Motorcycle Forum banner

1 - 14 of 14 Posts

·
Registered
Joined
·
8 Posts
Discussion Starter #1
I am converting a 1986 Yamaha SR125 to a street bike/cafe racer and have replaced the old original incandescent bulb turn signals with LEDs. I’ve fitted 2 x minis on the forks with 2 x handlebar end lights on the front and 2 x handlebar end lights on the rear end - modified to fit either side and just above the back springs. I’ve also fitted 4 x 7.5amp (2 front + 2 rear) load resistors to make-up for the low power rating of the LEDs. I’ve also fitted a new speedo bracket and converted the two signal indicator lights (left & right) to a single indicator which (hopefully) will flash when switched either left or right. I’ve also linked this single LED to the new speedo turn indicator LED.
So here’s my problem. Having wired everything (I think) correctly when I switch the turn lights on either left or right then ALL 6 turn lights come on and stay on BUT don’t blink!! Oooooh dear.
Now from what I can tell there seems to be two possible problems:
1. the load resistors I’ve fitted to counteract the 2 x 21W bulbs front & rear is not enough - because I haven’t allowed for the additional 2 x 1.4W bulbs for the original headlamp indicator lights - although in my opinion this additional power load is negligible. However even when 4 x7.5amp resistors are fitted on the front end to counter ONLY the 2 pairs of LEDS fitted on the front - with the original bulb turn lights on the rear - the lights still won’t blink - ouch!!
2. Because on older bikes the turn signal wiring is a little complicated - meaning that when you switch the turn signal (say) left then some small amount of power leaks back. For incandescent bulbs I’m told that because of their inherent resistance they can overcome this power leakage whereas LEDS can’t because of their very low power requirement. To overcome this problem I’m thinking of wiring a 1amp diode on each turn signal +ve wire to prevent this back-leakage.
So my question is which option is more likely to work - if indeed the options are going to overcome the ’non-blinking’ problem. Thanks. Bob
 

·
Registered
Joined
·
706 Posts
Welcome to the forum, Bob. I'd encourage you to head over to the New Member Introductions forum and tell us a little bit about yourself.

If you connected both left and right sides together through that single dashboard indicator, then it makes sense that when you activate one side both sides will light up, because you have bridged them together. Connect the left and right sides to that single indicator using two diodes (one for each side). Anode to the left or right side, cathode to the + side of the indicator.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #3
Thanks RogerC60. Okay will try my Option 2 suggestion wired according to your suggestion. Not sure whether or not one wire each side should be the earth (or ground)? Trial & error I guess. Will revert back once I’ve had a go with the diodes. Thanks Bob
 

·
Registered
Joined
·
706 Posts
It's really pretty simple. One side of each light bulb or LED should go to ground. The other side connects to the blinker control (relay or electronic module). The diodes to isolate left from right do not get connected to ground.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #6
RogerC60: Have wired in the the two 1amp diodes (left & right) into the single LED turn indicator signal on my the new speedo/indicator bracket (to replace the left & right incandescent 1.7W indicator bulbs) and yes now all the left & right LED indicators (3 pairs each side) work independently as they should when switched BUT they still don’t blink - bummer!!
Any suggestions? Is it that the 4 x 7.5amp load resistors I’ve fitted - one front & rear each side - are not making up the equivalent load to what would normally be 2 x 21W each side? What can I try to prove one way or the other whether or not these load resistors are the problem? Or if not what could be the cause as to why the indicators will still not blink? Last resort (I guess) is that I will need to buy a replacement low power relay which doesn’t use a bimetal strip to allow the indicators to blink (flash). thanks, wee bob.
 

·
Registered
Joined
·
706 Posts
Assuming you mean 7.5 ohm resistors, not 7.5 amp. Putting one of these resistors across the wires at each turn signal bulb is the right thing to do. How did you wire them in? They should be wired across the bulb, not in series with it. In other words, the turn signal bulb socket has two wires going to it. You should connect the resistor so that one resistor wire goes to one socket wire, the other resistor wire goes to the other socket wire.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #8
RogerC60: Thanks for your reply. Yes, I did mean 7.5 ohm and believe that each one should be equivalent to a 21W bulb - they have been pre-wired by the supplier so I’m happy that this is correct and I’ve wired them in parallel - 2 on front and 2 on the rear end. I was pretty sure that what I’ve now done with wiring in the 2 separate diodes would do the trick. Obviously not - disappointed!! Any other suggestions for me to try? What about wiring 2 x 7.5 ohm load resistors on one side in parallel as required (but with the two in series with each other - to give 15 ohms) - meaning that I wire 2 x 7.5 ohms on left hand side front and 2 x 7.5 ohms on the same side rear? Is this additional resistance going the right way or do I need to REDUCE the resistance down from 7.5 ohms to say 6.0 ohms? I’m happy to try anything to get a fix but as a last resort should I just go for an LED Flasher relay to replace the original bimetal relay? Thanks. weebob
 

·
Registered
Joined
·
706 Posts
It sounds to me like you have the correct resistors, and they're wired in correctly.

I would add one extra resistor. Do it on either right or left side, but not both. See if that makes a difference on that side. You could also try removing the left or right side wire and diode from that dashboard indicator; maybe that is messing things up. If none of this fixes things, then maybe your best bet is to go with an LED flasher relay. If you do that, don't forget to remove your load resistors.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #10
RogerC60: Thanks for your quick response. I’ve now put 2 x 7.5ohm resistors in series (but in parallel to give 15 ohms) on the left front and rear - but no blinking at all on this left hand side. All 3 pairs of the LEDS light up but do not blink but hey, funnily enough when switched over to the right hand side then the LEDS on this side also lit up - without ANY resistors at all!! At your suggestion I also disconnected the right hand side turn signal wire (with the diode added) to the turn signal LED (on the speedo bracket). With this diode wire disconnected the LED only lit on the left side when switched and no signal light when switched to the right side - as you would expect. But still none of the LED signals blinked - only lit up when switched. To be perfectly honest I’m now at a loss as to what to try next - apart from going down the LED flasher relay route. weebob.
 

·
Registered
Joined
·
144 Posts
If you can get a LED flasher relay I'd go that route. Plug and play with no issues. I didn't have any anyway...
 

·
Registered
Joined
·
8 Posts
Discussion Starter #12
RogerC60 & Meierjn: Thanks to both for your input to resolve my incandescent bulbs to LEDS. After a lot of testing and head scratching I finally resolved the problems. I needed to wire in the two diodes to the Indicator LED on the replacement speedo bracket (Roger you called it the dash). All good & switches and flashes both left & right - yeah! However after a lot of frigging around wiring in load resistors and then taking them out again I still couldn’t get the LEDs to flash. So have now fitted an LED flasher relay. This works - switches nicely left and right and the flash rate is okay too (didn’t buy the more expensive relay with adjustable flash rate). Can do this if I’m not happy with how the LEDs flash once I eventually get the bike on the road. The only issue with the LED flash relay is that when switching either left or right the LED indicator on the dash doesn’t make a noise to tell you that the indicators have been activated. Obviously the old bimetal relay made a noise. It’s not a big deal but I’ve always felt that the ‘clocking noise’ is a reminder that the indicators are on - don’t like annoying other road users with an indicator working for no apparent reason. One other perceived issue is that having fitted the LEDs I’m not sure whether they give off enough brilliant visual light (compared to the old incandescent bulb indicators). Whilst LEDS look good (and are street legal) it’s not great if other road users especially car drivers can’t properly make out that you are going to make a turn. Cheers. wee bob
 

·
Registered
Joined
·
706 Posts
Glad you got it all straightened out. In my experience LED bulbs are as bright or brighter than the old incandescent bulbs.
 

·
Registered
Joined
·
8 Posts
Discussion Starter #14
RogerC60: The replacement LEDs look to shine really good at night but still not sure yet about whether they are bright enough during very sunny daylight. The problem maybe is that they are bright yellow not the normal amber colour. We’ll see!! On a other note I have seen that it’s possible to fit a small buzzer to tell when the turn lights are on - available from RS Components (Radio Shack). Because I’ve already fitted the two diodes for the indicator light then it should be a straight forward wiring job.
Has anybody done this on their bike? Would like to know how effective other riders who have done this think about its effectiveness. Thanks. weebob
 
1 - 14 of 14 Posts
Top