Blinker always on

[Croaker]

Greetings ...

I did do a search but couldn't find the answer. I have a 2000 ST purchased a couple of summers ago. With the blinker switch off, the right rear blinker is always on, acting as sort of a running light. It does function properly as a blinker when required. The right front works normally, as does the left front and rear.

The previous owner installed a bunch of electrical accessories, mounting the fuses in the rear, under the tail panel, on the folding plastic cover, and mostly obstucting what I can see. So, before I start tearing things apart, is this a possible "upgrade" - as in, is there something deliberately installed to make this happen? Any thoughts were to start looking? I see a green wire and a blue wire coming out but they both appear unmolested, but I could be wrong and won't really know until I take the fuse block out, and in my experience when this happens it's a shorted wire or burned out bulb, so not sure where to proceed.

Thanks for any help. It's late and I'm tired so I'm just hoping this makes some sense.

Steve

 

[jfheath]

Just to comment that there are two sorts of bulb that share the same body. One has one filament, one has two. These are used for indicator and for tail/stop lights respectively. Here in the Uk I was unable to buy a single filament bulb, so my spares are all the dual filament tail/stop bulbs, which also work for the indicators - the low wattage filament being redundant.

I don't know how Canadian ST1300 lights are wired - but could the use if different bulbs be the reason for the different behaviour ?

 

[Tenmilsocket]

Your front turn signals should also have running lights in addition to the turn signals (dual filament bulbs) which are always on while the rears are only turn signals (single filament). Sounds like you just need a new bulb which is definitely a win when it comes to electrical issues!

 

[Gerhard]

Could it be a filament bulb force in the bulb holder wrong. Not saying how I know this but on a VW Beetle that is possible.

 

[Obo]

Just to comment that there are two sorts of bulb that share the same body. One has one filament, one has two. These are used for indicator and for tail/stop lights respectively. Here in the Uk I was unable to buy a single filament bulb, so my spares are all the dual filament tail/stop bulbs, which also work for the indicators - the low wattage filament being redundant.

I don't know how Canadian ST1300 lights are wired - but could the use if different bulbs be the reason for the different behaviour ?

Edit: sorry, this is for an ST1300

Our rear bulb holders will accept single or dual bulbs but only have wires run for the positive blinker terminal and the ground terminal in the plug. The "running" light terminal in the plug is not normally connected. Like you if we use a dual filament bulb, one filament just goes unused.

 

[SMSW]

As said, you most likely have the wrong bulb installed, but with the additions you mentioned, anything goes. It is also possible the PO reworked the rear indicator lights to serve as running lights (like the front) and is using a two filament bulb in a new socket.

 

[Andrew Shadow]

There two possibilities.

1- the stock wiring has been modified to allow the rear turn signals to operate as running lights as well. Many people have done this. Your problem may simply be that the filament for the running light on the left side is burned out and not working, or it has a single filament bulb installed so the running light is disabled, giving the impression that the right side is defective.

2- If the above is not the case, then somebody has tampered with the stock wiring and has provided a power source to that bulb socket somehow, and below is my reasoning.

As delivered from Honda, there is no power to the bulb when the turn signal switch is in the off position, so there is no power to illuminate the bulb. Likewise, there is no power source for a running light circuit in the stock wiring so again, no power source to illuminate a bulb. Even if it had a dual filament bulb, instead of a single, and one of the filaments was broken and shorting to the other filament, there still is no power supply to enable it to illuminate anything if the turn signal switch is in the off position.

If the turn signal switch was gummed up and sticking and not fully releasing, I would think that this would affect both the front and the rear bulbs on the same side, be it the right or the left side.

I would look closely to make sure that this is affecting the rear only and that the front is not illuminated as well, even if only very dimly, as an indication of a short to power on that side. If it isn't, and it has not been modified to add rear running lights, I suspect some tinkering with the wiring has been done. At a minimum, you will need to access the rear turn signal connectors and bulbs to see what is there.

 

[Larry Fine]

One other possibility is a poor ground on the right front socket.

 

[kiltman]

I have a spare tail section and had a look at the wiring and tried to install a double filliment bulb to the turn signal socket.
The bulbs are not interchangeable. The 2 filament bulb will not lock into the holder and it will not line up with the single positive pole that’s located in the centre of the bulb. The locator bayonets are also different between the two bulbs.
I’ve attached a photo of the taillight so you can see the wiring harness. This is off of a 2001 ABSII Canadian model which is very similar to the US model.
I think you have a wiring issue or as Andrew alludes to, a faulty switch.

 

[klaproth]

If the r/f bulb had a broken filament, it might power up the rear filament if it was laying across the other filament ( in the front bulb).

 

[Andrew Shadow]

One other possibility is a poor ground on the right front socket.

Assuming that is so, wouldn't there need to be a connection between the 12V + of the the front running light and the rear flasher filament somewhere for it to get power when the turn signal switch is in the off position. I don't think that there is.

 

[Andrew Shadow]

If the r/f bulb had a broken filament, it might power up the rear filament if it was laying across the other filament ( in the front bulb).

Because he wrote that the front works properly in both the running and flasher modes, I didn't think that this was the case because I would expect this failure to cause the R/F light to burn at the same light output level in both running and flasher modes.

 

[Larry Fine]

Assuming that is so, wouldn't there need to be a connection between the 12V + of the the front running light and the rear flasher filament somewhere for it to get power when the turn signal switch is in the off position. I don't think that there is.

If the front socket ground is bad, voltage from the front running filament feeds into the front signal filament.

The front and rear signal filaments are always connected together, regardless of the signal switch's position.

 

[Andrew Shadow]

If the front socket ground is bad, voltage from the front running filament feeds into the front signal filament.

The front and rear signal filaments are always connected together, regardless of the signal switch's position.

Agreed, except that that would cause power to be applied to both the front running and turn signal filaments all the time as well wouldn't it? Wouldn't that result in the R/F to always be illuminated at the turn signal brightness level. He wrote that the front running and turn signal both work normally.

 

[klaproth]

Agreed, except that that would cause power to be applied to both the front running and turn signal filaments all the time as well wouldn't it? Wouldn't that result in the R/F to always be illuminated at the turn signal brightness level. He wrote that the front running and turn signal both work normally.

You are correct, but did the OP actually look at the front signal, or just at the reflection/illumination of the light? Or actual intensity? After all, with only one light “lit”, it might be hard to tell if both filaments were “on”.

 

[Andrew Shadow]

You are correct, but did the OP actually look at the front signal, or just at the reflection/illumination of the light? Or actual intensity? After all, with only one light “lit”, it might be hard to tell if both filaments were “on”.

I have no idea. This is why in my original response I did suggest to him that he closely check the illumination of the right front to be sure of its condition, as this would be telling. He has not reported back anything different, so the best that we can do is go by what conditions have been reported. Part of the fun of attempting to do a diagnosis from a distance is that all we can do is go by what is reported, as we can't check for ourselves. He wrote that the right front functions normally in both the running and turn signal modes. If this is indeed the case, that would exclude a broken filament in that position. As this is all that we have to go on for now, we'll have to wait and see.

 

[Al st1100]

maybe the other one is always off I believe its it always on and when the turn signals are on it turns off the dimmer filament and the brighter filament flashes. does it get brighter when the turn signal is on flashing?

 

[Croaker]

Holy cow, lots to digest here. Been working a bunch and haven't had much time to check in here. I appreciate all the kind responses.

The right and left front, as running lights, appear to be equally illuminated, as do the left and right rear. Both sides blink at normal speeds and equal brightness front and rear. The right rear just stays on after turning the signal off.

The switch does feel gummy, so I'll look there, and have a look at the front socket as well. I really don't want to start digging around in the back so, naturally the place where the issue is will be the last place I look.

Thanks to all for helping me get started on sorting this out.