1977 Tail light lost voltage Brake works fine

Hi All,

My tail light red wire has lost all voltage...the brake light though works fine.
My question is if the red wire goes to the ignition switch how do i test it? Is it as simple as seeing if there is a connection between BLUE and RED?

Help

The main wiring harness connects to a smaller harness going from under the seat to the tail light. The harness might be shorted out or a wire might be disconnected. You can unplug the connectors at the tail light and pull the small harness out to check it.

No offense but did you see my question?

galaxian wrote: Hi All,

My tail light red wire has lost all voltage...the brake light though works fine.
My question is if the red wire goes to the ignition switch how do i test it? Is it as simple as seeing if there is a connection between BLUE and RED?

Help

Hi galaxian,
We'd say yes. When the ignition sw. is ON blue and red is closed according to Clymer manual.

Disconnect the ignition sw. pin connector and test for continuity between blue and red with sw. ON. No continuity = bad sw.

Good Ridin'
slmjim & Z1BEBE

galaxian wrote: No offense but did you see my question?

Hi Galaxian,
Yes however i was thinking there might be an easier solution, e.g. finding an unplugged connector or a frayed wire.

Did that before posting. But thanks for your suggestion. Im not trying to be rude but this site has grown over the years and search does quite work well. I hate wadding through the same questions so i was being as specific as possible.

Slimjim,

I have the switch ON
Put one probe onto the red the other on the blue 1.9 ohms. I didnt pull the wired out of the ignition switch. Does that negate the test?

Yes.
Switch has to be out of the circuit to test continuity between blue & red with switch ON.
If it's like a Z-1 the pin connector is in the headlight bucket..

Good Ridin'
slmjim & z1bebe

Now im getting 7 volts at the tail....not sure what to do about it yet. As far as pulling the pins they are in the pod where the key inserts.

galaxian wrote: Did that before posting. But thanks for your suggestion. Im not trying to be rude but this site has grown over the years and search does quite work well. I hate wadding through the same questions so i was being as specific as possible.

being as specific as possible should imo include make and model of whatever 1977 motorcycle is being referenced.

While it may sometimes be possible to comb through another member's various earlier postings among other threads in an effort to help guess what make and model is being asked about, I suspect that many members who are normally generous toward posting helpful replies will simply pass and move on without bothering to comb.

It's easy to put the information in your signature where it shows in all posted messages, past and future. And the signature may be changed whenever and as often as desired.
If wanting a signature showing information about the bike in posted messages, it's easy to do. Here's how:





Good Fortune!

Mia culpa....Kz1000 1977

1000A? I would back probe the ignition switch connector for voltage. key on. The problem could be the soldered connections inside the Ign switch. assuming it's not a problem with the tail light harness. If the Ign sw tests fine, then I guess you'd have to check the harness.

Edit: I would jiggle or move the pigtail around while probing. and do the same at the tail light harness connector.