Holley 02121NOS - Manual (Page 16)

2.10 WOT/Window Switch Troubleshooting- Verifying the operation of the NOS WOT/Window Switch
NOTE: NOS highly recommends that the user NOT change the factory WOT/Window Switch settings. The
WOT/Window Switch should be set at the - 3000 rpm (low) and 6000 rpm (high) - default settings. With the NOS
WOT/Window Switch, these values are adjustable, but altering them is not recommended. The NOS
WOT/Window Switch also has a TPS/Microswitch built into the unit. The default and recommended setting is 4.3 volts.
This setting ensures that the NOS nitrous system will only activate at FULL THROTTLE above 3000 rpm, and that it
SHUTS OFF at 6000 rpm.
NOTE: The NOS WOT/Window Switch needs to be connected to cylinders that fire one after another. In other words, the first
(coil #1 wire) needs to be connected to a cylinder which fires before another. In this case, cylinder #1 (coil 1 wire on
WOT/Window switch) fires before cylinder #3 (coil #3 wire on WOT/Window switch). If these wires are installed
opposite of this, the WOT/Window switch will not activate properly.
1. To verify the operation of the NOS WOT/Window Switch, first remove the 4 screws that hold the cover onto the
WOT/Window Switch box.
IMPORTANT! Disconnect the solenoid control wires! Make sure the nitrous bottle valve is closed!
2. The lower left and top left dials set the maximum and minimum RPM at which the nitrous turns on or off.
Figure 22
3. Set the lower left dial to 1 and lower right dial to 5. Set the upper left dial to 2 and the upper right dial to 5. This sets the
RPM Window to turn nitrous on at 1500 RPM and off at 2500 RPM. Set the TPS left dial to 2 and the TPS right dial to 0.
This sets the TPS to turn on at 2.0 volts or about 1/4 to 1/2 throttle. See Figure 22.
IMPORTANT! Make sure that the nitrous and fuel solenoids are disconnected before proceeding!
4. Verify the RPM operation by starting the vehicle.
CAUTION! EXERCISE EXTREME CAUTION WHILE TROUBLESHOOTING THE WOT/WINDOW SWITCH, AS WORKING
AROUND A RUNNING ENGINE IS EXTREMELY DANGEROUS! SECURE ALL LOOSE CLOTHING AND
ITEMS TO SAFEGUARD AGAINST CONTACT WITH THE ENGINE! ACTIVE NITROUS AND FUEL SYSTEMS
ARE EXTREMELY DANGEROUS!
5. Have an assistant watch the top row of LED lights in the WOT/Window Switch box, while slowly bringing the engine speed
to 1500 RPM. The top left LED (RPM window) should illuminate at or above 1500 RPM.
6. Next, bring the engine speed to 2500 RPM. The top left LED should still be lit while the throttle is depressed approximately
half way. Once all the LED lights illuminate, the NOS system is active. After 2500 RPM is reached, the middle LED
(System Activation) & left LED (RPM) should turn off.
7. If these steps are verified, the NOS WOT/Window Switch is operating normally.
8. Reset the dials to the default settings (3,000 rpm low and 6,000 rpm high) for on and off. Also, reset the TPS to 4.3 volts
(TPS left dial to 4 and TPS right dial to 3). If there are further issues with the WOT/Window Switch, please contact NOS
tech service with any questions.
16