89 RS TBI, Single Fan..Ok, What switch provides the signal to the relay, is it the one on the front of the Intake Manifold, or is there another switch on the head, or Radiator...I have tried jumpering the wire off the intake switch, and still get no voltage to the fan wires...All relays are new.....Any ideas, or suggestions will really help....Thank you, Tom

 

The temp switch on the intake is generally the temp sensor for the ECM.On the earlier('83 to '87) single fan factory setups the ECM controlled the fan operation.If there is a switch it will be in the passenger side head between,and just below,the #6 and #8 spark plugs.Unless the motor is up to the temp(factory sets this between 220*F to 235*F)and the the fan is called for you more than likely will not get a signal to the fan relay.
One side note was the fan system working and it stopped or has it not worked since you've had her.And also have you checked all your connections including the grounds.And are you sure the fan motor is good?

 

Well i used a voltmeter to check at the fan wires, there is no voltage, but i have not bypassed the switch on the head, will try that today..I did bypass the one one the intake, and change the relay....It was working when I first got the car, but has since failed...Thank you very much for your help...

 

Well thank you very much...Is there a way to bypass the switchs to see if the motor will get voltage?????????? Im just about throwed by this, have been under the hood all day....

 

ok, you do know where he fan control relay is right? take the greenwire with a white stripe and ground it. that is the simplest way to put in a manual fan switch and will show you if the fan and relay are good.

 

Oh man, thank you..I will try that tomorrow at work...Just ground the green with white stripe, and the fan should run...I should at least hear the relay, and if so, and no go, that means the fan.....What type of amperage rating should the switch have???? Once again, Thanks....Tom

 

Yurn your air conditioning to max.
POZ

 

I have this same problem on my 89 IROC. I was told mine might be the fan relay sensor. Will keep reading this post to help myself also.

Just for future knowledge, where is the fan relay sensor? Going to buy a new one and also buy Royal Purples Purple Ice and Summits 180* thermostat. Where can I buy silicon hoses (ALL HOSES) for an 89 IROC 305 Carb. Please and thank you.