Check:
- 1. main, and carburetor heater
- 2. battery
- 3. main switch
- 4. neatral switch
- 5. carburetor heater relay
- 6. thermo
- 7. carburetor heater
- 8. wiring (of the entire charging system)
Note: Before troubleshooting, remove the following part (-s):
- 1) battery cover
- 2) rider's seat
- 3) fuel tank
- 4) steering head side covers
- 5) tool box cover
- Troubleshoot with the following special tool (-s).
- Pocket tester: 90890-03112
1. Main, and carburetor heater fuses
Check the main, and carburetor heater fuses for continuity. Refer to "Checking the fuses".
Are the main, and carburetor heater fuses OK?
NO: Replace the fuse(-s).
YES:
2. Battery
Check the condition of the battery. Refer to "Checking and charging the battery".
- Open-circuit voltage: 12.8 V or more at 20°C
Is the battery OK?
NO: Clean the battery terminals. Recharge or replace the battery.
YES:
3. Main switch
Check the main switch for continuity. Refer to "Checking the switches".
Is the main switch OK?
NO: Replace the main switch.
YES:
4. Neutral switch
Check the neutral switch for continuity. Refer to "Checking the switches".
Is the neutral switch OK?
NO: Replace the neutral switch.
YES:
5. Carburetor heater relay
Remove the carburetor heater relay from the wire harness.
Connect the pocket tester (Ω x 1) and battery (12 V) to the carburetor heater relay terminals.
- Battery (+) terminal → Brown/Yellow terminal (1)
- Battery (-) terminal → Sky blue terminal (2)
- Tester (+) lead → Brown/Black terminal (3)
- Tester (-) lead → Black/Yellow terminal (4)
![](https://motoinstruction.ru/img/yamaha/16/122645.jpg)
Does the carburetor heater relay have continuity between brown/black and black/yellow?
NO: Replace the carburetor heater relay.
YES:
6. Thermo switch
Remove the thermo switch from the thermo switch plate.
Connect the pocket tester to the thermo switch lead.
- Tester (+) lead → Brown/Yellow terminal (1)
- Tester (-) lead → Black/Yellow terminal (2)
![](https://motoinstruction.ru/img/yamaha/16/122646.jpg)
Immerse the thermo switch in the water (3).
Check the thermo switch for continuity. Note the temperatures while heating the water with the temperature gauge (4).
Test step | Water temperature | Good condition |
1 | Less than 23±30°C | О |
2 | More than 23±30°C | X |
3 | More than 12±40°C | X |
4 | Less than 12±40°C | О |
Test 1 & 2: Heat-up test
Test 3 & 4: Cool-down test
О: Continuity
X: No continuity
![](https://motoinstruction.ru/img/yamaha/16/122647.jpg)
Is the thermo switch OK?
NO: Replace the thermo switch.
YES:
7. Carburetor heater
Remove the carburetor heater from the carburetor body.
Connect the pocket tester to the carburetor heater.
- Tester (+) lead → Heater terminal (1)
- Tester (-) lead → Heater body (2)
![](https://motoinstruction.ru/img/yamaha/16/122648.jpg)
Measure the heater resistance.
- Carburetor heater resistance: 12 V 30 W : 6-10 Ω at 20°C
Is the carburetor heater OK?
NO: Replace the carburetor heater.
YES:
8. Wiring
Check the entire carburetor heater system's wiring. Refer to "Circuit diagram".
Is the carburetor heater system's wiring properly connected and without defects?
NO: Properly connect or repair the carburetor heater system's wiring.
YES: The carburetor heater system circuit is OK.