Honda CBR125: Strange Indicator Problems!

[laurence231]

Hello!

A rather strange problem with my CBR125, and there doesn't seem to be much on the internet about this...

The Indicators work correctly in only a few cases -
1 - When the ignition is on
2 - When the bike is started and idling
3 - When the bike is at higher rpm AND either front or back brake is slightly compressed (and lights subsequently turned on)

The indicators FAIL when the RPM is above a certain value

From what I've managed to gather from other threads -
-An issue with grounding (although I'm not so sure how to diagnose/deal with this?)
-An issue with the indicator relay (tempted to just buy a new relay anyway as they are cheap enough)

Something else entirely? Anyone had to deal with this before?
Any thoughts appreciated

Edit: What I have done so far - Cleaned contacts between all switches, cleaned switch between both relays and connectors, charged up battery fully, checked all bulb contacts, replaced the left hand side indicator switch/lightbulb/horn assembly with a new one, nothing so far.

[Grubscrew]

Some indicator relays work on a bi metallic strip, but the more recent ones are more modern internals, ie a mini coil and contact breaker like device.
It would appear it works on a lower voltage, say 12v, but on revving you should have 14.8 v or there about.
Try the cheapest option, ie new flasher unit,then go on from there.
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FJR1300/CBR1000F

[Teflon-Mike]

The grounding is simply using the frame as the return half of a circuit... get a bit of wire, attach one end to the negative terminal of the battery, to get a good possitive ground, and the other, to the negative, earth side of your device, eg indie... if it works better/properly, there's your problem, the earth side of the circuit isn't earthing properly... look harder to find where circuit either not being made of going high-resistance, trying to earth through say another lamp, or make up seperate earth path with a permenant bit of wire back from the indy or device, all the way to the negative terminal on the battery.

06 CBR125.. one has to ask, at that vintage, has it even still got its Original Indies? I would expect on a learner bike of that age and posiness, that its been dropped more than once or twice, and good odds that original indies gone west a long time ago, replaced with after-market e-bay specials, likely without the EOM plastics or mounts or bracketry that would likely form part of the earth path.

The change in symptom as the engine revved, suggests gross voltage change with rpm, which denotes a rectifier/regulator issue, possibly a duff battery not damping voltage spikes too well... and that needs to be sorted too.

So it sounds like you have a bag of faults to tackle...

As to the 'relay'.. Ahrg!! its not a fugging 'relay' its a chiffing flasher unit, or flip-flop gate!!! Just looks like a relay does!

A relay is an electric switch; one circuit, usually lower amperage turning on or off another circuit, usually higher amperage! It means that you dont need such a big switch or thick wires for something like a head-lamp...

A Flasher unit is a flasher unit... and conventionally is load sensitive; works like a relay, which is why it looks like one... but the supply volts go in, and trip a selenoid to turn itself 'on' and make indy flash... but soon as it has and the solenoid contact moved, it turns 'off' the supply, so it turns itself off again... and in that state... it does it again, and again and again, flip-flopping, turning the supply voltage on and off on the out-put. This is an electro-mechanical flasher, and the timing of the flashes is governed by a) the weight opf spring returning the contactor plate against the solenoid, and the wattage of the indy bulbs coupled to the other end of the circuit, the lower the total wattage, the faster the flasher will flash.

Other, more modern type, is the solid-state or 'electronic' flasher. This uses high current transistors as the switch to turn on and off the supply, timed by a chrystal, like a digital watch. With no moving parts, these are silent, they also dont draw much current themselves to work themselves, and they always give a fixed flash rate from the quartz chrystal.... and these days are pretty cheap and quite reliable. I rather like them.

Bi-Metyalic strip flashers mentioned, are a little perverse. They work by having a bi-metalic strip that gets hot when electric passes through it, and move between contacts, rather than have an electro-magnet move it. Rather electrically inefficient, as well as dificult to time, as they rely on the cooling rate of the bi-metalic strip, when its switched off... I dont know of anything, bike or car, that has, in modern times used one of these, since semaphore trafficators!

However... if you had a faulty flasher unit, the flasher would tend to either not flash or always flash slow or fast... as said, you have a bag of faults, starting with the volts varying with revs, and here and now is, that until that, and possible earthing issues are bottomed, nothing actually says you have a fault with the flasher... but... if it were to be changed... then I would personally fit an electronic one... mainly cos they are like £3 cheap from china, they are reliable, and you can hang LED indies off the end, or low wattage bulbs, even mix and match bulbs between back and front, and the still flash at MOT happy rate... but your call on that... first you need to find and fix the other faults and actually prove that the flasher you have is indeed faulty in some way.
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My Webby'Tef's-tQ, loads of stuff about my bikes, my Land-Rovers, and the stuff I do with them!
Current Bikes:'Honda VF1000F' ;'CB750F2N' ;'CB125TD ( 6 3 of em!)'; 'Montesa Cota 248'. Learner FAQ's:= 'U want to Ride a Motorbike! Where Do U start?'

[Meatybeaty]