cooling system problem
Thread Starter
Teching In
Joined: Dec 2004
Posts: 41
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cooling system problem i have a 1995 formula and the electric fans do not come on i check it out the best i can without any diagrams but i cant figure it out. It has a switch wiried into it to control the fan that im taking out and tring to make it work properly. the fuses are good and the relays are good i also bypassed the input of the relay to check the circuit from the relay to the fan and the fan comes on so im missing the input to the relay the relay has power to the control side and when you jump that out the fan works it also has power to the input side but im missing the ground signal when it reaches oper. temp. does anyone know where the ground signal comes from and if not maybe anywhere to get a good wiring diagram online????any help is greatly appreciated
TECH Regular
Joined: Feb 2006
Posts: 470
Likes: 0
From: St. Louis
I am having the same problem, I believe my problem is in the pcm because all the relays are working and the sensor in the water pump used for fan operation is new. Here is a web page I found you might want to look at. Go to the section on fan operation there are some schematics that may help you.
http://shbox.com/1/4th_gen_tech2.html
There are two wires at your PCM (look at C100)
One is dark blue and dark green
http://shbox.com/1/fan_schematic_1995.jpg
You can ground both of these from inside the car with a switch too turn the fans on or off manually.
Gound the blue for low fan or ground both for high both fans. This is not a fix but it will save your motor if you get caught in traffic plus it won't affect normal operation of the pcm when that problem does get worked out.
http://shbox.com/1/4th_gen_tech2.html
There are two wires at your PCM (look at C100)
One is dark blue and dark green
http://shbox.com/1/fan_schematic_1995.jpg
You can ground both of these from inside the car with a switch too turn the fans on or off manually.
Gound the blue for low fan or ground both for high both fans. This is not a fix but it will save your motor if you get caught in traffic plus it won't affect normal operation of the pcm when that problem does get worked out.
