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Front t/signal running light. ( VT500C )

3K views 34 replies 8 participants last post by  "Captain D" 
#1 · (Edited)


Ride today.
Can see the left front running light (in turn signal) is not on.
Found it came back on and stayed on when turned other t/signal to flash.
Later in ride found it off again.
Turned on the t/signal for that side, it flashed, turned the t/signal off and the side marker stayed on.
Found it off again, found that turning on either side t/signal would bring that marker light back on.

Hum...
... that cant be a problem with the bulb could it?
... that cant be a problem in the wireing, could it?
Must be a problem with the controller/flasher... eh?

.

>> later note:
Did not think to look at the rear lights.
 
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#3 ·
On mine I had a corroded socket and the ground was intermittant. Sand paper it clean and change the bulb.
 
#4 ·
..... found that turning on either side t/signal would bring that [left side] marker light back on.
Might try switching bulbs. Btw, the rear signals don't have running lights as the fronts signals do, so forgetting to check the the rear signals isn't an issue. The rear signals do blink, but unlike the front signals, they go dark during the interim.

When you flick on the turnsignal, the low-filament (running light) in the activated side front bulb is shut off. This prevents both filaments from being on in the same bulb. This is done by the thumb lever. In your situation, the sideways motion is probably clearing off the grit temporarily from the running light contacts. It doesn't matter which side turnsignal is activated, both the left running light contact and the right running light contact are scraped off by the sideways motion of the movable contact plate in either direction. (see diagram)

On the left in the diagram below, when the turnsignals are OFF, only the running lights are lit. This is becuz the +12 contact plate is wide enough to span both running light contacts in the neutral position. On right diagram, when you flick the right signal ON, the right running light (low-filament) gets disconnected and shuts off in the same motion. The left side low-filament remains ON by design. Try cleaning the grit off the contacts by spraying electrical contact cleaner. You'll have to separate the left clamshell housing.



Disclaimer ..... do not use the diagram above if you choose to pose as the latest neighborhood expert as you would instantly expose yourself as a fraud. For example, the hi-filament and low-filament contacts in the diagram are shown on opposite sides of the +12 contact plate. In reality, the hi-filament and low-filament are located on the same side of the +12 contact plate. They're just stacked one above the other. Also, there are two +12 contact sources. One for the low-filament and another for the hi-filament as these filaments are on different circuits even though they're on the same bulb.
 
#9 ·
.....
When you flick on the turnsignal, the low-filament (running light) in the activated side front bulb is shut off. .....

On the left in the diagram below, ......
............
Ron,

Great.
Thanks.
I was thinking there might be some controller somewhere (not just A flasher), and that controller is what would turn off the running lite during the t/signal flashing.
Good diagram for explaining things functionally.
Ah, the thumb switch has two sets of contacts, one set for the t/signals and one set for the running lights.
Ah, a problem in the switch on the contact for the left run light would cause the exact symptoms I have observed/described.
So, I will focus my further efforts there.
Thanks Ron.

Dave

.
 
#5 ·
Only diagnosing it will tell!
I`d try a known working bulb, FIRST!
That`s easy enough to swap out, and nearly as easy as spraying electrical contact cleaner into the switch and operating the switch several times to clean it...

There You have my $.02 ;)
Lets RIDE
D


Merry mas
It just ain`t right without Christ!
Merry Christmas
 
#6 · (Edited)
Thanks for comments guys.

I guess my background in troubleshooting industrial equipement is such that I think if understand how it actaully works, how it suppose to function, how the design makes it function, how each componet in the system opperates in the system; then based on observed symptoms can then make better judgment of what is causing the unusuall operation.

Yah, I could just change the left bulb because the running light is not on sometimes.... but the left running light coming back on when activate the right t/signal; that doesnt seem like could be caused by anything in the bulb itself, or the socket, or the wiring at the left bulb. I was already preicting that could not be the problem.

So I was asking if anybody had any good understanding of the various components in the system operated, and what could cause the particular sypmtoms I described.
 
#8 ·
Here is what is involved for the front lights. Switch positions and wiring and connectors. It has to be in there somewhere.
 

Attachments

#12 ·
Yes, I strongly suspect the switch needs a little TLC...
Contacts are dirty &/or worn...
Prolly dirty though...
ALTHOUGH the socket / bulb connection is also suspected ;)
That`s the reason for my suggesting swapping bulb & cleaning the switch...
Good Luck,
D


Merry mas
It just ain`t right without Christ!
Merry Christmas
 
#13 · (Edited)
I guess my background in troubleshooting industrial equipement is such that I think if understand how it actaully works, how it suppose to function, how the design makes it function, how each componet in the system opperates in the system; then based on observed symptoms can then make better judgment of what is causing the unusuall operation.
A film eventually develops over the contact plates, and in cold temps the film hardens like earwax. Flicking the signal's thumb lever side to side does scrape off the glaze to a point.

A more advanced problem is due to the movable contacts having tiny coil springs under them. If sludge gradually works itself under there and hardens, it'll prevent the coil springs from pushing up the movable contact, semi-encrusted as it is (second pic). The coil spring is centered (fulcrum) so the motion of flicking the turnsignal lever sideways does cause a stuck plate to see-saw up at one end temporarily establishing a positive contact if that end is the intermittent contact.



 
#14 ·
A film or glaze eventually develops over the contact plates, and in cold temps the film hardens like earwax. Flicking the signal's thumb lever side to side does scrape off the film to a point.

A more advanced problem is due to the movable contacts having tiny coil springs under them. If sludge gradually works itself under there and hardens, it'll prevent the coil springs from pushing up the movable contact, semi-encrusted as it is (second pic). The coil spring is centered (fulcrum) so the motion of flicking the turnsignal lever sideways does cause a stuck plate to see-saw up at one end temporarily establishing a positive contact if that end is the intermittent contact.



Excellent explanation, Ron!
 
#15 ·
Thanks Ron !

Yah, with understanding the entire system, and with understanding each component of the system, and understanding how each component works in the system.... can then better troubleshoot based on the symptoms.

In this case, based on the observed/described symptoms, I know to focus my attention on the swtich contacts.

Thanks for detailed photo of the switch contacts. Now I will know what to look for when I open up the handlebar control unit, and pieces drop out. har har har
Past experience tells me to open it up over something, like a towel, to catch any thing that fall out.

Thanks again Ron.

(will be a few days untill I get to it. Stuff going on, and suppose to snow next 3 - 4 days anyway.)
 
#20 ·
That switch pictured appears to have gotten HOT!!!
Indeed. Barbecued and caramelized even, but just to stress a difference. Accumulated crud creates resistance. Resistance then generates heat. In that chain of events. But quite unlike other electrical terminals on the bike, female and male blade terminals, or bullet connectors, for example, that don't move back and forth against each other, temporarily scuffing off crud or glaze, where resistance is due to oxidation or frayed wire strands at the crimp. Where heat generated by unwanted resistance exacerbate the resistance making the strands even more non-conductive and tempering individual strands brittle to the point that wiggling the wires might sever a few strands hanging on by their fingertips .....

Unwanted resistance on the turn signal contacts originate from film glazing over the contacting surfaces. The wires on the turn signal contacts are spot soldered to the back side of the contacts and coated with liquid tape. The spot solders are done on the stationary contacts not the movable contacts so there is no flexing at the joint when you flick the turn signal lever left or right. Those spot solder are pristine if you ever had the opportunity to look at them. Although still possible, there is little possibility that the spot solders would fail the way crimps do, that is, originate the resistance. The preventative measure is to periodically spray the turn signal contacts with electrical contact cleaner to prevent any film from reaching the glaze state, but that does always work out the way it should.
 
#22 · (Edited)
Speaking of which.... now that I am confident to focus my attention on the switch, my first step might be to just try sneaking in the straw of a contact cleaner spray into the housing thru the slot there by the thumb lever.
That's worth a try, but see second paragraph. Note: the turn signal contacts in the pic are later year hondas (my Valk). Don't know if they're the same with your '86, but probably or similar enuff.

It's better to separate the left clamshell housing. You can leave it dangling. The clamshell housing doesn't have to be completely removed off the handlebar. Otherwise you have to fumble around with the choke wheel/cable, at least on my bikes. [edit] the two screws that hold the clamshell together are different lengths. Mark one as the front-most, etc.

Then, you want to unscrew the thumb lever assembly and manually flick the movable contact plate farthest to the right or left to gain better access for the electrical contact spray. Even with that though, the skinny straw on the spraycan won't be able to reach the contacts directly.






Remove the thumb lever assembly by taking off two screws (arrows). *Only those two screws.*



Once the thumb lever is removed, you'll see the below. However, since you've gone so far, you might as well pull out the movable/stationary contacts. They lift off as a single unit with retention barbs keeping them together. There's no screws holding them to the clamshell housing. Just be sure not to damage the spot solders. (Not shown in the pic, there's a metal holder for the wires that needs to be unscrewed out of the way to gain enough slack.)
 
#23 ·
I`d apply a little white grease (or color of your choice) to them parts as I reassemble the thumb knobby too...
Merry Christmas


I`m STUFFED!!
Y`all shouldda come eat at our house :D
 
#26 ·
Yes, I like the fact that the switch shuts OFF the running light as the Blinker blinks...
I installed a two filament socket in my rear turns, it does NOT turn OFF the running light when blinking...
I wish it did!

But??
Such is Life!


I`m still Full from yesterdays feasting :D
But I ate a few turkey sandwiches this morning too,
D
 
#27 ·
Yes, I like the fact that the switch shuts OFF the running light as the Blinker blinks...
I installed a two filament socket in my rear turns, it does NOT turn OFF the running light when blinking...
I wish it did!
The low filaments in the rear 1157 bulbs coulda been wired to the corresponding side front signal's low filament to benefit from the front design. I'm supposing you got +12 from a tapping into the nearby brake light's low filament wire (brown wire).
 
#29 · (Edited)
#30 ·
Only two 5mm pan head screws need to be removed to separate the clamshell housing. Then once the clamshell is separated, only two 4mm bolts need to be removed to extract the turn signal switch. 4 bolts total. It ain't a huge job as it may seem.
 
#31 ·
Yeah, IF you spray through the thumb knob slot, it`ll clean away the grease from that mechanism pretty well...
Crud CAN build up there in that grease and cause the switch not to function properly...
Spraying into the "slot" MIGHT get to the contacts, BUT you`ll hafta put a 1/4 can in there to drench everything...
It`ll be to your advantage to do it right the FIRST time!!!

I`ma lookin` for amber LEDs for additional rear turns...

Lets Ride,
D
New year day tradition = RIDE
 
#32 ·
#33 ·
Yes, them are NICE!!!
I added Red strips for brake, and will add strips for turns...
Might fashion an arrow for desired direction??


Lets Ride,
D
New Years Day tradition = RIDE

Join us
 
#34 ·
#35 ·
I do consider all options @Ramie ===>
However, available HondaBuck$ decides the journeys path...

I`ll have additional DTR White LEDs up front, one day too...

Lets RIDE
Join ABATE in your state
D
 
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