Wierd lighting-no tail light

[bwilding_2000]

I have a 79 1100 special, and the rear tail light doesn't light up when turned on. The brake light works, but not the tail light. The bulb is fine and the wiring seems to be ok.

What do I check next, the reserve lighting unit, or something else?

[bwilding_2000]

I also forgot to say

I rewired the light through a switch to the battery, so I know that the lighting assembly works. I saw a "light checker" in the schematics for the wiring, but I don't know where it is or what is does.....and now the red headlight/oil light comes on becuase it senses that I bypassed the blue wire running to the rear tail light....

So.... will parts from my 80 1100 work in helping to diagnose the trouble?

[TopCatGr58]

Re: I also forgot to say

Originally posted by bwilding_2000
I rewired the light through a switch to the battery, so I know that the lighting assembly works. I saw a "light checker" in the schematics for the wiring, but I don't know where it is or what is does.....and now the red headlight/oil light comes on becuase it senses that I bypassed the blue wire running to the rear tail light....

So.... will parts from my 80 1100 work in helping to diagnose the trouble?

WHY did you bypass the blue wire to the tail light? Did you first check to see if you have power to that line? That line is HOT when the key is turned on. Do you also have dash/gauge lights? IF not, then it could be as simple as the fuse!? Did you check your fuse by pulling it out and checking continuity vs. just looking at it? These old glass fuse holders can corrode, and break and cause lots of trouble. You may have found that you did the rewiring for naught?

Also, check your oil pressure gauge wire, can get rubbed raw, be grounding and sending false signal to activate RED LIGHT?
T.C.

[HobbyMan]

The light checker is located just forward of the battery under the left side cover. At leas mine is. That connection can come loose or corrode shutting off your tail light and turning on the oil/brake light. Set the wiring back to its stock status and jiggle the connection.