SMC wiring


Feb 7, 2005
i have search the forum and i have the instructions from smc, but all it says is plug the connector into the other connector and i do not have the whole kit all i have is the control box. i know where the red and black wires go but where does the white and green wires go. thanks for ur help
ok i am wiring up the pump right now and want to make sure i have this right. the red wire goes to the pos. pump wire and the pump gets its ground from the frame. the black wire is for the pressure switch and the white and green are for the low alky sensor.

red--> pump
black-->pressure switch
white--> low alky sensor
green--> low alky sensor

Please hury the sun is goin down fast and the darkness scares me :eek:
ok i am wiring up the pump right now and want to make sure i have this right. the red wire goes to the pos. pump wire and the pump gets its ground from the frame. the black wire is for the pressure switch and the white and green are for the low alky sensor.

red--> pump
black-->pressure switch
white--> low alky sensor
green--> low alky sensor

Please hury the sun is goin down fast and the darkness scares me :eek:
I know this is an old post, but ive been searching to doublecheck my wiring, since I rewired it, and I know this to be wrong. Red and black are power and ground for the pump. White is 12v supply for the pressure switch, green is 12v supply for the low level light. The pressure switch and low level switch both share a common ground, to the frame. White and green both have 12 cant have both going to the positive lead on 1 switch...duh:D
I needed to correct my post after realizing I posted it wrong. There needs to be a post like this, as one doesnt exist anywhere when I search and could be helpful to someone someday.
The red and black are power and ground for the pump.
Green goes to the positive on the pressure switch.
White goes to the positive on the low level switch.
The common pin (ground) on the pressure switch goes to a ground on the frame (I used one of the headlight frame nuts, and a wire soldered to a brass washer..popped the nut off, stuck on the washer and bolted it back down.) The negative coming out of the low level switch RCA plug (this may be a really old system) will also go to the same ground. I just jumped that ground over to the ground, or common pin on the pressure the low level switch and pressure switch both share the same ground. Doesnt have to be this way...its just less clutter.
The pressure switch, like this whole kit I bought used, was a big POS that had been abused. The pressure switch fell apart, and instead of getting another from SMC, I just got one from Its 20 bucks, adjustable and even has a plate showing the pressure setting. I have mine set for 60psi. Its way more durable than the one that originally came with the kit...although I have seen the newer pressure switches from SMC and they are really good. Wish I knew where to buy it. You get the parts the next day, sometimes same day, which is why I went that route.

hope this helps someone:

Step 1- Install alcohol tank

1A: Remove fan and shroud assembly by removing the 2 upper studs and the 2 lower screws. Unplug fan power connector. Lift fan/shroud assembly up and out of the car.

1B: Using the screws on the tank as a guide, mark the shroud at the 2 points where the mounting screws touch. (See figure 1). If you have a front mount intercooler, you will need to move the holes out to the rounded edge, to allow the tank to clear the IC tubing. Using a 3/16" bit, drill two mounting holes in the shroud. Attach the tank to the shroud and tighten the 2 nuts.
(see figure 2) Now Re-Install shroud with tank into car.

Step 2- Drill inlet pipe

2A: Use a marker to draw a line on the lower end underneath side of the inlet pipe where the intercooler hose stops. Remove inlet pipe and clean exterior. Drill a 3/8" hole approximately 2" up from the line you made. (see figure 3) (BE SURE TO DRILL THE LOWER END!) Front mount users- nozzle can be installed on the left or right side of the throttle body end of the inlet pipe, approximately 2" back from where the intercooler hose stops. Clean any shavings out from inside the pipe.

Step 3: Install Nozzle Assembly

Unscrew the nozzle from the elbow assembly. Use a ViseGrip pliers to place the nozzle (with washer) inside the inlet pipe and with the nozzle threads poking through the hole you drilled. Screw the elbow assembly onto the nozzle threads and tighten securely with a 1/2" wrench. You want the open end of the elbow to end up pointing toward the alcohol tank. If the assembly still moves some after tightening....don't worry! Mix up a small batch of JB Quik Weld or another epoxy putty and apply around the elbow on the outside of the inlet pipe. (See Figure 4) As it starts to set, you can use a wet finger to mold it tightly . Let JB Weld set till it's good and hard.
Re-install inlet pipe.. You may now screw in the braided steel line into the brass elbow, tighten with a 7/16"wrench on the line and a 1/2" wrench on the ELBOW. Now screw the other end of the hose onto the tank fitting and tighten with 9/16" and 1/2" wrenches. (Figure 5)

Step 4: Route Wiring Harness

Attach the connectors on the end of the grey cable to the matching connectors on the alcohol tank. Route the cable around the battery, under the coolant tank, and along the passenger side fenderwell. Continue along the firewall and through the hole you use for guage wiring. If you don't already have a hole, you can drill one (use supplied grommet) or poke a hole through the steering column gasket. Use plastic wire ties to keep things neat.

Step 5- Install Speed Control Box

Pull the excess cable through to the inside of the car. Trim the extra length and carefully strip off about an inch of the grey covering. Now strip about 1/4" of the 4 inner wires. Use a straight screwdriver to attach the 4 wires to the 4 terminals on the control box. The wires are connected in this
order: BLACK-RED-GREEN-WHITE. (See Figure 6) There is a RED & BLACK wire pair coming from inside the controller- The RED goes to +12 volts (IGN
TERMINAL) at the fusebox, and the BLACK to an under dash ground. (Use drill and supplied screw) Now mount the control box to the side of the dash, to the left of the center A/C vents.. (see Figure 7) Clean the area well with alcohol and let dry. Remove the backing from the velcro on the box, and press FIRMLY into position. Now run the wiring down and under the dash area.
The clear line needs to tap into a boost source....either tap into the line (under dash) you ran to your aftermarket boost guage, or route the line through the firewall to a boost source. (use supplied grommet) Use the supplied tee to tap into the boost source. Then firmly push the clear line from the speed control box onto the tee, using a drop of super glue on each connection for safety.

Step 6- Fill Tank!

For best results fill the tank with DENATURED ALCOHOL from a home supply store like Lowe's or Home Depot. (around $9 per gallon) You can also use isopropyl (rubbing) alcohol in either 70 or 90% strength. The DENATURED Alcohol works better . For long pump life we recommend using 1/2 oz/tank of an alcohol lubricant such as "Uplon" (part#kl-107) made by Klotz. For a dealer in your area check Klotz Synthetic Lubricants or order from SMC. For a quick test, START THE CAR and then turn the pump speed control dial (top dial) to the 12 o'clock position. ( The "ARMED" green lite will come on) Now if you press the red "TEST" button on top of the control box the system will activate. The pump should run, alcohol will fill the line to the nozzle and the motor should stumble from the spray. This verifies proper wiring. NEVER LET THE PUMP SIT IN AN EMPTY TANK!!!!! IT WILL DRY OUT & KILL IT!!


1: The "Spray On Point" Dial (lower dial) is a MULTI-TURN control that sets the level of boost you want the spray to come on at. The system is factory set for about 10 psi. Turn the dial clockwise to raise the "ON" boost level, or counterclockwise to decrease the "ON" boost level.. You will need to experiment since each car is different.

2: Start with the "PUMP SPEED" dial (upper dial) set between MIN & MAX and make a test pass. If the car bogs or seems to hesitate at WOT, turn it down a bit till it doesn't bog., or increase boost if you are not seeing retard.
So far I've run 23# boost on 93 octane pump gas with a TE-44, Blue Tops, TH DP, Precision FM IC and a 29 degree RACE chip. This netted an11.66 @115 mph.
Good Luck and enjoy the system!