brian h

I have a 95 z28 and I went out to warm up the car this morning and the temp was almost pegged when i went back out and the fans werent on. Were do i start looking first?

curacaoz28

relays-thermo- wiring- code??- temp sensor

curacaoz28

did u turn the AC on to see of the fan comes on

brian h

Didnt know the ac made the fans come on. Ill try it real quick.

brian h

It made the drivers side fan come on but its not blowing hard.

brian h

Whatever connection turning the ac on and the coolant fans have...as soon as I turned the ac off and put the heat back on within 30 seconds the fans are working again. Kinda weird. What connections do they have so I know what to be looking for? I dont want to over heat it as it still is a low mile car...88000 or so.

RamAir95TA

iTrader: (2)

There is a fairly detailed diagnostic procedure for the cooling fans on www.shbox.com. Might be a great place to start.

Could be wiring, relay, fuse, PCM temp sensor, etc.

77ihwheeler

I was having a similar problem with my 94 I had a shop look at it and they said they fixed it but they still weren't coming on all the time so I just hotwired them to switches in the cabin its a little annoying have to turn them on and off but at least I know that they will come on

Ponch95

iTrader: (5)

Check your wiring diagrahm...IF your driver side O2 sensor is going out it may affect your fans and not turn them on. Had this problem once

95_TA_USMC

iTrader: (4)

take a look at your pcm coolant temp sensor, it may be unplugged, or bad connection, just a suggestion, but you never know, check the wires back into the harness, and also like the other guys said check your relays, and fuses, harness towards the computer something maybe grounding out/or unconnected along the way! just take your time and properly diagnose the situation and let us know. this place is a wealth of knowledge. And shbox is definately one of the best places for info on our cars!

Nads06111

iTrader: (1)

Pull out the fuses when the car is running. Wait a few seconds and put them back in…. it worked for me when I had a similar problem about a month ago.

lol
here
https://ls1tech.com/forums/lt1-lt4-m...dont-work.html

LT1

iTrader: (1)

How long did you have the car running when you saw the temperature go up?

There is a possibility that the gauge temp sensor isn't correctly working, which could mean that your gauge temp sensor reads high but your engine coolant temp (to PCM) is low and fan not turning on.

Verify that your engine temperature (to PCM) is getting hot enough to turn the fan's on.

both fan should turn on low fan speed at 226 degree's
both fan should turn on high fan speed at 235 degree's