Indicator voltage up and down?

dray

New Member
Hey folks this is a repost from my build thread but i thought it might be useful to repost it here. I have an indicator problem. Rear indicators working fine. Front indicators not so much. So I have an electric riddle which I could use some help with.
Rear indicator voltage output is a healthy 12.54v
Front voltage Right side is 10.30v steady.
Front voltage left side is on a continuous variable voltage from 4.5v up to 8v and back down again...
It seems the indicators for the front that I want to use won't accept anything but 12v.
I can attach cheap indicators to the front which work though rather weakly.
I though maybe I could try removing and bridging some resistors on the indicators I want, though I don't know which resistors to remove.
How to fix please.
 

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You need to find where your voltage drop is. You should have full battery voltage -.1v or so at the front of the bike.
Disconnect and clean all connections between the battery and the indicators, then check and clean all grounds and then report back.
 
SONIC. said:
You need to find where your voltage drop is. You should have full battery voltage -.1v or so at the front of the bike.
Disconnect and clean all connections between the battery and the indicators, then check and clean all grounds and then report back.

+1

You probably have a connection somewhere that is incomplete or corroded and so your parallel circuits are acting like a voltage divider.

Removing those resistors will probably result in you cooking the LEDs.
 
thanks heaps for the feedback fellas, it means a lot to me, I'd be lost with out it!
So I've made some progress but no resolution yet. Yes definitely there's some issues with earthing but have not yet pin-pointed it.
Attached is the original wiring diagram for the KZ250c(hard to find!), originally in German but i made a few quick translations.
For the purposes of this thread, modifications are -
Replacement of odometer and tell signals with incorporated unit.
Replacement of indicators with LED indicators.
I started testing voltage beginning from the flasher relay then left side switch block. So far so good, all above 12v no drops. followed grey wire (+) which then split to front and back indicators. Here voltage started to vary so I cut to isolate the front end and did more testing.
Long story short, after degreasing, scrubbing, replacing, splicing, re-soldering and testing various connectors as well as renewing some common earth and ground points I have concluded that the Odometer is causing issues or at least is part of the problem. It's a cheap Shanghai special so I'm kind of not surprised.
Basically when i bypass the odometer and connect the indicator to common earth it works, bring the Odometer into series and the indicator tell signal lights up but the actually indicator does not want to flash.
Suggestions if you please.
Thanks
 

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I had a similar issue when switching to LED’s where if all the turn signal bulbs were not LED’s it threw the whole system off. What I ended up doing was switching the wiring of the light in the odometer, so it flashed opposite of what it’s supposed to do, and also switched the turn signal flasher to an electronic unit.


Sent from my iPhone using Tapatalk
 
Ok so I found and resolved the issue!
After discussions with some local electric moto wizards (picture if you will, long beards waving around soldering irons) I was given a few options involving transistors or alternatively (the path I took) instead of running everything in series, I could run an earth from the indicator to the common earth in parallel with the existing circuit!
i.e pos + > Indicator > odometer > common earth. vs pos+ > indicator > common earth + odometer > common earth.
Once I wired up the second wires from both front indicators and connected them to the shared earth - boom - Merry Christmas.
So it would appear that these cheap odometers have high value ohm resistors in them to protect the 5mm LEDs and downgrade the voltage, problem with this is the output voltage - is not high enough for the indicators to fire up.
moral of the story - buy quality parts or waste time fixing cheap parts.
Cheers all!
 
Like I said check your grounds :D
When in doubt ground direct to the frame and check again, that will usually show you if you have a ground issue somewhere along the line.

Glad you got it figured out.
 
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