Hot car
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Heel & Toe
Joined: May 2018
Posts: 17
Likes: 2
Hot car
car always ran 220 to 225. After a/c check brought it home a/c will not kick fans on. Let car idle to 235 before shutting off So apperently the ecm wouldn’t kick them on either. Checked fuses everything ok. Nothing blown.
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
welcome to the c5 cooling fan world
... the first thing I would do is disconnect the fan plugs and put 12v to each one just to make sure the motors are good... there are 3 relays that control the low and high speed fans... if the motors are good then take out the cooling fan 1 relay and jump pins 30 and 87 in the fuse box, this should turn the fans on low speed... verify that both fans are on and let us know if they work or if one shuts off or if neither work... if neither are working then check for voltage at the relay pins of the cooling fan 1 relay in the fuse box, one of them should have 12v at all times even with the key off... if you have voltage then most likely the culprit is a bad ground which is located at the ground junction on the passenger side frame rail near the coolant tank... but just let us know what you find and we can go from there
... the first thing I would do is disconnect the fan plugs and put 12v to each one just to make sure the motors are good... there are 3 relays that control the low and high speed fans... if the motors are good then take out the cooling fan 1 relay and jump pins 30 and 87 in the fuse box, this should turn the fans on low speed... verify that both fans are on and let us know if they work or if one shuts off or if neither work... if neither are working then check for voltage at the relay pins of the cooling fan 1 relay in the fuse box, one of them should have 12v at all times even with the key off... if you have voltage then most likely the culprit is a bad ground which is located at the ground junction on the passenger side frame rail near the coolant tank... but just let us know what you find and we can go from there
