March 2008
"3072RT / 3772RT / 3772RT HD" Service & Parts Manual - ANSI Specifications
Page 4-8
PROBLEM
PROBABLE CAUSE
REMEDY/SOLUTION
Throttle, Choke & Glow Plugs
Throttle does not remain
energized
Throttle does not operate
Choke does not operate
Glow Plugs inoperative
Misadjusted Throttle Solenoid (misadjusted
throttle solenoid will result in the failure of the
solenoid) maladjusted
Throttle Solenoid failure
Throttle Relay (located on side of engine)
Failed diode block (Large) located in Upper
Controls box
Failed Throttle solenoid
Choke Solenoid failure
Failed Choke switch
Failed Glow Plug Switch
Failed Glow Plug Relay - located on side of
engine
Failed glow plugs
Adjust throttle linkage
NOTE: throttle linkage adjustment is critical on diesel engine)
Check + and - to solenoid while operating Throttle
Test for 12 volts on RED wire #00 and ORG wire # 225 while
throttle is requested
Power on these wires should = 12 volts on ORG/BLK wire 325
Test and/or replace diode block
Check for Throttle LED on Upper Control board
Replace Throttle Solenoid
Check + and - to solenoid while operating Choke
Try Choke switch on opposite control panel
Check for Choke LED on Lower Controls circuit board
Try Glow Plug switch on opposite control panel,
Check for LED on Lower Controls circuit board.
Test for 12 volts on RED #00 wire and on ORG/WHT wire #124
while operating glow plugs.
Power on these wires should = 12 volts on ORG/BLU wire 224
Check for 12 volts at glow plugs while operating glow plugs.
end Trouble Table
Dual Fuel Engine - LP
Starter inoperative
No Engine start:
Starter operates
Engine runs rough, no
power, poor throttle response
Battery Cables loose or corroded
Key switch not functioning
Starter not functioning
Circuit board relay failed
Propane tank empty or valve closed
Faulty carburetor mounted Propane solenoid
Faulty propane shut off solenoid
Faulty fuel selector switch
Clogged Propane Filter Located under the
propane tank shelf
Vapor withdrawal tank installed
Low engine coolant level
Clogged Propane Filter Located under the
propane tank shelf
Propane regulator malfunction
Clean, tighten cables
Check power to wire #20 at Key switch while cranking
Check power to YEL/RED #220 wire at starter,
Check ground cable to engine bell housing
Check
input
on plug A pin-17, ORG/RED wire #20 on Lower
Controls circuit board
Check
output
on plug B pin-1, YEL/RED wire #220 on Lower
Controls circuit board.
12 volts in - 0 volts out = replace circuit board
Fill tank - open valve
Check power and ground at Proportional solenoid,
Check solenoid operation
Check power and ground at Shut-off solenoid,
Check solenoid operation
Check power to BLU/WHT wire #22 while cranking engine
Turn Off Propane valve before filter inspection
or replacement
Replace tank with Liquid withdrawal type
Check, add coolant.
Turn Off Propane valve before filter inspection or replacement
Replace Propane Regulator
Summary of Contents for 3072RT
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