Turn Signals Turning me Crazy

[DGXSER]

Ok, so not that much of a turn involved.

I was workign on Steppenwolfs SG today, he has an issue where the turn signals do not blink unless the throttle is up, and then if he hits the brake light, they stop blinking. Now I found a semi bare wire on the y/g to the flasher, fixed that. No change. We did notice if we tapped the flasher unit on anything, it flashed. Wiggling the wires did not effect it only tapping the flasher itself.

So the assumption is the flasher is bad, although it had been replaced not overly long ago. Got the flasher off my SH, all works perfectly. Brake light and all the turns flash. So we took his flasher to my SH, all worked perfectly, turns flashed not even running.

So now we look at the bulbs. He has a Vetter fairing, front bulb on one side is 1157, the other side is 12V 32/3PC (something close to that) which I look up and it seems to be same as 1157. Backs are 1156, and a 12V 32/PC with 1156 written below it. We did discover one of the rear bulbs the bulb was loose from the base, and it did stop working. But still the right side continued to only flash if the flasher was tapped. Both with the old flasher and the newer one.

So now we got the flasher off my SG. Put it on his bike and it works better. IT flashes as long as the revs are over 2-3k, but still quits when the brake light comes on.

Cleaned up the alternator connection behind the fuse box, improves with my SG flasher, but same deal with either of his.

So, why would it work perfectly with the SH flasher (which is a different unit)? Why would it work better with my SG unit than with either of his?

Has us both rather perplexed.

[TopCatGr58]

Hey Don,

He probably has more severe pitting of the contacts inside the flasher than your units, so it doesn't flow the current as well, doesn't heat up as well. However, with his units on your bike it seemed to work okay, so that also makes me think that his bulbs are not quite as strong/high watt level as needed also. So...it may be a combo of problems....worn pitted contacts inside the flasher, and also too low wattage of bulbs.

T.C.

[bikerphil]

Yep, try filing the contact points inside the flasher can, that will probably help.

[crazy steve]

Could be a lot of things.....

Those flashers are designed to work within a 'tolerance range', so a combination of factors is likely at work. Less-than-optimum connections (at the lights, switch, maybe even where the lights are connected to the main harness, grounds) can be part of it. Automotive lamps can be part of it; motorcycle-specific lamps have slightly heavier filaments and draw just a bit more power (even though they're rated the same in most cases) so they present a bigger load to the flasher.

I'd go through and clean/tighten all the turn signal connections (don't forget the plug where the switch ties into the main harness as I've had issues with that one in particular), checking for voltage drop across the connections. You're losing voltage somewhere (a little here, a little there, it adds up..), correct that and they should work...

FWIW, I've had no issues with automotive lamps if all the connections are good. If you're still using a OEM flasher, it may be dirty contacts inside that, these can be cleaned with careful disassembly of the flasher.

[DGXSER]

OK, he has to replace on of the lamps, so perhaps we can get an actual 1157 and two 1156 lamps for him. I will have him drop off one of the flasher cans and try opening it to clean the inerds. I was ready to start chasing the R/R till we started swapping parts around and found these odd results.

Did the 81 model flasher need less voltage to operate? It certainly seemed to work much better than the other three 80 model units.

[crazy steve]

...Did the 81 model flasher need less voltage to operate? It certainly seemed to work much better than the other three 80 model units.

They do show a different flasher for the '81 bikes (a square unit, and I've never seen one) so there may be a slight difference...

The '78-80 flashers do need proper voltage to charge the capacitor so they'll flash, maybe the '81 unit is different....

[Jerry]

Many flasher issues are related to bad ground connections. In addition to what has already been said, I would check these items:

Rear turn lights have a ground wire under the fender at the end of the stem. (At least my XJ does.) Remove the nuts and clean these connections.

The ground wire contacts the bulbs inside the assemblies with small metal straps held in place with small Phillips screws. Remove these screws and clean these connections. Seems to be more of an issue on rear lights than front.

Clean the point where the battery ground wire attaches to the frame.

Check the battery cables for any sign of corrosion. Replacing both battery cables will not only help solve turn light problems but will aid in starting and eliminating other electrical gremlins.

I use a can of contact cleaner, not cheap but fast and works well, and fine (400 grit) sandpaper to clean my contacts. After cleaning and assembly I spray the contact area with a battery post sealant, available at most auto parts stores.

Good luck!

FWIW: I run an after-market 2-prong flasher instead of the stock auto-cancelling unit. The stock unit has 3 blades. 2-blade unit will only go in two ways, (center+left or center+right) and only work in one of them. Won't hurt anything if you plug it in wrong. I started using the 2-blade when pulling my small trailer as I didn't want to put the additional load on the stock unit. 2-blade unit works fine. Stock unit also works fine with the trailer, as it turns out. I still run the after-market unit even though it does loose the auto-cancel feature.

Electronic flasher units will also work, draws less power than stock, rely on current build-up rather than heating elements. More consistent flashing at any RPM. Also work if you plan to change to LED lighting. They are more expensive, though, by a few bucks.

[motoman]

The motorcycle specific bulbs with a bit thicker element having more resistance will allow the flasher to break contact and work more correctly. I assume that this may be why my Venturer sigs. have always cycled correctly as the fairing and rear signal lites still have the original bulbs in them. Was gonna replace the bulbs a few yrs. back to brighten up the lit elements, but under the lenses, even tho inner housings were shiney and free of any dust,etc. the bulb bases have a bit of rust around them.........so left well enough alone as I didn't wanna get into replacing the socket bases, etc.

[Jerry]

The motorcycle specific bulbs with a bit thicker element

I switched over to these quite a while back. They may be labeled "RV" or "Truck" or sometimes "Heavy Duty" and are available at Wallyworld or auto parts stores. The regular duty ones do not hold up and can cause some very strange behaviour if one filament falls over the other in the dual-filament series. DAMHIK.