Ok I have a 91 z28. at this time the secondary fan don't work(missing the fan switch) From everything I have read on here and other sites my primary fan is supposed to come on at 220 right?
It doen't, it kicks on at 238 like the secondary is supposed to and the secondary fan dosen't even work.
Anyone have any ideas what could cause this? is my computer effin up?

 

Mick, how do you know precisely (238 vs 220) when your fan is kicking on. If you're going by your inside gauge, that's not enough proof in my experience. My hunch is that your primary is kicking on at 220 via ECM, unless a previous owner hosed things up. I troubleshot a fan problem (or so I thought) on my '92 until I determined that my gauge reads about 10-15% too high.

Mike

 

Ok, thats makes sense. But how do I trouble shoot that? Is there a way to see at what temp the fan is coming on? And I just fixed a thermostat problem and when I am driving it (according to my temp guage) stays around 180 and I have a 180 thermostat. But when I am stopped or in slow traffic it will climb to the 238 mark and the fan will kick on and cool it to just below 220 then kick off.
any ideas on how to trouble shoot this or opinions?
And where can I find a connector for the cooling fan switch so I can get the secondary fan working agian. I have a new switch but the connector is broke.

 

Stand at front of the car with a heat gun pointed at the thermostat housing, let the car idle until the fans come on. Make sure the HVAC is off (A/C command will tell the secondary fan to come on, defrost counts as A/C).

 

i have the exact same problem on my '88 iroc. I went under the car and grounded the wire that connects to the fan switch to see if the fans would kick on and they didn't. I'm kinda stuck here too. When the key is flipped to the on position should there be current running through the fan switch wire? if so how much? 12v.

 

is there a standard on which side which fan is.example is left fan always primary and right secondary or is it different from what people have might of previous had?..sorry to sidetrack post I am just wondering when both my fans should kick on or if ones out.Car started overheating and spewing.I will check thermo first but need to know info on fans..Thanks

 

Driver side = primary
Passenger side = secondary

Fan on/off temps and conditions are in my sig.

 

Beaner- All the fan switch does is ground the wire when it reaches the right temp. With the key on, grounding that wire grounds its contact at the fan relay sending power to the fan. That should make it run. If it doesn't, check continuity to the relay, and if that's good the relay may be out( as long as the fan really works). Try 12 volts to the fan first to see if it even works then trace backwards