Electrical Help -- 89 Yamaha FZR600

[PaleDSM]

I have been putting some time in on an old 1989 Yamaha FZR that has been stored with no put away prep for the last 5 years. One of the things I am having an issue with is the rear tail light. I installed a newer R1 rear LED tail light in place of the old shattered boxy 89 tail light. The new tail is an integrated turn signal type. Common ground, left blinker wire, right blinker wire, and two wires for the stop and tail lamp.

When the bike is on ACC everything works exactly as it should. As soon as I fire the bike up the left lense goes dark for both brake and tail. Turn signal still works fine. If I hit the engine stop button the left lense goes right back to working like it should.

Any ideas?

[drkramm]

whats the voltage like with the bike running and not running .. maybe a bad generator /voltage regulator

[PaleDSM]

Good point. I didn't have a working multi-meter with me at the garage this past weekend. I will take one with next time I am over. I have heard that the older FZRs are hard on generators. I think this bike has gone through 3 with the previous owner.

[jpalamar]

I was thinking how much defference is the draw in the new tail VS the old assemply. EX my GSXR takes a 12V 24W bulb for the stock turn signals. I put a 13V 5W bulb in it becuase I needed one in a pinch. It looked find and you couldn't tell from looks it was the wrong spec. But it did keep flashing fast as if I had a blown bulb but kept working.

I'm wondering if you have the opposite problem as me and just have too much draw. But if it works before the bike in on, then you should check your generator.

[Reds82]

You said it has two wires for brake and running light as in one wire for brake and one running for each side or just two wires total? If it has them for both sides might have something reversed or such. I doubt it is in the generator the new led tail should generally draw far less but could be wrong. I know yamaha usually runs three wire turns in the front turns not sure about the rear if they do you might have the running light wire connected instead of the blinker wire and over loading the light.

[drkramm]

I was thinking how much defference is the draw in the new tail VS the old assemply. EX my GSXR takes a 12V 24W bulb for the stock turn signals. I put a 13V 5W bulb in it becuase I needed one in a pinch. It looked find and you couldn't tell from looks it was the wrong spec. But it did keep flashing fast as if I had a blown bulb but kept working.

I'm wondering if you have the opposite problem as me and just have too much draw. But if it works before the bike in on, then you should check your generator.

unless theres a dead short the led's would draw far less current


You said it has two wires for brake and running light as in one wire for brake and one running for each side or just two wires total? If it has them for both sides might have something reversed or such. I doubt it is in the generator the new led tail should generally draw far less but could be wrong. I know yamaha usually runs three wire turns in the front turns not sure about the rear if they do you might have the running light wire connected instead of the blinker wire and over loading the light.

if the voltage isn't correct going to it ( bad gen /vr etc) then the led won't turn on