Electrical issue with my FJ

[fj12_rider]

Hey guys
     First post so if I mess up I apologise .

My fj is having an issue with , I think , the battery . I had it on charge for 6 hrs yesterday , and it held at 13.5v , this morning I checked it and it`s at 12.77v . the bike turns over nicely and the lights all work etc but they indicators make the other lights flash . The bulbs are all correct , headlight 60/55 , indicators 21 , etc , the thing thats making me wonder if its something other than the battery is that it does it at 5000rpm with the battery reading 14.5v , obviously its worse at idle but I would have thought that it would stop doing it at high revs wouldnt it ? Sorry should have said the headlight gets brighter with revving

FJ1200 , 1990 3cv

Cheers guys ,

P.s. I`m a new owner of this bike and I absolutley love it . Of all the bikes I have this is the first one I`m calling a keeper !

[Arnie]

The battery dropping V a bit from just off the charger to sitting overnight is pretty normal.
But the flasher draining enough to be noticeable with more than 3K on the tach is concerning.
I'd start at the battery and remove, clean, and re-attach each connection, switch, and socket.  At the same time, wiggle the wire to see if you can feel broken wires inside the insulation. 
You don't mention if its been stored for a while and inside or out, but corrosion is a normally occurring process especially when electricity is also present.  It'll take time, but getting full voltage (or as full as the skinny wires Yam used will pass) will help keep things bright. (pun intended)

Arnie

[FJmonkey]

Hey guys
     First post so if I mess up I apologise .

My fj is having an issue with , I think , the battery . I had it on charge for 6 hrs yesterday , and it held at 13.5v , this morning I checked it and it`s at 12.77v . the bike turns over nicely and the lights all work etc but they indicators make the other lights flash . The bulbs are all correct , headlight 60/55 , indicators 21 , etc , the thing thats making me wonder if its something other than the battery is that it does it at 5000rpm with the battery reading 14.5v , obviously its worse at idle but I would have thought that it would stop doing it at high revs wouldnt it ? Sorry should have said the headlight gets brighter with revving

FJ1200 , 1990 3cv

Cheers guys ,

P.s. I`m a new owner of this bike and I absolutley love it . Of all the bikes I have this is the first one I`m calling a keeper !

Welcome fj12_rider, what you describe does not sound like a battery issue. A low battery will allow the lights to come on but will be weak or non-existent while cranking. 14.5V at 5K means your alternator is good. Headlamp dimming and getting brighter with revs is normal. At the lower revs the alternator is not producing so the voltage is what the battery is providing. Increase the revs and the alternator kicks in and the electrical system gets the extra voltage. The headlamp is also not powered directly to the battery so there is also some voltage loss through the harness. Some have added a relay to power the lamp direct to the battery and still have it switched properly through the harness. And some like myself have installed HID and have sunlight shooting out front.

Back to the flashing issue. What lights are flashing when the indicators are flashing? Are they dimming and getting brighter with the indicators? Or going On then Off with the indicators? Are the indicators flashing at a normal rate or do they seem to flash too quickly?

[fj12_rider]

Thanks all for the replies .

It hasn`t been stood . I`ve just bought it but it was used daily by the previous owned *albeit only to go 6 miles to work

The lights that are dimming with the indicators are , well , all of them . The head light , stop/tail , dash , everything . The indicators are normal , nice and bright and flash at the correct rate . Another thing I found today while whizzing around with the multimeter is that the output at the side / parking light is only 10.6v which is concerning this is making the parking/side light VERY dim .

[FJmonkey]

Electrical is not my specialty but it seems like something got tied into one of the wires feeding the indicators. Or an accidental short has done the same thing. Not sure if the flasher unit going bad would cause this.

[fj12_rider]

yeah you and me both mate. the lights dont "flash" the just dim ever-so-slightly , but enough to be noticed . It`s like the old 6v system on a yammy rxs100 for instance . It just seems like the system isnt up to the job , of course it is but just using that as an example . I`ll have the plastic off it tomorrow and see what I can find. there has got to be something amiss within the wiring somewhere

[nurse]

Another thing I found today while whizzing around with the multimeter is that the output at the side / parking light is only 10.6v which is concerning this is making the parking/side light VERY dim .

That's because its only a tiny 3.5w bulb in there!  Even mine is/was dim and the electrickery is ok on my bike.  I swapped the bulb for an led equivalent which I wouldn't say is brighter but has a crisper/whiter colour which feels brighter (maybe its just me)!

The parking light will never be that bright!

[Wesley]

Had a similar issue to this on a 4 wheeled encapsulated bike (ok dammit i drive a car once in a while  ) Tuned out that the earth wire from the rear had corroded and the indicators were earthing through the stop/tail light so i suggest beginning you're search on the earth wires to the rear under the seat. Definately NOT the battery at fault the readings you are giving for the battery are perfectly normal.

[fj12_rider]

cheers guys , you are all confirming things for me . I think i`ll start by adding a new earth and go from there . I`m pretty sure as wesley said its an earth problem . I`ll have it to bits again tomorrow and trace all the earths and maybe replace the ones in the lighting system till I find the one thats causing the issue . I hate taking it apart because its pretty much in mint condition cosmetically but needs must .

Thanks for making me feel welcome guys !

Dave

[FJSpringy]

I know its been said a millions times but have you cleaned the earth at the rear of the motor.

[racerman_27410]

I know its been said a millions times but have you cleaned the earth at the rear of the motor.

that same earth cable went crunchy on my FJ..... bad things happen when you lose the ground.



KOokaloo!

[RichBaker]

You have a bad ground, one that is associated with the lights... The ground lead is attached to each socket via a crimp, and they will break, eventually. I had the one to the R frt socket break, that one used the other filament to get a ground and the lights would flash faster than the left.

[fj12_rider]

well i`ve had the main earth strap off today and that was green on the end . On closer inspection it was black throughout 75% of the whole strap . so thats going to be replaced , Pretty sure its not the cause of this but still its not helping . Once i get a replacement I`ll carry one the diagnoses . Off the road for a few days as its a pain in the butt to get too so leaving it stripped for now. Needs must and all that . I`ve got nothing heavy enough to make one up really , i`ve got some heavy twin and earth but nothing as heavy as the as the original one .

[fj12_rider]

 I`ve just found that there are 2 points that have been cut . one is to the rear of the seat and the other is attached to the rear brake master cylinder . Also the rear indicators have been changed for smaller ones . They have 21w bulbs in so I dont think thats going to make a difference . Does anyone know where these 2 points are supposed to go ? Looking at the harness they dont seem to come from there as there is nothing hanging . This DID have heated grips but they got pulled out so one of them could be from those . just the round crimp connectors that bolt to the frame are left.

Thanks for your help guys . I`m kinda struggling with this a bit . I checked all the wiring upfront and rear for loose connections to no avail , nothing looks loose or out of place .

[fj12_rider]

Ok i`ve sorted it out . I hunted and hunted for the problem for about 20 hours in total and couldnt find what was going on . I fitted a new earth strap , ran a new earth to each appliance one at a time and nadda .

So to combat the issue I bought some 20a relays and ran new lines to each of the high and low beam and the stop and Tail light and used the original loom to trigger the relays , No more flashing , It hasnt "fixed " the problem persay , but it works !