80's Honda 125 Indicators not Flashing

[caferacer]

Hi all,

Having done a fairly thorough job of going through the electrics on my early 80's Honda CB 125 (12V) I've hit a problem with the indicators

Here's where I'm up to:
Replaced Battery
Cleaned up Fuse & Holder
Replaced Regulator Rectifier
Replaced Headlight Ballast Resistor
Replaced Charging System Ballast Resistor
Replaced all Bulbs
Added new Earth wires to ensure good connections

The lights now seem to be working without blowing which was my original problem.

However, when I switch the indicators ON they stay constant rather than flashing. If I rev the bike to the red line they do blink but not consistently.

So this sounds to me like a problem with voltage. I'm getting a reading of about 10.5V across the battery whilst the bike is off and it remains at a constant 10.5V whilst the bike is running and revved up.

The headlight seems nice and bright and the indicators aren't dim when they come on.

Also, when the bike is not running none of my lights work (with ignition key in and turned). I'm guessing this also relates to lower power in the bike although can't see how if the battery voltage is remaining constant?

Any ideas on things I can check to help track down the problem?

[caferacer]

Just a thought - the new battery was fitted last year and the bike hasn't been on the road since. Is there a chance a good long ride before my MOT might charge it up and fix the problem?

I don't own a charger for the battery.

[stirlinggaz]

Hi,
Not having a charger doesnt help,well worth investing in a decent one.
the 1 I have recovers batteries as low as 4v.
you have a multi-meter though,yes?
Easy enough to test battery & charging circuit.
btw, is the little idiot light working? the 1 that flashes in sync with the indicators.
If the wee bulb in the dash goes, sometimes this results in all 4 indies illuminating constantly,
Cheers,
GAZ


ps : you do know that a pre 86 bike doesn't need indicators?

[caferacer]

[caferacer]

Perfect - switched my bulbs around in my dials and the indicators are blinking much better now.

Still a little unsure of itself on the right hand indicator - will check the earth on that again. Maybe just the battery still waking up??? Seems to be happier at higher revs...

Noticed that the new (old) dials I have fitted must have been off a 6v bike but the 6v bulbs seem to be holding out apart from that turn signal one... even so I'd better replace them with 12v ones...

[stirlinggaz]

hi,
hth
found that one out a while back after going through a whole loom with multi-meter, checked all connectors, replaced the relay umpteen times....this took place over a couple of days until i decided to replace all the idiot lights with fancy blue ones.
the indicator tell tale had blown, once replaced normal indicating resumed.
on my 1986 gamma + some other bikes i dont have indys + rely on hand signals. can be fun.
whats not fun is getting pulled by plod (even traffic plod) who seem convinced i MUST have indicators, clowns.
anyway, i digress....if i were you i'd replace all the tell-tales with 12v ones, usually 3w or similar,
cheers,
GAZ

[Tedwood]

[caferacer]

[Tedwood]

[caferacer]

Thanks Tedwood,

Super helpful post!!!

Light is fading now here so Ill have to test tomorrow.

I will definitely check out those voltages on the alternator exciter coil for you. Are you sure you had your alternator on the right setting for reading your resistance here. That sounds very low... Are you sure it's not 0.3KOhms? Sorry - don't want to sound patronising (mainly as I have no clue myself).

I'll update once I've got the reading.

[caferacer]

Results

Battery was disconnected when I started to test so I thought I'd include my initial results too.

[caferacer]

In terms of the charging ampage:

I believe I'm getting a reading of 13 x 50 micro amps

So that's 650 micro amps which is 0.00065 amps.

Most trickle chargers for motorcycle batteries charge at about 2 amps so I'm guessing my charging rate is unsustainable if my reading is right.

Of course it could be any flipping one of these 12 dial readings on my multimeter.

Also I could only get a reading on the negative side of the battery which doesn't sound right to me either.

I've just checked the fuses in my multimeter and all are fine.

[Tedwood]

Many many thanks for the readings from your bike, which I think confirms that they are virtually the same as mine.

Personally, I'm convinced that there is a wiring problem with your bike.

Has the wiring been modified? Does it have the correct Ignition and Lighting Switches fitted?

If you have a wiring diagram, I would suggest that you trace and check for continuity of all the wires and ensure that the connections are good and the correct colours are connected together.

As most of the connections are in the headlamp shell I would start there first and just see if all the connections are correct in there. Especially the Ignition Switch and Lighting Switch connections to the loom.

[Robby]

Have you charged the battery yet? If it's a conventional lead-acid battery with a transparent casing, having you checked/topped up the fluid?

If not, do so before you start testing anything else. Battery off the bike, topped up with distilled water, then left on a smart charger overnight.