NS_S2K

My A/C fan do not come on when I press the A/C Button, but I hear the a/c compressor click and the a/c works fine and blows cold.

I have the A/C Relocation kit and running AEM EMS V2.

I can't drive w/ the A/C on unless I'm driving 30mph+ so I don't raise the high side pressure and seize and lock up the compressor.

Both radiator fan and condensor fan will come on itself when the coolant temps hit the 199 degree F mark when idling.

I've checked all the fuses under the hood and under the dash related to the A/C and also swapped relays and used a multimeter to check continuity on the relays.

All fuses and relays are in good working condition.

I still cant figure it out.

Damn electrical problems are a PITA!

Should I just wire a switch so I can manually turn on the fans? Or just try to figure out the problem.

The last few days has been hot as hell and kinda of a PITA having to turn off the A/C at the stop light.

Any input in resolving this would be greatly appreciated.

Thanks in advance!

VPS_AP1

I'm pretty sure only the radiator fan comes on when hot, not the a/c fan as well I wonder if having the AEM ECU makes it so both come on at the same time. since the AEM is designed for race cars, race cars don't have a/c.... the radiator fan is controlled by the computer where as the a/c clutch is controlled by the button that askes the computer to turn it on and I'm wondering if it just loops the circuit through the AEM ECU so its still functional but doesn't signal the fans to come on.... if you could get the diagram for inside the AEM ECU I could give you a definite answer. because when the ECM receives a demand for cooling from the A/C system, it delays the compressor from being energized, and enriches the mixture to assure smooth transition to the A/C mode(I doubt the AEM does that).... ask some people who have the same ECU if they have the same problem... good luck.

NS_S2K

Both fans are supposed to come on when the a/c button is on.

Both fans are supposed to come on when the coolant temp hits around 199 degrees.

I confirmed w/ my mechanic.

Your welcome to test this on your car by pressing the a/c button and also by letting your car idle for a few mins.

I also confirmed w/ my buddy that also has EMS V2 and also boosted.

No fans turn on when the A/C button is on.

So you are right. AEM EMS = RACE CAR = NO A/C

I guess we have to wire up a switch.

Thank you for your input!

NS_S2K

Ok, so I plan on using my Cruise Control Button as my Fan on/off switch.

Since I already have no cruise control I figure this button would be best since there is a light on the button and on the dash that can remind me if the fan is on/off.

Here is the circuit wiring diagram for the cruise control, cooling system and ac system.

Cruise Control Circuit Diagram


Cooling System Circuit Diagram


Heating & A/C Circuit Diagram

NS_S2K

So if i cut the LT GRN wire from the back of the cruise control main switch pin #1 and crimp and run a wire.

Where would i tap it will that enable me to manually switch on/off the fan w/ the cruise control button?

VPS_AP1

I would try to find a way to run it directly to the condenser fan relay since your bypassing all the computers and controllers you just need to tell the relay to actuate and complete the circuit..... but one thing I'm thinking is you might have to find a way to run the other wire on the cruise control switch since it might be running off the cruise control unit (wouldnt work below 25mph or would shut off when you hit the brakes). one thing you could do is find the a/c clutch signal wire at the relay and splice into it and run a wire to the a/c condenser fan relay signal wire that way when the clutch is activated (pushing the a/c button) it would also activate the fan and also turn it off when you push the button off. and you wouldnt need to use another button. but this would only activate one fan not both <---guessing.... idk let me know if this might help you.

NS_S2K

I really want to find a way to use the CC switch. Although it's a 12v source it might not work since I had planned to tap into the blk/yel wire before the condensor and fan relay. That wire is already 12v I used a multimeter to check to see if there was any voltage with the key in the on position.

From what I've read up to this point is I need to wire up a switch to ground in order to have the fans kick on. So the cruise control button will not work since it supplies power.

I had emailed my dad all the circuit diagrams. Since he is a Double E major(Electrical Engineer) he has a schematic for me tomorrow he said that will work.

Once I get everything working I will post how I did it.

Stay tuned.

VPS_AP1

yeah he should be way more help in that area than I could be. good luck tho and i would keep the diagram your dad gives you so that way you can share with other people who have the aem v2 and still want a/c.

NS_S2K

Here is the Fan Bypass Switch schematic my Dad made for me.

I will be staying at Pala Casino this weekend w/ my fiance so I won't have time to wire the switch up until Monday.

I already have part of my dash apart and will put the toggle switch where the VSA button is on the '06+ models.

List of Materials needed. (Radio Shack)

- DPST Toggle Switch
- 18 gauge wire
- 1 rectifier diode rated for at least 1 amp at 12V. Part# 1N4001
- A 56 ohm resistor. Anything between 40 and 80ohms is fine.

Tools

- Wire Cutter
- Wire stripper
- Insulated Connector Crimper
- Pliars
- Flat Head Screwdriver.
- Utility Knife
- 10 mm socket and wratchet
- Permanent Marker
- Small Needle Nose Pliars
- Soldering Iron
- Multimeter
- Heat Gun (Optional, Needed for shrink tubing if you're using it.)

I will update the thread w/ pics of install once I finish.

Thanks for your input VPS_AP1.

VPS_AP1

sounds like you got a plan! get it done and enjoy A/C! glad I could help... kinda lol