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Radiator Fan Voltage

3K views 15 replies 7 participants last post by  Buddy 
#1 ·
hey everyone, my radiator fan doesn't come on. i'm in the process of diagnosing it and am checking voltages at the various places in the wiring since none of my fuses or relays are bad. there are no codes stored in the car either. using the AC trick (cranking the AC all the way cold and blasting the blower fan on "5") I have 14v going to my fan control module, and 1.7v coming from that to where the radiator fan plugs into it. can anyone shed some light as to what that second plug voltage should be? im pretty sure the fan control module needs to be replaced I just want to make sure.
 
#8 ·
Do me a favor and do this you might be experiencing the same issue I am and trying to track down.

Turn the heating on in your car and turn the EC button off and see if your fan kicks off in low RPM.

Also if you know where your temp sensor is under the front engine cover where the Camshaft solenoid is, unplug the sensor then turn the car on and see if your fan kicks off in full RPM mode.

If your fan does

http://www.slkworld.com/slk-r170-general-discussion/323777-weak-radiator-fan.html

Here is my full post of you want to kinda follow along what I have done to diagnose it. Maybe we have the same issue and can work it out together.
 
#10 ·
decided to go a different route with my radiator fan, im in the process of bypassing the car's system and installing a hardwire switch to the fan, with a voltage regulator to control the voltage (speed) of the fan.

got everything wired in and using a volt meter, confirmed that i am getting 12 volts to the fan, the fan actually comes on but at a very slow speed and then slowly stops. i don't know what's causing it to not run as it should, the only thing i can think of at this point is the gauge of the wiring, we are using 16 gauge for the positive and 14 gauge for the negative. any thoughts and input would be greatly appreciated
 
#13 ·
Just an FYI, I got tired of chasing this gremlin down as well. I ended up buying a variable speed and temp stage flex-a-lite kit, wired it all up, terminated the stock system at the plug of the FAN so I don't throw any codes or lights on the dash and its working great. :)
 
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