TROUBLESHOOTING GUIDE
3203 SERIES
8-1.0.0
5/22/2003
1 CRANE FAILS TO OPERATE
(ALL FUNCTIONS)
A. Check power to crane - 12v to
ground at upper left power terminal of
pump relay
1. If ok go to B.
2. If not check continuity back to
battery at Tweco and battery connections.
b. If there is power at pump relay (left
side) and no functions are operable the
most likely cause is in the control circuits
(pendant or receptacle).
1. Verify by touching jumper from
hot side of pump relay to left side control
terminal(small) on pump relay. Pump
should run but crane should not move
unless a valve is stuck open. Also test by
jumping from hot side of pump relay to
left side control terminal of hoist down
relay. hoist should operate down.
c. If previous tests are ok, then
remove pendant and check at receptacle on
crane with jumper and test light.
1. Check for voltage from pin "D" of
socket to ground.
i. If not successful, then receptacle
assembly is bad.
ii. If ok, jumper from "D" to "F"
(hoist down), or "D" to "J" (pump). Other
functions can be checked also by probing
receptacle with jumper. See P/N 680065
page 7-6.0.0. Hydraulic functions require
that pump and valve are both activated.
d. If receptacle tests are ok, then fault
is in pendant hot wire. Either a break in
the wire or it is not attached inside of the
pendant (goes to center terminal of
rotation switch from pin "D").
2 HOIST UP, BOOM DOWN, &
EXTEND (OUT) DON'T OPERATE
BUT ALL OTHER FUNCTIONS
OPERATE. PUMP RUNS WHEN
BOOM DOWN AND EXTEND
FUNCTIONS ARE TRIED. THESE
FUNCTIONS ARE TIED INTO THE
ANTI-TWO BLOCK AND CRANE
OVERLOAD SENSOR SYSTEMS.
THE CRANE IS SHUT DOWN WHEN
THE SENSORS OPEN THE
GROUND CIRCUIT FROM THE
FUNCTIONS.
A. Check two-block bail and switch at
end of boom to verify they move freely.
Switch should make audible click when
operated. Try operating crane while
pulling cord out of cord reel to check for
possible bad spots in cord reel slip rings.
b. If the three functions work, check
both Pressure Switch’s by taking an ohm
reading on the two wires comming from
each individual switch. The 2,350 psi
Switch (P/N 320543) has normally open
contacts, so the reading should be the
minimum (“open”). If greater than the
minimum ohm reading is indicated
(usually a dead short), replace the switch.
The 2,500 psi switch (P/N 366032) has
normally closed contacts, so the reading
should be maximum. If less than the
maximum ohm reading is indicated
(usually an “open”) replace the switch.
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