brake light always on....well it seems that way

is it common for the brake light to always be very close to full intensity all the time? When brakes are engaged I do see the slightest bit of increase in intensity but not much at all (hardly noticeable in daylight). Doesn't seem right to me. Note: with the key turned off, and the front brake lever pulled the brake light goes from completely off to on (as it should). Maybe nothing wrong here, but brake lights are important and I'd like it to be obvious to people behind me when I am braking - the very slight increase in intensity concerns me.

1982 XJ650 Maxim

 

The tail light is quite bright for daytime visibility, and the brake filiment is about half-again as bright as the brake filament. If you notice that the brightness increases when the brake lever or brake pedal is engaged, then it's working correctly.
It sounds like the brake light is a bit dim, so I'd recommend cleaning the sockets, and maybe getting new bulbs.

You might have someone run the brakes as you stand about 50 feet back from the bike. The angle that you look at the light from makes a significant differnence in percieved brightness.

 

I would say no. The Maxim should have two 1157 bulbs that are 27 watt for the brake and 8 watt for the tail light, which makes the brake considerably brighter. Check the bulbs as k-moe suggested, and make sure they are the correct number. Could be you have one brake filament burnt out or just not working. Could be someone installed LED bulbs, which many are known to have a poor differential in lumens between the tail and brake light.

Don't think that is normal. With the key off there is no power applied to the signal circuit.

 

thanks k-moe and Rooster.

are you sure Rooster ? when in Nuetral, and the key inserted and in the "off" position, if I pull my front brake - both the neutral light comes on and the braklight comes on. I did install a new fusebox and shore-up all of the connections a few years ago but I didn't change any wiring (other than add a cigarette adapter near my horn to charge my phone while riding ...easy and useful mod utilizing the open connector on the new fuse box XJ4ever sells.
everything electrically works good, headlight, signals, etc.

I'll definitely check my bulb wattages in the light and report back - that could definitely be it - I could have a 27 watter instead of 8 watter in my tail light

1982 XJ650 Maxim

 

Well yes, pretty sure about that as the ignition switch in the "OFF" position should disconnect all power to the three running circuits in the fusebox. If there is power in the signal circuit the horn, rear brake, and flashers would also be operational.

There is a "P" position on the ignition switch, but on the 650 Maxim this should enable only the tail light when that position is selected.

The 1157 bulb should be dual filament with 27 watts for the brake and 8 watts for the tail. So just be sure that is what you have and they are both functioning. I don't have a 650, but from the wiring diagram it looks like the bullet connectors could be swapped illuminating the incorrect filaments, however that would be unlikely as the color code for the wires is yellow and blue so they are easily identifiable.

 

OK I have two dual filament bulbs in my taillight (82 maxim). both bulbs are on with the key and there is an ever so slight increase in brightness when brakes are applied. the side of the bulb says 12V32/3CPB

can anyone with two bulbs in their taillight tell me if both bulbs are supposed to be on with the key?.....or should only one go on with the key and the other with the brake ?

I definitely have something weird going on, been riding it for years because everything works just as it should but here is what is weird........with key off, pulling in the front brake seems to liven up the electrical system, I can blow the horn, switch on the turn signals, even press the start button and turn it over......weird.....then the second you let go of the brake everything is off. I don't know if this is related or not to what I have going on with my rear taillight. All I know is that with the exception of what I have already explained, everything else works perfectly with the electrical system.

 

That should be correct

With the key on both bulbs should illuminate but only the low wattage filament, which is the tail light.
With the brake depressed (front or rear) both bulbs should get considerably brighter as the high wattage filament is illuminated.

This would suggest that the front brake switch is not connected to the correct wires. It is instead connected to a hot wire and consequently when closed routes power to the fuse box. I would start there to verify color correctness for those two wires - two bullet connectors. You should have a Br to Br and a G/Y to G/Y per the Haynes manual. The Br wire should only be hot when the key switch is set to "ON".

Also be sure to check the color coding on the tail/brake wiring as earlier mentioned.

 

thanks Rooster, I will report back.....currently when the key is turned on both filaments in both bulbs are lit. Then with the brakes there is a tiny increase in intensity (and I mean tiny)

 

fixed. I am embarrassed to say what the problem was.....I just kept thinking why would both filaments in both bulbs be lit without the brakes applied? answer....they wouldn't.....the tension spring on the rear brake light switch was too tight, therefore the brake lights were always actuated or on. Go figure that the addition of the front brake would actually make the filaments in the bulbs slightly brighter.
--thank you all for your help

 

----rooster this is what solved it for me, thanks!

 

Yea the two switch are wired in parallel, so the two together will supply just a bit more current to the bulbs making them brighter.

So what about the other issue with the key off and pulling the front brake lever?

 

yeah.......not sure I want to start tearing down to diagnose that since everything works as it should. Although I would like to get some opinions on what it might be based on the symptoms before I start rummaging around with the wiring. There is lots of black tape wrap all around the original wiring.....all of my NEW wiring for my new fuse box and switched out turn signals (the black rubber ones so they would fit inside my hard Yamaha saddle bags) was just at the ends...

 

OK I discovered this electrical oddity while solving a different one.

with the bike in neutral, and the key in the off position. Apply both the front brake and the rear brake at the same time and report what happens. Does the neutral light come on? do the horn and blinkers work ?

I can't believe that my bike is the only one that does this.............

 

ok you inspired me Rooster, I posted about the other problem....I want someone with this same bike to try it. Note the only reason I discovered this is because my rear brake switch was stuck in the actuated position. If it weren't for this I don't think I would have noticed it. You might never apply both the front and rear brakes at the same time with the key in the off position......it's like a weird back door to my electrical system

 

Mine does absolutely nothing...

 

OK, just to clarify. Before the rear brake was fixed when you engaged the front brake the entire electrical system became active. Now that you have adjusted the actuator on the rear brake so that the switch is no longer always closed, does just the rear brake light come on with the front brake only (key off), but the remaining circuits are dead?

 

lol

 

Which is what it shoud do.

@maybe4, you do indeed have an electrical issue. Please keep it in the thread you already started about the brake light. I can merge this one with it if you like.

 

ok merge, thx

 

yes (no headlight though). now that the rear brake switch is fixed you have to 1st step on the rear brake and then pull the front brake lever hard....(I actually hear an audible little electrical click) at which point the neutral light and the rear brake light come on and I can also turn on the blinkers and sound the horn (although it's weak). all during this time you must continue to keep both brakes fully engaged or everything goes dead.

You have to have both brakes engaged and the bike must be in neutral for the neutral light and also the tail light to come on (with the key off), the remaining circuits are not dead (except the headlight....that is dead). if both brakes are not engaged and if the bike is not in neutral, then everything is dead.

 

Hmmmm..... sounds like a new (to me at least) and interesting problem with the ignition safety circuit.

 

It is interesting, I'd love for a few more XJ owners to try this experiment
1. insert key and leave in the OFF position
2. put the bike in Neutral
3. step on the rear brake, then pull the front brake hard. Continue to keep both brakes fully engaged
.......what happens? For me the neutral light comes on, the taillight (and brakelights) come on, I can sound horn and switch on blinkers (the headlight stays off however). Let go of either brake at any time and the system goes dead.

other than this one odd behavior I have no electrical issues on the bike....everything works as it should
wonder if chacal has ever ran into anything like this.....

 

. looking at wiring diagram it looks like your getting voltage from the voltage regulator brown wire via battery and main fuse,
can not explain tail light

 

Specifics matter here, the tail light is not the brake light. Please pull just the front brake (hard as you suggested earlier) and see if the brake light illuminates with the key off.

My best guess is still this:

If the front brake switch is connected improperly (to a hot wire), which looks to be available per the Haynes manual as a red bullet connector then the symptoms would occur. That is, when the front brake is applied the brake light will illuminate with the key off. Then, if the rear brake switch is closed power is routed through the signal fuse to power the remaining circuits.

Also curious as to this statement. Does the key have to be in for the anomaly to occur?

 

Absolutely nothing at all happens if you just pull the front brake with the key off in neutral. Both brakes must be engaged for the brakelight, neutral light etc to come on. I never would have discovered this anomaly if my rear brake switch hadn't been stuck closed (because I never get on my bike with the key off and engage both brakes while in neutral). I do however periodically push-walk the bike around my garage and apply the front brake. Now with the rear brake switch stuck closed, this is exactly how I discovered this behavior.

I'll check the wiring from the front brake switch - it's certainly possible somewhere along the line over the past 36 years somebody connected something incorrectly (especially where wiring is concerned)

The key can be in or out as long as it's in off

 

Thanks for clarifying that.

I suspect that blows the theory of the front brake switch being wired to a hot wire, but visualizing a miswire can be difficult so since it is an easy check it would still be worthwhile. And while you are there do a good visual on the other connectors with potential to miswire (mostly bullet connectors) to verify matching wiring color codes.

Living with the anomaly is likely OK. However, depending on just what is causing it there could be a slight potential that a portion of the electrical system is not properly fused.

 

hook a volt meter to the key and see if it goes hot when this happens.
you could be getting some sort of short from park position and off. park runs the tail light.
your voltage rectifier may be developing an issue

I tried you issue on my bikes did not get your results.

 

i did put a new fuse box in, maybe I muffed something up. I'll do all of those suggestions and report. It's not causing any running issues but it would be nice to know what's causing it

 

It would have to be a huge mistake to cause this issue. I doubt that it was you.

 

.....every light, and I mean every light, got twice as bright when I replaced the fuse box.
I was thinking of converting to LED until I put this new box from Chacal and decided I didn't need to
......very worthwhile to do this as many people have already stated

 

Why do you have your accessory circuit fed that way? It should be fed either straight from the battery, or from the main after the main fuse.
It will work fine so long as it's fed from the right end of the circuit and the current draw is low enough, but it's not the best practice.
You should also have a dummy connector on the output pin for the unused curcuit, or have it disconnected entirely.

 

there are two reasons I didn't want to run my aux straight to the battery. The first is that I wanted the fuse protection and already had the space available in fuse box (so no inline fuse required), secondly I wanted my aux power switched to the key so that if I left something plugged into the cigarette adapter I wouldn't drain my battery. I really only want to be charging my phone (or whatever) while the bike is running.

All I did was pigtail into the large gauge brown (which is the main feed from the harness) to power the other two unused fuse positions. I don't see an issue with this ?

I agree on properly terminating the unused circuit with a dummy connector.

 

The main feed is the largest gauge red wire. It runs throught the ignition switch and then feeds the rest of the circuits.
The brown wire is for the signals.

 

your right, I don't know how I mixed that up......do you think this is worth changing ? I
only have a 4 amp fuse in my aux circuit and the signals run through the main switch anyway.
trying to get my head around if there is a downside to the way I did it

 

The only real downside is for later troubleshooting, either by you or a future owner.
The original harness signal wire should be fine for the potential 14 amps that it could see since it's the same gauge as the main (IIRC).

 

If you want to use switched power I would say you have it right. That is assuming the rear of the bike is the output of the ignition switch and the input to the fuse box. I doubt Yamaha had a lot of consistency on this, but on my 750 Seca the front was the output of the ignition switch and the input to the fuse box.

In the upgraded fuse box the picture resolution is not that great, but it looks like the main and signal lines were reduced in gauge - most notable on the main.

Did you find the opportunity to check inside the head light bucket to verify the correct coloring on the front brake switch?

 

front brake switch is correct, however I think it's my ignition switch. Park doesn't work at all. when in park mode can you activate the brake light and blinkers and horn ?

 

No. You should only have instrument lights and tail light on U.S. spec XJs.

 

Well things seem to just get weirder day by day. While in "P" do you have to engage the front and rear brake as with the other issue? Does the horn work independently in "P"?

So strange, I wouldn't necessarily blame the ignition switch just yet as it is too easy to check with a meter.

Disconnect ignition switch and check:

Key set to "ON" continuity from R wire to Br and L wire
Key set to "P" continuity from R to L only

Pull the 5 fuses check main harness ignition switch mating connector R to Br R to L and Br to L