Chevy Tri Five Forum banner
1 - 7 of 7 Posts

·
Trifive Automotive Electrical Wiring Expert
Joined
·
27,084 Posts
You need to connect the fan through a relay powered from the battery or starter solenoid through a fuse. Then control the relay by a temperature switch to ground and powered from an ignition 12 volt source.
 

·
Administrator & Tech Articles
Joined
·
52,763 Posts
Don.....I'm wiring up a fan on mine as well.....What kind of relay and do you get them at Radio Shack?....Also, the size of the fuse will depend on the size of the fan and how many amps it draws-correct?

Also, don't understand this last part: "and powered from an ignition 12 volt source."

If its like a horn relay, you have three contacts....One for 12V, one for switched ground, and one for 12V to the device :confused0006:
 

·
Registered
Joined
·
3,338 Posts
Hey Don, you up to drawing a schematic?
With and without switch to turn on fans with AC...
And make it a sticky...
 

·
Trifive Automotive Electrical Wiring Expert
Joined
·
27,084 Posts
David, you can use a standard automotive relay from most auto parts stores. The coil or control circuit of the relay should be connected to a key-on 12 volt source so the fan will not run after the key is turned off. You will use 4 terminals of the relay. Terminal 30 will be wired to a 25 or 30 amp fuse from the battery, starter solenoid, or horn relay 12 volt distribution point. Terminal 87 will go to the fan. Terminal 85 will go to the key-on 12 volt source. Terminal 86 will be wired to the coolent temp switch in the manifold.
Here is a diagram. Disregard the wire colors.


If you have A/C, you can wire a trinary switch to turn the fan on when the condensor needs more airflow. If you don't have a trinary switch in the A/C system, you can use another relay to control the fan relay from the compressor clutch circuit.
 

·
Registered
Joined
·
817 Posts
David, you can use a standard automotive relay from most auto parts stores. The coil or control circuit of the relay should be connected to a key-on 12 volt source so the fan will not run after the key is turned off. You will use 4 terminals of the relay. Terminal 30 will be wired to a 25 or 30 amp fuse from the battery, starter solenoid, or horn relay 12 volt distribution point. Terminal 87 will go to the fan. Terminal 85 will go to the key-on 12 volt source. Terminal 86 will be wired to the coolent temp switch in the manifold.
Here is a diagram. Disregard the wire colors.


If you have A/C, you can wire a trinary switch to turn the fan on when the condensor needs more airflow. If you don't have a trinary switch in the A/C system, you can use another relay to control the fan relay from the compressor clutch circuit.
this is a good diagram I used an adjustable temp switch available at any auto parts store for 20-30 bucks. this will allow you to adjust the fan turn on temp. there is also a way to put a bypas switch in but i never bothered and i have been doing well with my electric setup. if you have ac you probably should add ht bypass just in case.
 
1 - 7 of 7 Posts
Top