Here is how to hook up the AEM Water/Meth Boost safe output green wire with a relay when using a electronic boost controller for both stock turbo setups and single turbo setups. The AEM progressive controller includes a Boost-Safe output (grounded when active) that activates whenever the system is armed and runs out of fluid or an error code is flashing. The green wire on the controller is the 1.7 amp switched ground.
Let me explain some things so you understand how it works. You need a normally closed relay, or a 5 prong relay with a 87a normally closed terminal. 30 and 87a are connected (normally closed), and when you connect a power and ground signal to 85 and 86 the relay switches to connect 30 and 87, which disconnects 30 from 87a. I have a greddy profec b spec 2 EBC, there is a white and green wire coming out of the EBC that go to the solenoid valve(and at the solenoid valve there is a wire connector which connects the little white wire to a black wire and the little green wire connects to a red wire). The green EBC wire gets 12 volts when you turn your key on, and the white wire gets a ground signal from the EBC that controls the switching on and off of the solenoid which opens and closes to control boost pressure going to the top of the external wastegate for single turbo setups, or to your stock turbos wastegate actuator. The solenoid is setup normally closed with an external wastegate setup, there is no boost pressure going through the solenoid when it is off, so no pressure gets to the top of the wastegate so your boost will be whatever your wastegate spring pressure is if the solenoid is off. The solenoid is setup normally open for our stock turbo setups, there is full boost pressure going to the actuator when it is off, your boost will be lower wastegate spring pressure when the solenoid is off.
The relay will turn off the solenoid (disconnect the white ground wire going from the EBC to the EBC solenoid) when the boost safe output is activated when there is an error code. So if your water/meth pump has a problem, or the water tank is low on water, your boost will be limited which is a good fail safe if you are running high boost on pump gas and water injection, and especially if you have a more aggressive tune which water injection allows for.
Connect ignition power to 85 on the relay (you can connect this to your yellow aem controller wire that is connected to a ignition switched 12v)
Connect the green aem wire to 86 on the relay.
Do not connect any wires to terminal 87 on the relay.
You will need to cut the white EBC wire and connect the white wire coming from the EBC to terminal 30 on the relay.
Connect the white EBC wire (that goes to the EBC solenoid) to terminal 87a on the relay.
My WI controller and EBC are right next to each other so all the wiring was done close together under the dash. You cannot simply connect the green aem wire to the solenoid white ground wire because it will do the opposite of what you want it to do, it will activate the solenoid and send full boost pressure to the top of your wastegate which would result in overboost.
If you have a different EBC, just use a test light to figure out which of the two wires gets 12v with the key on, so then you know which one is the ground wire that gets hooked up to your relay, as described above. My solenoid has a black and red wire at the solenoid, red is power black is the ground wire.
Greddy profec b spec II instructions at
http://www.greddy.com/upload/file/PRofec_Bspec2.pdf
I also hooked up a switch to the orange wire going to the pump, so if I want to turn off the water injection when I turn off the switch it turns off the pump and the boost safe is activated and my ebc solenoid is turned off so I will only boost wastegate spring pressure.