irocman79

iTrader: (5)

Just getting my car put back together and had my car running and drove it around a little and got it up to around 220 and the only the drivers side fan came on is this correct when should the pass side fan turn on. my car is a 89 iroc with 5.7 tpi and dual fans. would just like some info on what temps the dual fans are supposed to turn on. searched through the posts and have found so many different answers i think i am more confused now. Is there a way to make them come on sooner. And what is the normal temp range for third gen camaros

berlin305

iTrader: (2)

if i am correct they should come on around 238 stock. from what i hear.

HCR13

iTrader: (5)

iirc its when the air conditioning reaches a certain pressure? someone with more knowledge will chime in...

irocman79

iTrader: (5)

so the drivers side turns on at 230 or so then the pass side when the ac turns on.

deadbird

The Primary fan is ECM controlled and should turn on around 220°F or, when the A/C is on.
The Secondary fan is turned on via the fan switch in the passenger head if the temperature exceeds 230°F or, when the A/C is on.


Looking a little more. Wiring diagram shows the fan switch closes at 235° and opens at 225°.
That is according to an '87 service manual.

V6 and V8 single fan will have a similar switching temperature.

88IROConv

I'm not sure this is correct. BOTH fans should come on when the A/C is turned on? I thought only the drivers side fan was wired to the A/C pressure switch. Thus it would be the only fan that could come on when the A/C is turned on. Please explain. I agree with the rest of your post.

deadbird

Yes, both fans should be on with A/C. '87 and maybe '88, would be an exception to this.
For the sake of argument (since I'm not positive on the exact year, probably when the switch from MAF to SD happened), I'll say that after '88, the Secondary fan was also tied to the A/C pressure switch, along with being wired to the fan switch.

When the A/C is turned on and the line pressure exceeds 'X'psi, the switch would close to a ground, switching the relay and causing the fan to run. The same pressure switch was also tied to the ECM.

Prior to the above wiring/pressure switch, only a single fan would run during A/C. The A/C pressure switch worked reverse. Once line pressure reached "X"psi, the switch opened, breaking the ground. This sent the call to the ECM to run the Primary fan. If the car was not equipped with A/C or A/C was removed, the blue wire had to be grounded or, the fan would run at key on and never turn off. <-- This is how my 'bird came.

88IROConv

Ok my '88 has an A/C pressure switch as well as a fan switch. My passenger fan runs non stop with the A/C off and the engine cold. So I'm thinking I should unhook these switches one at a time to see which one kills the fan and then replace that switch.

irocman79

iTrader: (5)

which one is the primary fan on a 89 camaro. Right just my drivers side fan turned on at about 220 or little more is that how it should be.

swisscheese

So when the A/C is not full, there is not enough line pressure to switch the relay?

deadbird

Not enough line pressure to close the 'a/c fan pressure switch'. That causes the relay to run the fan(s). In the case of F eng code (if you go by wiring), neither fan should run if there is not enough refrigerant to make the compressor clutch lock up.

Yes, just one fan will run unless the engine gets hotter than 238°F (or the A/C is on, depending on year)

Reid Fleming

iTrader: (2)

Check out my signature for all cooling fan information.