Thermo King Super II SR+, Manual, Page: 117 / 145

107
Electrical Diagnosis
CONDITION POSSIBLE CAUSE REMEDY
Run relay will not energize K7 relay defective Remove and test K7 relay
Fault in RRP circuit Test RRP circuit
No power to pin 85 Check for power on 8F circuit
Faulty microprocessor Replace microprocessor
Faulty relay logic board Replace relay logic board
Fuel solenoid will not pull in K7 relay not energizing See (Run relay not energizing)
High pressure cutout switch open Test HPCO
Fault in 7K or 8P circuits Test 7K and 8P circuits
Defective fuel solenoid Test fuel solenoid
Preheat relay will not energize Defective K4 relay Remove and test K4 relay
Fault in 8F circuit Test 8F circuit
Fault in PRP circuit Test PRP circuit
Faulty microprocessor Replace microprocessor
Faulty relay logic board Replace relay logic board
Start relay will not energize Defective K5 relay Remove and test K5 relay
Fault in 8P circuit Test 8P circuit
Fault in SRP circuit Test SRP circuit
Faulty microprocessor Replace microprocessor
Faulty relay logic board Replace relay logic board
Starter will not engage K5 relay not energizing See (Start relay will not energize)
Faulty starter solenoid Test starter solenoid
Faulty starter Test starter
Fault in 8S circuit Test 8S circuit
High speed relay will not energize Defective K2 relay Remove and test K2 relay
Fault in 8F circuit Test 8F circuit
Fault in 10P circuit Test 10P circuit
Faulty microprocessor Replace microprocessor
Faulty relay logic board Replace relay logic board
Unit has no high speed K2 relay not energizing See (High speed relay will not
energize)