Turn signals lit and NO back lights - RESOLVED - FIXED

cjmitch · Jul 10, 2015

Problem...
2005, 1800 motortrike conversion
Started bike and got ready to leave and both turn signal indicators were lit solid, even when the switch was off
All tail lights in the rear were out, Brake and turn, but not the spoiler light it was fine.
All fuses intact, all relays operational

Took off seat and disconnected the blue and red light connectors
Disconnected the Blue connector and the Turn signals for that direction that were lit went out, and operated perfectly on the front of the bike.
Disconnected the RED connector and the Turn signals for that direction that were lit went out, and operated perfectly on the front of the bike.
Reconnected the connectors, and the front turn signals came on solid, like they were originally broken.
Also the cruse would NOT engage, the unit would turn on but would not activate.
I'm thinking that a bulb has blown and a filament has crossed in one of the tail lights.

Well it took 3 days, WED to SAT, but I figured it out. with a little help from the internet.

It seems as though Gl1800's have grounding problems (DUH)
Somewhere I lost a GROUND (grn/Slvr wire) between the C14 connector (under the seat) and the 2 ground wires that supply the rear left and right lights/signals. They split off somewhere in the harness under the seat
As soon as I made a temp jumper everything in the back lit up like a christmas tree.

AND the Cruise started to engage. Somehow the cruise, and the rear lights SHARE a ground connection

During all this troubleshooting, without a diagram I might add. I realized 2 things
1) Honda did NOT put enough effort into the wiring of this bike.
2) if you are doing Ohm out continuity checks you HAVE to remove all of the light bulbs. ( chased THAT rabbit around the hole for 1/2 day)

Some suggested the fix is to jumper the ground pin around the connector (c14) under the seat. YEs but that can be done but it still puts you at the mercy of the bike wiring.
I split the 2 pin connectors that fed the lights with a male/female pass-through adaptor, and tapped off the ground wire with a spade lug, and 10 gauge TEFLON insulated wire, and ran a new hard ground right to the saddlebag BOLT under the seat.

As soon as I order another 2 pin male female connector set I am going to do the same thing for the Left side so EACH side will have a ground.

One thing I must note.
I am so glad that when I got this bike and decided to LED it up, that I opted for a second trailer Isolator to power the lighting.
THIS one thing made it SOOOOOO Easy to separate My wiring from the OEM wiring, as All I had to do was unplug both the isolator plugs, and then bike was back to OEM.
Teflon wire was great also
Another tip. LABEL LABEL LABEL everything you wire

FuzzyWuzHe · Jul 10, 2015

cjmitch said:
Well it took 3 days, WED to SAT, but I figured it out. with a little help from the internet.

It seems as though Gl1800's have grounding problems (DUH)
Somewhere I lost a GROUND (grn/Slvr wire) between the C14 connector (under the seat) and the 2 ground wires that supply the rear left and right lights/signals. They split off somewhere in the harness under the seat
As soon as I made a temp jumper everything in the back lit up like a christmas tree.

AND the Cruise started to engage. Somehow the cruise, and the rear lights SHARE a ground connection

During all this troubleshooting, without a diagram I might add. I realized 2 things
1) Honda did NOT put enough effort into the wiring of this bike.
2) if you are doing Ohm out continuity checks you HAVE to remove all of the light bulbs. ( chased THAT rabbit around the hole for 1/2 day)

Some suggested the fix is to jumper the ground pin around the connector (c14) under the seat. YEs but that can be done but it still puts you at the mercy of the bike wiring.
I split the 2 pin connectors that fed the lights with a male/female pass-through adaptor, and tapped off the ground wire with a spade lug, and 10 gauge TEFLON insulated wire, and ran a new hard ground right to the saddlebag BOLT under the seat.

As soon as I order another 2 pin male female connector set I am going to do the same thing for the Left side so EACH side will have a ground.

One thing I must note.
I am so glad that when I got this bike and decided to LED it up, that I opted for a second trailer Isolator to power the lighting.
THIS one thing made it SOOOOOO Easy to separate My wiring from the OEM wiring, as All I had to do was unplug both the isolator plugs, and then bike was back to OEM.
Teflon wire was great also
Another tip. LABEL LABEL LABEL everything you wire