Can’t find fuse for lights

Danpoet

Member
Joined
Apr 19, 2023
Threads
2
Messages
13
Yardman 13AT604G755 I haven’t been able to locate the fuse for the lights. I did find the 20 amp starter fuse behind the dash panel. The manual (770-10448d) says “the other fuse is mounted to the inside of the frame, behind the battery”.
I pulled the battery, and the only thing that I found mounted to the frame, was the starter solenoid. I removed it to double check for a fuse, but found none. I checked for 12v with my meter grounded to the frame, and couldn’t find 12V on the switch assembly harness at all. The mower does start and run, however.
I removed the switch, and ohms checked the L to A2 position on the switch. It read 0 ohms. The B to A1 switch position is 0 ohms in the start (spring loaded) position. The schematic shows a 20 amp fuse for the lighting on the ground side (green wire) of the lights.
I can’t find this fuse anywhere.
The light switch connector is melted and charred, and looks like it had a lot of current going through it.
Turning the key to the lights position at the input light connector with the motor off, is 0 V.
I don’t get 12V on the input light connector going to the lights either with the motor running. I also moved the light switch back to the lights position while it was running , and got 0 Volts.
 

Danpoet

Member
Joined
Apr 19, 2023
Threads
2
Messages
13
I ohmed the green wire from the G terminal of the starter switch to the green wire grounded through the bolt on the solenoid at the rear of the mower. It read 0 ohms.
I connected my battery charger to the wires for the lights. They both came on when I applied power.
I added a 20 amp inline fuse immediately before the lighting connector at the Geo t of the mower.
I started the mower, and the lights didn’t come on.
I turned the starter switch to the light position, and they didn’t come on then, either.
i checked the fuse, and it was blown.
Any troubleshooting ideas would be greatly appreciated at this point.
 

Danpoet

Member
Joined
Apr 19, 2023
Threads
2
Messages
13
Autocorrect changed my comment about
the lighting connector. It was supposed to read: at the front of the mower.
 

Danpoet

Member
Joined
Apr 19, 2023
Threads
2
Messages
13
I also replaced the lighting connector, as the terminals were charred and burnt.
 

Rivets

Lawn Royalty
Joined
Mar 11, 2012
Threads
54
Messages
14,562
Check DCV going to the lights from the key switch. Should be 12+ VDC. If zero your key switch may be bad or bad A2 connection. If you have voltage check for voltage on the second wire coming off the other light. According to the wiring diagram it looks like the lights are wired in series. (I haven’t seen series wiring on headlights in 2 years, but anything is possible). You said lights worked, so I would wire a jump lead to ground from the second light. Hope this makes sense.
 

Danpoet

Member
Joined
Apr 19, 2023
Threads
2
Messages
13
Check DCV going to the lights from the key switch. Should be 12+ VDC. If zero your key switch may be bad or bad A2 connection. If you have voltage check for voltage on the second wire coming off the other light. According to the wiring diagram it looks like the lights are wired in series. (I haven’t seen series wiring on headlights in 2 years, but anything is possible). You said lights worked, so I would wire a jump lead to ground from the second light. Hope this makes sense.
 

Danpoet

Member
Joined
Apr 19, 2023
Threads
2
Messages
13
I wired a 12v bulb to where the fuse holder was added. Started the mower, and no light yet. However, when I change the switch to the light position, the bulb lights up, indicating a short. I wiggled some harnesses around, but the short remains.
Any ideas as to the most likely culprit?
 

Danpoet

Member
Joined
Apr 19, 2023
Threads
2
Messages
13
The key switch is inaccessible normally, because it’s behind the gas tank.
 

Danpoet

Member
Joined
Apr 19, 2023
Threads
2
Messages
13
The key switch is inaccessible normally, because it’s behind the gas tank.
The bulbs are wired in parallel. Blue wire to one side of the bulb, green to the other side.
 

Rivets

Lawn Royalty
Joined
Mar 11, 2012
Threads
54
Messages
14,562
Normally the green wire would be ground. Are you saying that you have two wires to each bulb, one blue and one green? Are you saying that you wired the fuse into the green wire? Are you saying the lights only come on when you turn the switch to the lights position with the engine running? If so I would say that you solved your problem, as the lights should only come on with the engine running. Sorry for the questions, but I’m not there to see what you have.
 
Top