AC Compressor Power & Contour Fans

F

Fri Guy

15 Year Member

May 10, 2007

435

259

83

Aug 27, 2025

#1

• Aug 27, 2025

• #1

I installed some Contour Fans with the LMR bracket kit and a Delta Current Control 2SPA Fan Controller on my Fox. Fans are kicking on as they should when it reached temp. However, when I turn the AC on the fans are supposed to turn on at low speed and they do not. I double checked my wiring, and all looks good. I have the blue wire tied into the AC clutch 12V power wire.

My system is low on refrigerant due to a leak so the AC clutch won't even kick on. Would that be the issue why the fans don't turn on when AC is turned on? I would think that regardless, it would still get power and turn the fans on. Is there a way that I can check to make sure I'm getting proper power at the AC clutch plug?

Here are the direction to the fan controller I'm running.

http://www.dccontrol.com/2spa.pdf

 

AeroCoupe

lube between the nut and the face. I know my lubes

Founding Member

Oct 28, 2001

5,835

3,966

183

Claremore, OK

Aug 27, 2025

#2

• Aug 27, 2025

• #2

Yes. You need to tie the fan controller AC lead to the pressure switch on the accumulator / dryer. You want it on the constant 12V+ side of the switch. This way the second you turn the AC on the fan comes on and stays on while the AC is in use. Wiring it the way you did will cause the fan to turn on and off with every cycle of the compressor which is hard on it.

 

Reactions: dan50, Shakerhood, General karthief and 1 other person

Mustang5L5

That is…until I whipped out my Bissell

Mod Dude

Feb 18, 2001

43,231

17,914

224

Massachusetts

Aug 27, 2025

#3

• Aug 27, 2025

• #3

The way the AC system in this car is wired is pretty simple. There is a signal to the ECU that the AC is on, but only if the low pressure cutout is satisfied. So if the AC system is low on refrigerant, the low pressure switch opens and nothing downstream of it is satisfied.

In order to trigger the fan, you need to connect to wire 348 which will get 12V once you switch the heater switch to AC

I run into the same issue because my Megasquirt ECU ties into the AC system on wire 73 to the EEC and if the compressor cycles, my fan turns off.

 

Reactions: dan50, Shakerhood and Fri Guy

F

Fri Guy

15 Year Member

May 10, 2007

435

259

83

Aug 27, 2025

#4

• Aug 27, 2025

• #4

Mustang5L5 said:

The way the AC system in this car is wired is pretty simple. There is a signal to the ECU that the AC is on, but only if the low pressure cutout is satisfied. So if the AC system is low on refrigerant, the low pressure switch opens and nothing downstream of it is satisfied.

In order to trigger the fan, you need to connect to wire 348 which will get 12V once you switch the heater switch to AC

I run into the same issue because my Megasquirt ECU ties into the AC system on wire 73 to the EEC and if the compressor cycles, my fan turns off.

Click to expand...

Thanks. So, if my AC was not low of refrigerant and it was working properly then the fans would kick on with the AC switched to on? Would it be best to disconnect where I currently have it tied into and move to 348? I'm assuming 345 LG/P stands for light green/pink? And does that wire run to somewhere closer near the starter solenoid? I have the fan controller mounted right next to it.

 

F

Fri Guy

15 Year Member

May 10, 2007

435

259

83

Aug 27, 2025

#5

• Aug 27, 2025

• #5

Is it the green wire on this plug that I need to tie into?

 

AeroCoupe

lube between the nut and the face. I know my lubes

Founding Member

Oct 28, 2001

5,835

3,966

183

Claremore, OK

Aug 27, 2025

#6

• Aug 27, 2025

• #6

Disconnect the connector and use a test light or multi-meter to find 12V+ when the AC is on (key on as well).

 

Mustang5L5

That is…until I whipped out my Bissell

Mod Dude

Feb 18, 2001

43,231

17,914

224

Massachusetts

Aug 27, 2025

#7

• Aug 27, 2025

• #7

AeroCoupe said:

Disconnect the connector and use a test light or multi-meter to find 12V+ when the AC is on (key on as well).

Click to expand...

This.

Should have 12v when you turn ac on. That’s your trigger

 

F

Fri Guy

15 Year Member

May 10, 2007

435

259

83

Aug 27, 2025

#8

• Aug 27, 2025

• #8

Thanks fellas.

 

Mustang5L5

That is…until I whipped out my Bissell

Mod Dude

Feb 18, 2001

43,231

17,914

224

Massachusetts

Aug 27, 2025

#9

• Aug 27, 2025

• #9

And yes, it should be the green wire, but double check

 

Reactions: Fri Guy and AeroCoupe

F

Fri Guy

15 Year Member

May 10, 2007

435

259

83

Aug 27, 2025

#10

• Aug 27, 2025

• #10

Will check it out this weekend. If it is the green wire does it run along the firewall back towards the drivers side? I’d like to tap into which ever wire is power as close to the starter solenoid as possible.

 

BoostedRed89gt

New Member

Dec 19, 2019

4

0

1

Albany, OH

Jun 15, 2026

#11

• Jun 15, 2026

• #11

Fri Guy - What made you go with the 2SPA versus the S50? Trying to figure out what i need for contour fans on my 93. Old post I know but looking for info I am having trouble finding.

edit: found the information, 2spa basically just relays, S50 pulse with modulated soft start.

 

Last edited: Jun 16, 2026