70
- FORM NO. 56043115 - 34 RST
Wheel Drive System
Testing the Speed Limit Control Potentiometer
1. See Figure 9
. Disconnect the Handle Harness
(H)
from the mating connector located to the left of the squeegee
raise/lower handle.
2. See Figure 8
. Use an ohmmeter on pins 1 and 4 to check the total resistance of the potentiometer. If the
potentiometer is working correctly, the resistance across pins 1 and 4 should measure approximately 100K
ohms.
3. Use an ohmmeter to measure the resistance across pins 2 and 4. If the potentiometer is working correctly:
• The resistance across pins 2 and 4 should measure 100K ohms with the Speed Limit Control Knob rotated all
the way counterclockwise (slow speed).
• The resistance across pins 2 and 4 should measure close to zero ohms with the Speed Limit Control Knob
rotated all the way clockwise (fast speed).
• The resistance values across pins 2 and 4 should change proportionately between 100K ohms to zero ohms as
the Speed Limit Control Knob is rotated between slow and fast speed. Note that any “dead spots” or spikes in
the resistance values could indicate a problem with the potentiometer.
4. See Figure 9
. When you’re done checking the speed limit control potentiometer, reconnect the Handle Harness
(H)
to the connector on the machine.
Speed Limit Control Potentiometer Replacement
1. Turn the key switch off and disconnect the battery pack.
2. See Figure 9.
Loosen the setscrew in the Knob
(AA)
, then remove the Knob
(AA)
from the Potentiometer
(AB)
shaft.
3. Pull the Drain Hose out of the brackets to access the 5/16”-18 Hex Head Screws
(U & Z)
.
4. Disconnect the Handle Harness
(H)
from the mating connector located to the left of the squeegee raise/lower
handle. (This will prevent excessive pulling or stress on the Handle Harness
(H)
and connector when the
Handle
(K)
is swung down to remove the Access Plate
(V)
.)
5. Loosen the bottom left- and right-hand 5/16”-18 Hex Head Screws
(Z)
holding the Handle
(K)
to the machine.
6. Remove the top left- and right-hand 5/16”-18 Hex Head Screws
(U)
holding the Handle
(K)
to the machine, then
swing the Handle
(K)
down to allow access to the bottom Phillips Pan Head Screw
(W)
holding the Access Plate
(V)
.
7. Remove the (2) Phillips Pan Head Screws
(W)
and remove the Access Plate
(V)
and attached Access Panel
Gasket
(X)
from the Handle
(K)
.
8. Note the wire colors and connector locations, then disconnect the three Potentiometer leads from the connectors
in the access area. Note that you may need to cut a cable tie to access the wires and connectors.
9. Note the position of the Potentiometer
(AB)
in the Handle
(K)
, then remove the retaining nut and star washer
and remove the old Potentiometer
(AB)
from the Handle
(K)
.
10. Insert the leads from the replacement Potentiometer
(AB)
through the hole in the front of the Handle
(K)
and
to the access area, then plug them into the corresponding connectors. Replace the cable tie if necessary.
11. Install the new Potentiometer
(AB)
into the Handle
(K)
, then reinstall the star washer and retaining nut.
12. Reinstall the Access Plate
(V)
and attached Access Panel Gasket
(X)
onto the Handle
(K)
, then reinstall and
tighten the (2) Phillips Pan Head Screws
(W)
.
13. Swing the Handle
(K)
back up into position, reinstall the top left- and right-hand 5/16”-18 Hex Head Screws
(U)
, then tighten the bottom left- and right-hand 5/16”-18 Hex Head Screws
(Z)
.
14. Reinstall the Knob
(AA)
onto the Potentiometer
(AB)
shaft, then tighten the setscrew.
