rear running light burns out

C

catastrophe

XS650 Addict
Messages
136
Reaction score
0
Points
16
Location
quail valley
I have an 81 xs650. Pamco ignition and stock charging. Regulator/rectifier from mikes. Brake light is hooked to the accessories on my key switch. Cant figure out why everytime:wtf: I ride the rear running light burns out. Brake light still works but running light doesn't. It burns out within 30 min of riding. I have tried different brake lights, same result. Anyone have an idea what's going on.
 
If it's not rubber mounted the vibration will do it. Watch it while the bike is running at various speeds. Maybe an LED bulb will take the abuse? Might want to put a meter on it and check your voltage, you might be overcharging. Which will shortly create more problems $$$$$$.
 
It is rubber mounted and the charging is good. I have checked the ground and it looks good. Its mounted on my sissy bar which is bare metal
 
Inside the plug socket, you could:

Clean the backside of the bayonet hooks, where the bulb posts ride.
Check and/or resolder the contact tits of the bulb contacts.
Slightly stretch the socket spring.
Install one of those bell ringy-dingy things that ward off gremlins...
 
I wasn't aware that the stock key switch had an "Acc." position. If you have an aftermarket switch, maybe the "Acc." terminal isn't the best place to hook the tail light to. I would split it off the headlight power feed. The "Acc." position is usually a setting to run accessories with the motor off, like the radio. It supplies battery power whatever that may be. But ..... it may not be regulated by the regulator. It wouldn't need to be if it's just passing along what power the battery has to offer. In your case, if the battery's being charged while running with, say like 14.5 volts, maybe that's getting fed to the tail light through that accessory connection and blowing the bulb.
 
I agree with Gary. It sounds like you have extra high voltage, perhaps 16 or 17 volts. That causes to high of a current in the bulb and it burns out.

Take a look at the ground connection for the rec/reg. If the ground is corroded or is not connected to bare metal on the frame, the regulator loses regulation and voltage goes up to 17 volts or even higher. Could be a defective regulator also.

Install a permanent volt meter on your bike.........................I wouldn't ride my bike without one.
 
I need one of those, even with the charging idiot lights I have.
 
I like the VDO voltmeter - got one on both my 650 and Virago
:bike:
 

Attachments

  • Vgovoltmeter_2.jpg
    Vgovoltmeter_2.jpg
    149.6 KB · Views: 139
  • VDOvoltmeter.JPG
    VDOvoltmeter.JPG
    51.1 KB · Views: 156
It has an aftermarket key switch. The headlight is also ran off the acc. Not sure why the acc and on position would be sending different voltage. I wouldnt think there would be a voltage regulator on the on position of a key switch. Am I wrong? The battery reads 12.4 to 14.2 when motor is at high rpms. So if I hook it to the on position is that gonna regulate the power to it? Where could I hook it to gurantee only 12v?
 
i had the same problem i/2 mile of dirt road. going through 1157's like crazy. bought lcd of ebay and problem solved. paid about 10 bucks and its great. should have done it a long time ago.
 
catastrophe said:
It has an aftermarket key switch. The headlight is also ran off the acc. Not sure why the acc and on position would be sending different voltage. I wouldnt think there would be a voltage regulator on the on position of a key switch. Am I wrong? The battery reads 12.4 to 14.2 when motor is at high rpms. So if I hook it to the on position is that gonna regulate the power to it? Where could I hook it to gurantee only 12v?
Click to expand...

If volts only go up to 14.2 then voltage is normal. Looks like its more of a vibration problem as others have mentioned. Yamaha used rubber mounting of many components on these bikes for a reason.

LED tail/brake light is a great addition, very durable and use very little current, so it keeps the alternator/charging system happy.
 
Hi cat,
a picture is worth a thousand words and so finally, the answer!
Some masochist hardtailed the thing.
Taking it from vibrator to super-vibrator so it shakes the filament off.
Try a better class of anti-vibration mount for the light and run a ground wire from the bulb holder to the battery ground connection.
 
I am that masochist. As far as vibration knocking that filament off wouldnt the brake light filament break as well. One filament isnt stronger then the other. I have used rubber to mount it and grounded straight to the frame. I have used different mounts in different spots as well.
 
catastrophe said:
It is rubber mounted and the charging is good. I have checked the ground and it looks good. Its mounted on my sissy bar which is bare metal
Click to expand...

A sissy bar probably vibrates much more than a standard fender mount. Just a thought.
The tail light filament stays hot (if you ride with the lights on) so it is more prone to failure
from vibration than the less frequently lit brake light filament.
 
Last edited:
So xs650dl. You have any advice. I have tried rubber mounts and same situation. I also have a friend with the same set up same spot and he had no problems
 

Similar threads

W
Stupid question - brake light on cluster
2 3 4
Replies
70
Views
2K
Wrenchmorethanride
W
N
Odd charging problems on '75 xs650
Replies
8
Views
202
Its been a long time
I
S
Brake light wiring Question 1978 XS 650se
Replies
4
Views
535
Superdriver
S
padge
'83 XS650 Build by padge
Replies
9
Views
928
padge
padge
S
Hissing out of left carb and then bike dies.
Replies
13
Views
819
Boneheads47
B
Back
Top