AC wire hook-up for electric fan

[rolandj]

I have finished installing new Be Cool rad and elecric fans what a difference. The only thing left it the wire for the fan when you turn ac on. I know it the wires by the compressor. My question is i assume i have to test it and hook that wire to the wire that is positive?

 

[wizwrath]

Depends on which fan controller you went with, but most kits are the positive side to trigger the fan on. If you didnt go with a fan controller, I highly recommend one, I've had good results so far with the Flex-a-lite electronic ones.

 

[rolandj]

Depends on which fan controller you went with, but most kits are the positive side to trigger the fan on. If you didnt go with a fan controller, I highly recommend one, I've had good results so far with the Flex-a-lite electronic ones.

What do you mean by the fan controller?

 

[Mustang5L5]

What do you mean by the fan controller?

How are you operating the fans? I assume with relay or controller?

Some controllers use either negative or positive input or have a separate standalone A/C turn on wire.

If it's a relay only, the problem with tapping the relay into the a/c coil is that when you turn on the fan by the normal method, it will try to activate the ac coil as well, so you need to wire in a diode to stop the flow from relay to a/c coil, but allow it to travel from ac coil to the relay

 

[Chrome_Rust]

I just tapped into the wires going to the clutch, before the connector that the pigtail plugs into. turn the car on, start the A/C, and probe the wires til the fan turn on. you have a 50% chance of getting it right the first time....

 

[rolandj]

my fans have a thermostat w relays and a seperate relay for the ac. I guess I can probe wires by the clutch and find out which one it goes to I assume it is the positive one

 

[jrichker]

Post the year of your car and the wire/stripe colors. One wire is ground and the other is the clutch power.

Diagram courtesy of Tmoss & Stang&2birds

See the following website for some help from Tmoss (diagram designer) & Stang&2Birds (website host) for help on 88-95 wiring http://www.veryuseful.com/mustang/tech/engine/ Everyone should bookmark this site.

Ignition switch wiring
http://www.veryuseful.com/mustang/tech/engine/images/IgnitionSwitchWiring.gif

Fuel, alternator, A/C and ignition wiring
http://www.veryuseful.com/mustang/tech/engine/images/fuel-alt-links-ign-ac.gif

Complete computer, actuator & sensor wiring diagram for 88-91 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/88-91_5.0_EEC_Wiring_Diagram.gif

Complete computer, actuator & sensor wiring diagram for 91-93 Mass Air Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/91-93_5.0_EEC_Wiring_Diagram.gif

Vacuum diagram 89-93 Mustangs
http://www.veryuseful.com/mustang/tech/engine/images/mustangFoxFordVacuumDiagram.jpg

HVAC vacuum diagram
http://www.veryuseful.com/mustang/tech/engine/images/Mustang_AC_heat_vacuum_controls.gif

TFI module differences & pinout
http://www.veryuseful.com/mustang/tech/engine/images/TFI_5.0_comparison.gif

Fuse box layout
http://www.veryuseful.com/mustang/tech/engine/images/Mustan

 

[Mustang5L5]

Pretty sure it's a black wire, and another color. The black is ground here.

However, post year to confirm this

 

[93lxtwin]

Should be the black wire with the yellow tracer. I just installed one last week. Works fine when ac is commanded on, if ac is off, works with the
programmed thermostat temp in the controller, or by a manual switch
i installed.

 

[HISSIN50]

Or use lt green/purple feed into the LPCS so the fan doesn't cycle with the compressor. Most aftermarket controllers don't have hysteresis engineered into their switching (like the OEM's do).

 

[rolandj]

I have a 91 gt. I have to look at the color of the wires also to see colors. Thanks

 

[IN2FORD]

I used the wire off of the high pressure switch on the evap. That way the fans are hitting the system the same time the compressor is. My lights would dim quite a bit, even with a 3g alternator when the fans were triggered by the compressor.

Barry