Author Topic: Brake light? (Read 1671 times)

jstfkndi · « **on:** February 29, 2012, 11:12:56 AM »

I have read through the posts and have seen many electrical issues and trying to figure my new tail light situation out. I bought a smaller unit that only has two wires coming out of it. They of course are black and red. I have plugged the red into the green yellow and the black into the brown and vice versa. I checked my rear brake switch (which showed continuity when engaged) and nothing happend. Interesting thing is that the light will come on when the key is switch to start, so I know the bulb is good. Tried grounding the green to frame and still nothing changes. Am I supposed to ground the green to the bulb itself? Really not sure how to get this thing to light up when pedal is engaged. I am a complete novice at this and have gone over the diagram again and again, but without the right color scheme, I am having difficulty with it. I know it is something simple, so is there anyone that can help me with an epiphany?? Thanks!

P.S. I have the veins of this thing hanging all out right now as I am trying to get it to turn over electrically. Feel like I have the majority of it all straight except not turn signals hooked up right now. Capping it off til I find some I like, but figured I should mention this lest it be an answer in itself for my dilemna.

bollingball · « **Reply #1 on:** February 29, 2012, 01:04:10 PM »

Does the new light have one or two filaments?

Fritz · « **Reply #2 on:** February 29, 2012, 01:07:46 PM »

Quote from: jstfkndi on February 29, 2012, 11:12:56 AM

I bought a smaller unit that only has two wires coming out of it. They of course are black and red.

What is it? A tail light? A brake light? A combination? Bulb or LED?
First of all, you could measure voltage between Yellow Green and ground while engaging the breaks. It should show about 12V.
Then measure between brown and ground. Should be the same result (with ignition and lights on of course)

If you get the correct results, your new tail light must be the problem.

OldSchool_IsCool · « **Reply #3 on:** February 29, 2012, 01:08:05 PM »

I would expect 3 wires (brake, tail & common ground). Maybe you got a marker light instead of a tail/brake light?

apostrophe28 · « **Reply #4 on:** March 01, 2012, 01:48:44 AM »

+1 (break,tail,grnd) wires.....check out the technical link and look up your wiring diagram

jstfkndi · « **Reply #5 on:** March 01, 2012, 05:36:10 AM »

Ok, thanks. It is a brake light. Has a license plate light, and two filaments. I took it apart to see what I was missing and the bulb has the two metal circles at the bottom and looks tom me like the wires go straight there. Because of the type of bulb it is, i am going to say no on the LED (aren't they a little different looking...never took one out to see)? I will test the wires. What would be the problem with the light if everything tests out? It lights up. Could it just be the wrong type? I bought it off CL from a guy who had it on a 400F, so not sure why it would work for him. Thanks for the tips and I will let you know what I find!

jstfkndi · « **Reply #6 on:** March 01, 2012, 05:46:32 AM »

Also should note that the bike is a 74' 350F. Realize I never posted that and figured I should pending any special informative specs

OldSchool_IsCool · « **Reply #7 on:** March 01, 2012, 06:59:44 AM »

I'm thinking that the metal housing of the light is meant to serve as the common ground. You might wana attach a wire to a screw somewhere on the housing and connect that to the bikes green wire. The bikes brown wire then would connect to the lamp wire that shines a little. The bikes green/yellow wire then connects to the lamp wire that shines a lot.

You'd think that the manufacturer would pop for the 11- cents to add a proper ground wire! Cheap bastards!

bollingball · « **Reply #8 on:** March 01, 2012, 07:06:20 AM »

How do you know it worked for him? Not saying it is bad. But hope you are not going by he said so. The plate light is usually shared with the tail light. I think the two wires are tail and brake and the unit is not grounded. But would need to see it to be sure. More than likely you will need to run a ground to it or remove some rubber that is isolating it from being grounded. Can you post a photo?

Ken

jamesb · « **Reply #9 on:** March 01, 2012, 09:10:13 AM »

i had a cateye tail light it had two wires red and black the red was brake and the black was tail. the case was used as the common ground. like bollingball stated check to see if there is some rubber washers on it that will cause you not to be grounded.

jstfkndi · « **Reply #10 on:** March 01, 2012, 09:20:06 AM »

I am going on his word for it. Saw his garage (his business and it was meticulous), but your point is taken....not certain it worked on his. There is a rubber plate that the light sits on (my guess to keep out moisture) adn when I was taking it apart, I noticed that there is a screw that holds the light bulb in underneath it. Screw will not bottom out, but I am thing with a washer I might be able to try and make that a ground. I can take a pic tonight and try and post it. Not sure how this one is, but most forums you have to reduce the pic, so i will do my best to get one up here

jstfkndi · « **Reply #11 on:** March 02, 2012, 05:26:58 AM »

Pics.

jstfkndi · « **Reply #12 on:** March 02, 2012, 05:29:32 AM »

Experimenting....

jstfkndi · « **Reply #13 on:** March 02, 2012, 05:33:26 AM »

Got the pic thing figured out

jstfkndi · « **Reply #14 on:** March 02, 2012, 05:33:51 AM »

jstfkndi · « **Reply #15 on:** March 02, 2012, 05:37:55 AM »

and this is all I got. The light does ground itself to the fender I realized, so the green is not really useful. I tried wires connected two different ways (g/y to red, g/y to black, brown to red and brown to black. Results were the same. Light comes on. Checked the brake switch again and it has continuity when engaged, but no light? Does it matter that my front brake set up is not altoghether? I don't have any fluid in the front lines and no inside pad, but wires are all hooked. Is it the wrong kind of light?

jstfkndi · « **Reply #16 on:** March 03, 2012, 09:50:07 AM »

Bump for any info

bollingball · « **Reply #17 on:** March 03, 2012, 12:19:13 PM »

jst Instead of checking continuity check for power.See if you have about 12v on the g/y on top of rear fender while you have your foot on the break. Put the black meter lead on a good ground. If you have power you know the problem is back at the light. If no power it is back to the sw. Also check if you have power on the black wire on the rear stop light sw. make sure to have the key sw. on

Ken

jstfkndi · « **Reply #18 on:** March 05, 2012, 05:28:26 AM »

Everything is in line electrically. I guess I am down to trying a new bulb out and need to get my front brake set up and see if that will work too. Good news is, she fired up for the first time since I've had it and she sounds goooood!!! New tires, front brake pad, clean out tank, and get my brake lights working right and another old CB will hit the road!

News:

Author Topic: Brake light? (Read 1671 times)

bollingball

bollingball

bollingball