Help!
Thread Starter
2nd Gear
Joined: Jun 2012
Posts: 2
Likes: 0
Help!
I have a 1996 vette, cooling fans won't come on, replaced the relays per the dealers diagnosis, still don't come on, when I ground the relay the right fan comes on, left fan doesn't. When it gets hot it seems both fans run at a very low rpm. Could it be the coolant temp sensor? Tracing the wires is challenging. Any suggestions?
Le Mans Master
Joined: Jan 2006
Posts: 5,620
Likes: 206
From: Orlando FL
Lennny Lennny Lennny,
The first thing you have to understand is how is should work normally.
The fans always run together either on low or high speed.
The fans come on in low speed when you turn on the A/C, or when the temperature gets up to 228*.
The fans come on in high speed when the temperature gets up to 239*.
The 3 relays for it are controlled be the PCM and closes the appropriate relays for the correct voltage configuration and speed.
If you digital temperature indication on the speedo looks normal for the expected engine temperature, then the sensor is probably OK.
Relays actually go bad very seldom. How did the dealer determine they were bad?
Now you have to tell us under what conditions the fans don’t work?
The first thing you have to understand is how is should work normally.
The fans always run together either on low or high speed.
The fans come on in low speed when you turn on the A/C, or when the temperature gets up to 228*.
The fans come on in high speed when the temperature gets up to 239*.
The 3 relays for it are controlled be the PCM and closes the appropriate relays for the correct voltage configuration and speed.
If you digital temperature indication on the speedo looks normal for the expected engine temperature, then the sensor is probably OK.
Relays actually go bad very seldom. How did the dealer determine they were bad?
Now you have to tell us under what conditions the fans don’t work?
Last edited by pcolt94; Jun 9, 2012 at 05:28 PM.
Thread Starter
2nd Gear
Joined: Jun 2012
Posts: 2
Likes: 0
Thanks for the reply. The fans do come on at low speed when hot, but do not kick into high speed even when the gauge is showing 250. I can get the passenger side fan to kick into high speed by jumping the relay switch manually. I have checked the grounds and the fuses and are OK. I am going to change the coolant temp sensor as a last effort as I have changed the relays already. Not sure how the dealer came up with the relays as the reason, I just took it there for a diagnosis and thats what they said for $85.00. The fans are not coming on when the A/C is turned on as well.
