Lights dim when using turn signals or brakes.

[fatbiker]

When I use the turn signals or brakes should the instrument lights, speedometer light, and headlight dim? I recently noticed this while riding one night (I don't normally ride at night) and it doesn't seem right. All the signals flash at their normal speed and the brake light works as it should.

I decided to do a little investigating and I found that all the rear turn signal wires plus the brake wires are connected firmly and in the proper order. Same goes for the front turn signal wires and the headlight wires.

I have an extra LED running/brake light installed so I disconnected it. That didn't solve the problem.

I checked voltage from the battery and with the bike off it reads 12.8 volts; at idle it reads 13.18 volts; and at 2500 rpm it reads 13.80 volts which is low for 2500 rpm but acceptable. I have a brand new UB12220 battery so I checked all the connections and they look good.

I replaced the turn signal relay with a known good one but the problem persists.

Checked all ground wires and they are clean and bolted tight.

Am I missing something or is it normal for the lights to dim?

Thanks in advance!

Fatbiker

 

[jfeagins]

It still sounds like insufficient charging voltage and/or battery reserve capacity, or a combo of some of each, to me.
Did you check voltage at idle WITH all the above electrical stuff turned on? How about both ends of both the positive and negative battery wires?

 

[fatbiker]

I bought a brand new battery to see if it would fix the problem as well as the hot charging issue I've been having. The new battery didn't fix either problem but a cleaning of the starter fixed the hot start problem. I checked and tightened every positive and negative cable I can find but still the problem persists.

 

[Bruiser1198]

Check on doing the crimp fix , it's on here some where and maybe check the ground on your r/r it might need cleaned a little at the ground point. My 96 did the same thing your bike is doing this worked for me but there are more experienced people who will chime also! Later Kurt

 

[Miles Long]

Battery voltage/charging rate appears O.K. - but keep in mind that you are measuring at the terminals. Doesn't mean a damn, if all that good juice is not reaching the draw points!
See what the voltage is at the high and low beam headlight connector, with the bike at idle and with rpms.
Better still, measure at the brown feed wire going to the fuse box. You may have to strip some insulation off the wire to do this. Be careful not to ground out when doing this, or the main fuse will blow.
if you find a significant voltage drop, which you probably will on a bike that old, check the three-wire ignition switch connector (located under the steering neck framework) for corrosion. Clean and reassemble using dielectric grease. If that doesn't help significantly, recondition the ignition switch itself. I believe there is a sticky in the "How-To" forum which describes this process.
Cheers!

 

[fatbiker]

Did the crimp fix a long time ago and that really helped with charging.

You may be on to something Miles. My ignition switch has been acting funny lately and I've been meaning to recondition it lately. I have to switch it on and off a few times to get it to fully engage. I'll clean it as well as the three wire connector then give an update.

Thanks!

 

[jkyle187]

any fix on this?
mine doing same thing

 

[jagco1]

Make sure all the fuses in there holders fit tight. Check main fuse make sure it's tight. Check battery wiring.

 

[95spfldmax]

Did the crimp fix a long time ago and that really helped with charging.

You may be on to something Miles. My ignition switch has been acting funny lately and I've been meaning to recondition it lately. I have to switch it on and off a few times to get it to fully engage. I'll clean it as well as the three wire connector then give an update.

Thanks!

Miles is probably on the right track with the ignition switch. Over the miles, over 100,00 Vmax miles, I've gone through at least three switches over the years..........

And 13.8V isn't bad but 14.2 - 14.4V is better. Might make that little bit of difference.....

 

[jkyle187]

things already done,
crimp fix
new agm battery (fully charged)
Dingy 4 gauge wire set.
cleaned and re lubed all 1157s and 1156s connections
cleaned re lubed flasher switch
cleaned re lubed headlight connection
cleaned re lubed fuses
tighten all grounds.
ignition switched sprayed w/ WD 40(in the key slot)

Dash and headlight flicker(dim) when either turns signal activated while running,not running, kill switch on or off and head light connected or removed. Nothing flickers(dims) with brake lights applied.


I don't think it is a charging issue since it still does it with motor not running...

What next?....

 

[Miles Long]

things already done,
crimp fix
new agm battery (fully charged)
Dingy 4 gauge wire set.
cleaned and re lubed all 1157s and 1156s connections
cleaned re lubed flasher switch
cleaned re lubed headlight connection
cleaned re lubed fuses
tighten all grounds.
ignition switched sprayed w/ WD 40(in the key slot)

Dash and headlight flicker(dim) when either turns signal activated while running,not running, kill switch on or off and head light connected or removed. Nothing flickers(dims) with brake lights applied.

I don't think it is a charging issue since it still does it with motor not running...
What next?....

How about some numbers?
Battery voltage,-not running, idle, 3K rpm
Low, high beam voltage at headlight connector - not running, idle, 3k rpm
Very common to see a whole volt (or more) lost at headlight connector.
Cheers!

 

[jkyle187]

here are some number idle to 3k...any ideas? one analog and digital meter..

 

[jfeagins]

Seems low to me.

 

[alorio1]

I would resolder the crimp fix and follow the brown wire for pinched spot toward leading to the front of the bike. If any of your volt meters have a sharp point on them probe the brown wire up front and see if the voltage drops when you turn on blinkers,,ect.

 

[jkyle187]

here are more consistent numbers:
At battery post
13.05 24hr rest.
13.75 idle
13.86 @ 3k

At headlight terminal (light un plugged)
Switch on low position
13.74 low @ idle
13.61 low @ 3k
Switch on high position
13.46 high @ idle
13.42 high @ 3k

Rear turn signals (switch off & bulbs out and unplugged from wiring harness)
No continuity between any wires and frame or housing.
No continuity between +(brown, green) and -(black) wires.

Brown and green wire from rear (unplugged from signal lights) to headlight bucket (unplugged from console) to frame= no continuity

Brown and/or green wire from rear (unplugged from signal lights) to headlight bucket (unplugged from console) to brown and/or green wire= yest continuity

 

[D-Max2012]

When you press the back brake, nothing flickers or dims out. When you use the turning signals, the dash flickers and / or dims?
Since the brake circuit doesn't use the flasher, I would look at the flasher unit (make sure all grounds are secure). A good test would be to remove all turn signal bulbs and test one at a time in a bulb holder connected to 12v. (remember, to get a bulb holder that is appropriate for the signal type you are running. If you have running lights on and 2nd element for turning, then you would need a holder that has 3 contacts. If your bulb is normally off, until you turn, then your bulb holder would be a 2 contact holder). Also test the connection points inside the bulb sockets, you might have a bad wire from one of your bulb holders, causing a big load on the system. Of course, you would not see a problem till you activate the flasher. If you find all bulbs and sockets to be OK, take a look at the flasher unit itself. If possible, swap it out with a known good one.

 

[Miles Long]

here are more consistent numbers:
At battery post
13.05 24hr rest.
13.75 idle
13.86 @ 3k

At headlight terminal (light un plugged)
Switch on low position
13.74 low @ idle
13.61 low @ 3k
Switch on high position
13.46 high @ idle
13.42 high @ 3k

Rear turn signals (switch off & bulbs out and unplugged from wiring harness)
No continuity between any wires and frame or housing.
No continuity between +(brown, green) and -(black) wires.

Brown and green wire from rear (unplugged from signal lights) to headlight bucket (unplugged from console) to frame= no continuity

Brown and/or green wire from rear (unplugged from signal lights) to headlight bucket (unplugged from console) to brown and/or green wire= yest continuity

Mr. Kyle -
Great job so far. You are trying to solve the issue systematically, eliminating each potential problem point one at a time.
Obviously NO problem with your wiring or switches from the battery to the headlight connection. Those are dandy numbers! Many folks on this forum have resorted to a double relay system to get similar results, since even a slight increase in voltage will result in a brighter headlight.
Your wiring tests confirm the integrity of the signal lights themselves (you could have taken this a step further by checking continuity of the turn signal switch, but this would be a tad more difficult)
So obviously when the signals are in use, the amperage draw is enough to effect the available voltage at the headlight connector, resulting in a dimming light. This would be easily confirmed, by checking the voltage at the unplugged connector while operating the flashers.
Another easy thing you can do - check for an electrical "leak" at the + source for the signal light power - the signal fuse holder. Remove the fuse, and bridge the connectors with your meter set to read amperage. With the key on, there should be virtually no draw on the system (less than 0.1 mA.) If there is, you find out what part of the circuit is the culprit, by unplugging the positive outputs on at a time. These would be the brown wires going to the turn signal relay, the horn, the front brake switch, the rear brake switch, and the tach and temp gauge /neutral light power wire (this one must have to be cut where it connects to the horn power)
If all is well (no leaks) see what amperage is being used when the signals are operating. This should be about 4 amps (2x27watts).
Cheers!

EDIT- Got thinking about this while on a ride today - (sunny and 27 degrees C. - unheard of at this time of year!) Anyway, I may be guilty of not considering the obvious, the simple explanation......there may be nothing wrong with your bike!
First off - what type of bulb are you using in the headlight, and how old is it? The standard bulb is a 55/60 watt. Older bulbs tend to fade with age, resulting in less lumens output. Try a new bulb, see if it dims with flasher operation.
Another thing - you have got exceptionally good voltage numbers at the headlight connector (makes me think the p.o. may have installed relays). PERHAPS the headlight is brighter than normal, when there is no other load on the system, then dims a bit to "normal" with the extra load (flashers)
- As above, see what voltage you get at the headlight connector, with the flashers operating.
Cheers again!

 

[jkyle187]

More stats..
.12 amps across fuse block no flashing,
3.64 (both sides)amps across block fuse flashing active.
Check with different ignition switch. Same thing going on.

Funny stat (well not funny but hmmm)
loosing less than and up to .5 volts measure from headlight (+) positive side connector to battery (-) negative side post while flashers active
loosing 1 volt measured from headlight (+) positive side connector to headlight (-)negative side connector while flashers active.

I will buy a new (H4)bulb...don't think I need it due to above scenario.

What next?

 

[Miles Long]

More stats..
.12 amps across fuse block no flashing,
3.64 (both sides)amps across block fuse flashing active.
Check with different ignition switch. Same thing going on.

Funny stat (well not funny but hmmm)
loosing less than and up to .5 volts measure from headlight (+) positive side connector to battery (-) negative side post while flashers active
loosing 1 volt measured from headlight (+) positive side connector to headlight (-)negative side connector while flashers active.

I will buy a new (H4)bulb...don't think I need it due to above scenario.

What next?

You do seem to have a bit of a leak at the signal fuse circuit - disconnect everything else on it (including the flasher relay), as previously suggested.
See if you can find the source of that .12 amp draw.
HOWEVER - your problem(dimming headlight) is taxing my meager electrical knowledge. My understanding of a bulb's lumens output is a result of voltage available. A 12 volt nominal rated bulb will have a much wider operating range - dimmer when less than 12v., brighter when more .
You state that you are still reading 13v.+ even with the flashers operating.
Could you post a video of your problem? Maybe at night, as well as day?
It will be interesting to see if a new bulb will act any differently.
Other than that, the only suggestion I could make would be to check the flasher switch for continuity and operation, perhaps even bypassing the switch completely, operating the flashers by jumping the appropriate wires.
I suspect you have a service manual and wiring diagrams, but if not, they are both available on this forum.
I haven't seen any responses from the REAL electrician/electronic gurus on this site as yet - only a lot of great suggestions from the laypeople.
You specialists - YOU KNOW WHO YOU ARE - how about helping Mister Kyle out? Please??
Cheers!

edit.....read your last post again. Why not try a temporary negative lead direct from the battery to the headlight connector, install the bulb, see if that helps? If so, trace the ground wire back to it's frame mount, and clean. Better still, add a new permanent dedicated one, just for the headlight.

 

[jkyle187]

No one is helping me because they don't know either...Wiring Gremlins are a pain,,, Id much rather try to *** **** a mountain lion than trouble shoot wiring problems, atleast you know the end result ******* with a lion...
So this is what I have done...lately,
I have installed a new ground to battery to frame (left leg side, in between frame and gas tank there is a wire hook "holder" 10mm bolt) and also permantly grounded the R/R(black wire from R/R) to that spot too.
The long black wire (in the wire harness)on right leg side (the one with 7 crimps coming off of it), removed all crimps and dedicated all crimps to frame ground. 3 on right side to 10mm bolt at faux lock holder 1 on the left side. two ground from taillight and rear turn signal dedicated to the frame ground to seat lock holder 10mm bolt. Installed ground from water temp assembly housing to frame ground also .
Doing all of this so far has gotten me 13.86 at idle and 14.4 @3k on the battery and no voltage drop at the headlight socket now.
the dimming still continues....new flasher did Not help.. I now think it is the LED lights I installed in the speedo and console.. that will be next to test...later....im ready to ride...ill post more. but still would like any input...Thank you Mr Long for all of you help...Tony