25) MS2 ONLY (MS1 jump to Step 26)
Solder a wire between s12c and JS9, this feeds the stepper motor driver on the MS2 daughter board. Even if
you’re not going to use a stepper idle valve, it is needed to use the outputs for other items,
like tacho, etc, so you might as well fit it now.
DON’T FIT THIS LINK IF YOUR USING AN MS1 (black
40 pinned microprocessor)!! You will blow it up!
26)
Idle valves
: Note, you can use the PWM Idle Valve wiring diagram for boost control on MS2 if you're
NOT using a PWM idle valve, it can also be used to drive a relay).
i
)Stepper Idle Valve (MS2 ONLY): If using an MS2 and a 4 wired idle device then solder
wires from:
a) JS0 to IAC1A
b) JS1 to IAC1B
c) JS2 to IAC2A
d) JS3 to IAC2B
e) Solder components Q4, Q20 and R39 in place. Note, this gives you a programmable output
that can drive a relay e.g. cooling fan on FIdle (Pin 30 of the db37)
ii) PWM Idle Valve:
(MS1 or MS2)
2, 3 wired devices need a TIP122 and mica insulation.
a) Cut the legs of the TIP122 so they are half the length they were as new.
b) Fit a piece of mica insulation under it and using plastic screws bolt it to the heatsink in a
spare position, or bolt onto the case.
c) Solder a wire from the centre pin of Q4 to the pin 1 of the TIP122.
d) Solder a wire from the right of R39 to the pin 3 of the TIP122
(Some installs might connect pin 3 to the bottom of R43, that's fine too.)
e) Ensure D8 is not fitted or remove it if it is.
f) Get an IN4001 (you should have a spare from D2) and install the non banded end into the
right hole of D8 and the banded end to S12.
g) Solder a wire from the non-banded side of the 1N4001 diode to pin 2 of the TIP122.
