FORM NO. 56043071 CMAX
™
28/34ST / I-MAX
™
28/32C, BA 750/850ST, BA 750C -
17
SOLUTION SYSTEM
Solenoid will not
open, no solution
flow in auto mode
(See Figure 3).
Verify scrub
brushes are
turning
See Brush System
Troubleshooting
Symptom 2 (part
A&B).
Separate the wiring
harness connector
that feeds the L1
solenoid (2 wires
Brn & Red/Grn).
Test for 24V or 36V
Test the resis-
tance of the L1
solenoid coil. If it
reads infinity coil
is open. If it
reads x ohms or
less it is shorted
(a good coil
should read 55
ohms 10% for
24V or 128 ohms
10% for 36V).
Check for 24V or
36V (Pos.) from the
Brn L1 harness
feed wire to a
(Neg.) battery
standoff
Replace the L1
solenoid coil if
testing shows it
shorted or open.
Test continuity of
the (Pos.) Brn wire
from the S3 Key
Switch to the L1
solution solenoid.
Repair or replace
defective wiring
Check for 24V or
36V (Neg.) from the
Red/Grn L1 harness
feed wire to a (Pos.)
battery standoff
Test continuity of
the Red/Grn wire
from the A1
board
’
s #7 pin
connection to the
L1 solenoid.
Test for 24V or 36V
(Neg.) from the Yel
A1 board
’
s #3 wire
to a (Pos.) battery
standoff.
Repair or replace
the Neg. solution
solenoid Red/Grn
supply wire.
Replace the A2
speed control
Yes
Replace the A1
control board
Yes
Yes
No
No
Yes
No
Yes
Yes
No
No
Yes
No
TROUBLESHOOTING GUIDE ELECTRICAL
Possible Symptom
1
Solution solenoid valve will not open when in the scrub auto solution mode.
SYMPTOM ONE
Note: Do all testing with the key switch on, scrub deck lowered, solution button enabled and the drive paddle activated
(pushed Fwd or pulled into Rev).
Note 2: Enter the
Service Test Mode Program
in the Electrical System manual section, for
alternate
machine troubleshooting procedures.