7.15.3 Search and elimination of failures in engine start-up system

Voltage in terminals of AB (GB1 and GB2) in proper operating charge system should be much the same and correspond to generator voltage and make from 13 to 15

7.15.2.4 Simultaneously all working lamps fail to operate on the cab roof, lamps of the sign “Road-train”, air conditioner, dome lamp, window wiper and rear window washer. ) Check fuse 80A operability on the fuse block F3. In case of failure, replace the fuse. b) If fuse 80A operates properly, check the operability of the electric circuit from the fuse block F3 to the fuse block F2.

7.15.3 Search and elimination of failures in engine start-up system

7.15.3.1 Starter makes low rpm (if winter operating conditions are observed) ) Correct possible unfastening or corrosion of power circuit terminals: - on accumulator batteries; - on clutch coupling case (“minus” circuit); - on power circuit breaker QS1; - on starter terminals and starter fixture. b) Test state of charge, level and electrolyte density and state of accumulator batteries (terminal and cap surface cleanness). Charge and carry out maintenance services of AB if necessary. c) If after abovementioned operations have been carried out starter starting rpm have not changed, contact your dealer for starter repair.

7.15.3.2 Solenoid starter switch responds (when it is switched on token sound can be heard), but starter does not rotate: ) If indicating lamp on instrument board operates normally, contact your dealer for starter repair; b) If indicating lamp on instrument board deaden significantly, then perform operations, described in cl. 7.15.3.1.

7.15.3.3 Starter won’t start. The following types of failures and troubleshooting methods:

1. Check starter for operability by means of connection with indicating lamp (indicating lamp for starter test should be 24V) to “ground” by one wire and by another wire one at a time to: - load-bearing terminal; - solenoid starter switch terminal (by turning starter switch key to position “II” with range selector lever set in neutral position). If in both cases indicating lamp: - lights – contact your dealer for starter repair; - won`t light or lights in one of the abovementioned cases make repairs on electrical power supply circuits and start control.

2. Test starter interlock switch S 3 operation with transmission range engaged. Interlock switch have follower in the form of rod with normally closed contacts. The interlock switch is located in speed control mechanism and put into circuit (brown wire) between coil ( 9.2) starter relay 9 (located in SU) and "ground". When transmission range is engaged breaker contacts will unclose, locking engine start. When transmission range selector lever is in neutral position, the control follower won’t have an effect on switch plunger, its contacts are closed ensuring "ground" of coil of starter relay 9 and possibility of engine start-up.

tact; To test breaker S 3 operability perform the following: - remove wires holding block from terminals of switch; - switch on multimeter in “ohmmeter” mode by connecting it to breaker S 3 con-

- set transmission range selector lever in neutral position; breaker contacts should be closed, resistance tends to zero; - set transmission range selector lever in operating position – breaker contacts should be unclosed, resistance tends to infinity; - in case the specified requirements are not met dismount the breaker S 3; - carry out testing of dismounted breaker, - if its nonoperability is confirmed – replace interlock switch; - if its operability is confirmed – adjust interlock switch using adjusting washer.

lows: 3 Check operability of starter interlock system circuits with GB in “on” position as fol-

- Check operability of circuit from a starter relay 9 coil ( 9.2) to interlock switch 3 for which purpose connect an indicating lamp between terminal "+" of AB and switching unit output F to terminal "86" of relay coil ( 9.2), with relay K9 withdrawn, thus: - The led lamp should be on when transmission range selector lever is in neutral position and if circuit under test operates properly; - The led lamp should be off when shifting of transmission range selector lever into “on” position, or, if circuit under test has failures.

4 Check operability of circuits and engine start-up ware, for which purpose perform the following: - remove instrument board side bar; - check operability of starter switch SA9, by connecting an indicating lamp to “ground” with one wire and with another wire to switch terminals one at a time: ) terminals “30”, “19” - green wires (battery disconnect switch should be on); b) terminal “58” - yellow wires (key should be turned into first position); c) terminal "50" - red wires (key should be turned into second fixed position); Indicating lamp should be on in all cases. - check circuits operability and current supply to terminal 9 of starter relay located

in SU:

- connect indicating lamp to “ground” with one wire and with another wire to relay terminals one at a time: ) power terminal “30” b) coil terminal “85” Key should be turned into second fixed position. Indicating lamp (during starter relay test use 24V indicating lamp) should be on in both cases. - Check operability of circuit from a starter relay 6 to solenoid starter switch; WARNING: SET THE TRANSMISSION RANGE SELECTOR LEVER INTO NEUTRAL POSITION. OPERATOR MUST BE IN CAB! - place a bridge between power terminals "30" and "88" starter relay 6 using auxiliary wire as a connector. Start-up of starter and diesel engine start-up should be initiated at the moment (by-passing control and start-up lock circuits). - check operability on starter relay 6; - turn starter switch key into position “II”. Starter relay actuation and engine start-up should be initiated at the moment. During check of operability of circuit from interlock switch to starter relay 9 it is necessary to assure oneself of starter start-up interlock relay 19 – properly operating relay has constantly closed circuit (power contact ( 19.1) 30 and 88).