LT1 Based Engine Tech 1993-1997 LT1/LT4 Engine Related

Fans Wont Kick In need help fast

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Old Jul 24, 2008 | 09:39 PM
  #1  
darlandz's Avatar
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Fans Wont Kick In need help fast

i have a 95 z28 auto heres the issue relays inside the fuse and relay cover are fine underhood tested them all with running the a/c and they all had the a/c working fine and so i changed the coolant temp sensor in the water pump and still got no fans going.... now im running out of ideas im guessing the coolant sensor in the head is fine since its giving me the right temp reading in the dash so all the help possible would be appreciated.
Old Jul 24, 2008 | 09:44 PM
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What coolant temps are you seeing? Who tuned it? What did they set the fan on/off temps at?
Old Jul 24, 2008 | 09:55 PM
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im seeing what ever temps i stop the car from going to witch is why its sitting in the garage and as far as tunning goes it is not tuned but it dose have a 160 stat you think i should but the stock one back and it might fix that problem?
Old Jul 24, 2008 | 09:55 PM
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the o2 are on the same relay as the fans it could be that. i know the 95s are that way just a thought
steven
Old Jul 24, 2008 | 10:13 PM
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could be the PCM is ****ed up...happend to mine. Got it tuned and walla fans came on.
Old Jul 24, 2008 | 10:42 PM
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You might find some info you can use, here.
Old Jul 25, 2008 | 02:14 PM
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coolant temp sensro in the water pump??? or relays? or fuses?

do the fans come on when direct power is on? have you jumped the relay? if you jump the relay and they come on, then it's not wiring/fans...it's pcm related.
Old Jul 25, 2008 | 10:51 PM
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A stock tune turns on fan 1 at 215 deg F and fan 2 at 240 deg F and that is hot. In 95 GM used 3 relays to turn on the fans. relay 1 provides power to the left fan. relay 2 provides power to the right fan. And relay 3 will direct left fan ground through the right fan motor while the left fan (relay 1)is on and redirect the ground around the right fan when the right fan (relay 2)starts. Ohm the fan motors and CHECK THE GROUNDS.
Good Luck
Big Bubba's Racing
Wired 4 Speed
Old Jul 25, 2008 | 11:16 PM
  #9  
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Stock tune is fan #1 (93 to mid-94 only; or low speed, mid-94 and up) on at 226*F. Fan #2 (or high speed) at 235*F.
Old Jul 30, 2008 | 06:21 PM
  #10  
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so i took the car to the shop the other day to see about the fans cause i couldnt figure it out and they said the fans were running fine and the next thing to try and do is to back flush the system. what does that mean? and how do you do it? i checked the thermostat and it works properly and i took it out and ran the car and saw that the waterpump was working right with coolant moving around in the radiator.
Old Jul 30, 2008 | 07:02 PM
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Is the fan motor still working? just asking because mine ended up being fried.
Old Jul 31, 2008 | 11:30 AM
  #12  
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back flush means cleaning the system in reverse. force water throught the outlet of the water pump until it comes out the inlet...

and i would use prestone's cleaner in there for about 10 minutes before you flush...jsut to remove scale and metal flakes and stuff..

also, while you're at it...switch over to the green stuff. when the coolant settles...if there's an air pocket the dex-cool will NOT protect against corrosion where the green stuff will. the green stuff sticks to the inside and protects while the red stuff is like a waxed car finish...the water beads off and doesnt stick.
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