dim headlight

[exquized1]

I am having the same issue. I will be watching on how you get yours fixed. I replaced the headlight relay with one from autozone and my light went dim. Not sure if the 79's special had a diode in the headlight relay the new one doesn't. I've also checked the grounds. And Ya driving at night really sucks! I had to follow a Harley just to see. LOL ( Not trying to pick on Brent too much)

[bikerphil]

Could try bypassing the headlight relay to eliminate that possibility. Unplug the relay, jump the red/yel and the blu/blk wires together and the headlight should come on with the key, bike not running. HTH

[yamahansolo]

i was going to try that next. but i need to hurry and get my new seat on...
i also bought a small fuse box with the atc style fuses. i'll put that in too.
the last 2 nights going to work i had the light bypassed to the other brown connector and it was extremly bright! but you can't switch between high and low beacuse i only hooked up the low. the dash lights go through the relay as well right? i think all the reading i have donbe said they do.
hopefully all this will help!

[John]

The dash lights should come on with the ignition switch, and are on a different ciruit than the headlight, and are not controlled by the relay. They are powered by a light blue wire, as is the tail light. They have their own fuse, if I recall. I don't have my schematic right here in front of me.

[XJOK2PLAY]

yamahansolo...

Been an electrician for many years... what I can add...(and forgive me if you already know this), diodes are placed in circuits to allow an electrical pathway to flow in only one direction, like a gate if you will. If they blow, (or aren't present, ie: new relay missing one), you can indeed get some very strange things happening within the circuit.

But the best lesson I learned early on was that whenever the circuit is acting crazy, or doing the impossible... usually it's due to a poor ground / high resistance from a bad connection somewhere within the circuit. (Searching for a ground.)
In house wiring... bad neutral connections are the first place I usually look when I see weird thigs goin' on.

In 12 V. DC... remember, voltage flows OUT of the battery negative, and returns through the positive. (Which always seemed backwards to me for the longest, since I primarily work on AC circuits.) So, if it can't reach the load, (your headlight), through the pre-designed pathway, it can sometimes backtrack through other paths... like bulb filiments, other ground paths in related circuits, etc. Get some crazy stuff happenin' then and can be tough to track down. Add in how many connections in unbelievable places these bike harnesses have, and it can take a while. Hope I haven't bored you too much by tellin you what you may have already known, and hope this helps ya track it down. Most of my hair USED to be brown, instead of grey like it is now! Been doin' this job too many years!!
Good luck.
Regards,
Bob

[yamahansolo]

thanks!
i'm not an electrician but i have shorted out a radio or few... just kidding. only that one time when i was 16... melted the fuse box in my car hahaha

i have cheked the ground and i also bypassed the main headlight positive and i used the ground from the headlight hookup and it works fine. i just think it's odd that the brakes make the light get brighter when it's hooked up to the headlight connector??? i thought the diode was there to make it look like dc instead of ac for the realy to work. i am going to bypass it tonight.

thanks

[John]

If you still want the headlight to be controlled by a relay, you can install a T fitting below the carbs where the oil light switch currently resides, and then reinstall the oil light switch, and use another pressure switch that will close at 5psi oil pressure. The will allow the light to come on only when the engine is running, but it won't stay latched in if the engine dies. The head light will go out then.

[yamahansolo]

no that's not neccesary. i just want there to be no problems anywhere. i have one of the sealed batteries and even when it's 30 f outside it fires right up first try. so even if the light comes on it's ok. but there is stil la problem with the wires somewhere because the dash lights still go very dim until you hit the brakes.
but hey i got my seat installed! it looks great. i can't post pics because the wife went out of town and took both camera's!!! i'll post them in two days...
chris

[skids]

Diode. The later models have the hidden diode. I suspect it makes the "latching relay" function better. If you yank out that relay and use a switch for the relay to the headlight, that issues would be removed. It really is a good idea to be able to switch off the headlight at times anyway...

[DiverRay]

but there is stil la problem with the wires somewhere because the dash lights still go very dim until you hit the brakes.

You just told me the problem!!
Run a ground wire from the FRAME to the headlight ground. Put in in the wire so the original is still used, but you also have the new one. I'll make a bet the headlight starts working!
You probably pulled a wire a little too much last week when you were doing some work, and no longer have a solid ground.

[yamahansolo]

if you go back up and read one of my posts i did that already. i ran a direct wire from the headlight to the ground. i ran it into the back of the plug for the light, this did nothing.

also when i ran a wire from the brown wire to the headlight so i can drive to work i put just a wire from the actual headlight ground to the headlight and the ground works fine.

[yamahansolo]

update,,,,

the cheap autozone relay was part of the culprint... after i took it off and bypassed the realy alltogether it stopped getting brighter when i tapped the brakes.

but it still gets a little dim at idle. i even took the stock brake buls out and replaced them with the big led ones. i also ran an extra led light bar to the brakes only so it would give extra light when i brake but for some reason they light up and stay light even when the brakes aren't being pushed???
maybe one of brake light switches are a little bad and allowing current to go. i am going to hook up and exta clear incandecant bulb in the stock tail light to give more braking power. it's a small 1.5 watt bulb so hopefully it won't light until i actually hit the brakes. if it does light then i am definatly lossing current to the light switch for the brakes.
any ideas?

oh almost forgot i checked the voltz at the headlight and with the bike off it gets only 11.2 or so. but the battery has 12.5 i still need to check with it running... also i swapped out the stock fuse box for a new one and this didn't change anything but at least it's new