booster fan control
Thread Starter
Heel & Toe
Joined: Dec 2003
Posts: 18
Likes: 0
From: Chesapeake VA
booster fan control
my 86 came with the additional radiator booster fan (the one that mounts on the inlet side of the radiator). It will spin by hand but I have never seen or heard this fan turn on and the standard radiator fan (on the engine side of the radiator) works fine and operates at the proper engine coolant temperatures. My question is, what controls the booster fan (temp sensor?) and when should it turn on and off. If sensor controlled and/or relay operated , where is the sensor and/or relay located. Thanks in advance for your help.
Le Mans Master
Joined: Aug 2000
Posts: 8,838
Likes: 31
From: Australia
Re: booster fan control (C4or54me)
The booster fan is directly controlled by a switch in the head as opposed to the ECM control of the main switch. From memory the switch is driver side between front 2 spark plugs. Short this wire to ground and see if the fan starts.If not you have to check the fan relay for operation / power supply.
If it runs when you ground the wire the switch in the head is shot.Buy a new one that starts the fan sooner (lower temp )Ecklers / MAD /Corvette America etc.
NB the fan comes on late ,like 227 degrees so your engine may not be getting hot enough to switch it on.
If it runs when you ground the wire the switch in the head is shot.Buy a new one that starts the fan sooner (lower temp )Ecklers / MAD /Corvette America etc.
NB the fan comes on late ,like 227 degrees so your engine may not be getting hot enough to switch it on.
Thread Starter
Heel & Toe
Joined: Dec 2003
Posts: 18
Likes: 0
From: Chesapeake VA
Re: booster fan control (rodj)
I grounded the wire and the fan runs just fine. I never have seen my engine temp above about 220 degrees so I expect, as you said, it just hasn't gotten hot enough to turn it on. Thanks for the info!!!
