron82 the turn on temp for both low and high speed operation can be programmed to values different than factory settings.
If you had only one fan running then there is a problem.
As mentioned by neutron82 the turn on temp for both low and high speed operation can be programmed to values different than factory settings.
Team Owner
Joined: Mar 2001
Posts: 21,325
Likes: 3,841
From: small town in S.E Pa. PA
St. Jude Donor '03-'04
8VETTE7 has this issue cover with good clear input...
One other thing I will add is a C5 is a bottom feeder. Its like a vacuum cleaner sucking in air and also debris . How you keep your engine cool is by allowing both the radiator and the AC condenser, which sits in front of the radiator to be a clean as possible. Heat transfer is a product of air flow through both of these components. AS small as the radiator is, and its design restraints, it should be cleaned once a year.
Having a free flowing condenser and radiator will go a long way in keeping your engine in the " sweet spot " for coolant and oil temperature.
Bill aka ET
One other thing I will add is a C5 is a bottom feeder. Its like a vacuum cleaner sucking in air and also debris . How you keep your engine cool is by allowing both the radiator and the AC condenser, which sits in front of the radiator to be a clean as possible. Heat transfer is a product of air flow through both of these components. AS small as the radiator is, and its design restraints, it should be cleaned once a year.
Having a free flowing condenser and radiator will go a long way in keeping your engine in the " sweet spot " for coolant and oil temperature.
Bill aka ET
