Honda-SOHC
SOHC.co.uk Forums => CB750 => Topic started by: royhall on January 03, 2015, 04:28:57 PM
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Hi. Suddenly got a problem with the indicators on my old unrestored F2 that I use as a daily runaround. Nothing has been touched, but now when I use the indicators I get two flashes then they come on permanently lit. It is the same on both sides. Have changed the flasher relay unit to a known good item, and checked the earths where possible to get to them. Still doing the same. Anybody got any ideas how to proceed, am a bit stumped now. Cheers, and thanks in advance.
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Is that with the engine running? has to have a really good battery to work without
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Its a new battery, that's kept on an optimizer. And yes it is with engine running and stopped. Both sides doing the same thing. Have disconnected the earth cable to rear and indicator goes very dim then bright again when reconnected. Done the same with the front. Suggests the earth to the indicators is okay? Cheers.
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That kind of problem is usually the relay.With the old one connect it back up but run a earth wire to the side of it and if it works there you go.Even I have put the wrong colour wire to the the male prong make sure the grey and black is on the right terminals
Cheers
Bitsa
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That kind of problem is usually the relay.With the old one connect it back up but run a earth wire to the side of it and if it works there you go.Even I have put the wrong colour wire to the the male prong make sure the grey and black is on the right terminals
Cheers
Bitsa
Everytime i get those wires wrong it blows the fuse. My CD250 indicator sometimes comes on without flashing then, starts to flash. Does this about 1 in 8 times.
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I had a 125 if you turned the indicators on they would light up without flashing it turned out to be a dirty switch a good dosing of contact cleaner and all was well.
My 250u had a bulb corrode and seize solid inside the indicator and it caused a similar problem to what yours is doing Trig.
Mick
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I had a 125 if you turned the indicators on they would light up without flashing it turned out to be a dirty switch a good dosing of contact cleaner and all was well.
My 250u had a bulb corrode and seize solid inside the indicator and it caused a similar problem to what yours is doing Trig.
Mick
Will have a look. Switch is well lubed up, all bullets cleaned and changed the relay. Never thought about the bulbs. Has a weird system on those 250u's. If the head light blows, the main beam light on the idiot lights comes on. Though you have not noticed that you are riding in the dark.
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That's strange I don't remember them doing that mind you I never looked at the clocks just thrashed it everywhere
Mick
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Hi Roy, since the fault you describe came on suddenly, and is common to both L & R I guess you can rule out those bulbs / holders / wirings & their associated earths. You need to look at what's common to both L&R sides... ie the pilot lamp, indicator switch, relay, ign switch, battery... and the wirings in between these.
Can I suggest, as a starter for 10 you take a jumper lead & put it directly between...
A & B (if problem cured a fault with the ignition switch (unlikely), or black wire to Relay
C & D (ign ON, Ind switch OFF. If (L) lights flash ok likely a problem in the white wire or ind switch. 'D' can be ANY point easily found in the 'orange' circuit)
C & E (ign ON, Ind switch OFF. If (R) lights flash ok likely a problem in the white wire or ind switch. 'E' can be ANY point easily found in the 'light blue' circuit)
C & F if you can somehow get to the indicator switch feed. Failing this a jumper from C to the switch loom feed in the headlamp shell (?) - sorry, unfamiliar with the F2. If the lights work now (with L or R selection) it suggests a problem in the white wire ... perhaps the twisting headstock?
Note that when doing each of the above checks there is no need to disconnect any bullets / existing connections.
Hope this of use, as a tip if you've fancy OEM type fuses in the holder replace 'em with common house ones (with roughly the same rating) whilst you 'fiddle'
Simon
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Thanks Lobo, that looks like a comprehensive plan will give it a go during the week when work allows. Still using the bike until then. Is it impossible for a fault on one side to effect the opposite side? Cheers.
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Lobo. Just noticed on your sketch that the relay has a ground cable to it. I don't have that on mine (nor is there a position on the relay to connect it to), but there is a green cable nearby that goes nowhere (although its worked like that for years). My other F2 has exactly the same setup. Also the rear light being rubber mounted, has a common ground wire running over the rear mudguard. If that's faulty would it cause that problem? If it is a live feed problem, strange that the indicators light up full bright and flash a few times before going steady. wouldn't they be disrupted in some way if a live feed were bad. Cant wait to get home and have a fiddle now!! Thanks.
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.... that relay ground cable... Yup, I'm on an old K2; though led to believe the set-ups very similar.
The 'old' relays are indeed earthed, and have a lovely mechanical "tick-tick-tick" to 'em. A newer solid state relay can indeed be substituted.... I bought both my old Hondas with the modern two-pin only units , ie the black & white ... with the earth (Green) unused. (have reverted them both to OEM)
I take your point on 'how come they light up if a power problem?' Need someone smarter than me here... but these indicator circuits are 'balanced' for want of a better word.... ie the relay 'flashes' according to the current through it. (BI-metallic strip heating up / cooling down). If the current flowing in the circuit is not within design limits the relay will either flash ultra quickly... or not at all. Reasons for changes in the circuit?.... incorrect wattage bulbs used, a bulb failed, pilot lamp failed, corrosion (may be within a wire), poor connections etc. (pilot lamp unlikely I guess to be your problem)
Because you described both L & R sides failing together I surmised its likely common components to both.
If the rear indicators are lighting up it implies current is flowing freely through them to earth... ie I can't see the rear lamp grounding wire being an issue..
Roy... I've not got years of old Honda experience, and often as not some old hand will put a finger on your problem immediately. Until this time this is the best I can offer...
Cheers,
Simon.
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You asked earlier about a fault one side affecting the other. If your F2 circuit is as above, I don't see how as the indicator switch basically sends the current down one side of the bike... or the other.
BUT... if say your pilot lamp had failed closed circuit (ie shorted)... now all 4 indicators would be trying to work... and may well likely fail full on.
But this isn't quite the scenario you describe...
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Also the F2 has left and right pilot lamps (not a single as per K2) and they both are working the same as the indicators. Ran out of time today so will have a look in the week. If I sort it I shall let you know what it is. Cheers Roy.
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Hi Roy, saw from the Tacho posting that your indicators still playing you up...
.... what a bloody shame; I'm sure we'll all kick ourselves when we eventually learn the problem - it pains me to think you're considering paying a professional!
Horses for courses I know, but this is 70s technology & shouldn't be hard to fathom; eg test each bit of the circuit in isolation until you narrow down on the fault.
As a parting thought are the 2nd bike's indicator values (wattages) / flasher unit all the same spec as the 'poorly' bike? (if not it's no use in substituting the 'good flasher' & expecting it to work.
Does the 'poorly' bike's flasher work fine in the good bike?
It does perhaps smack of a (low) voltage problem (as Bryan suggested).... a job for that new meter!
Cheers,
Simon
PS... in a previous life I used to live in Newton-with-Scales (nr Kirkham); worked down the road at BAe Warton. Lovely spot; the missus (B'pool Vic hospital nurse) & I had some good times there...
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Hi. Have sorted the indicator problems. After an afternoon of playing with it and a few mods to the ground cables to the back indicators, the bike decided to tell me what it was.
When trying the indicators for the millionth time the rear left went out completely. Suspecting a blown bulb, I removed it to find the holder full of crumbly corrosion. On checking, both rears were the same. After a good clean with wire wool and WD40, the indicators work perfectly.
Nearly had me that one, and all the while everything was pointing to a bad ground somewhere. Just unusual that both sides decided to corrode at the same time. I have been using the bike up until Christmas, and been caught out in the rain a few times. Guess some water must have got in. If it goes again I shall just replace the indicators for new.
Thanks all for your help, especially Lobo who went to some trouble over it. Lesson learned on my part, was looking way to deep.
Cheers all.
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Just noticed (shame I didn't earlier). Green1 gave me the answer and I missed it. Jeez, if only I had reread it I could of saved about a day in messing around. The spot prize goes to GREEN1.
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Just noticed (shame I didn't earlier). Green1 gave me the answer and I missed it. Jeez, if only I had reread it I could of saved about a day in messing around. The spot prize goes to GREEN1.
Well it seems a day for indicator problems. Mine was a dry connection on the relay ;)
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I do get things right occasionally.
Give the connections a good dose of ACF50 that's my new favorite product.
Mick
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Got some of that, will give them a blast over.
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I do get things right occasionally.
Give the connections a good dose of ACF50 that's my new favorite product.
Mick
what are you Mick, a salesman ;D
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Na I don't sell nowt ;)
But I did spray that stuff on a few iffy connections on the car and it now works.
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Na I don't sell nowt ;)
But I did spray that stuff on a few iffy connections on the car and it now works.
Mick, do you think it will work on these two >> http://www.ebay.co.uk/itm/Honda-CB350-/151556079250?pt=UK_Motorcycles&hash=item2349723e92
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Did I see the comet that passes close by NO but did see some pink things that flew by
Cheers
Bitsa
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They may be a little to far gone
Buy them for me and i'll squirt em.
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The relay relies on the current flow to discharge the internal capacitor to get it flashing at the correct rate. If you've got a bad earth, that will cause this fault just like an open circuit bulb causes it to not flash.
I've threaded an extra lead from right next to the bulb, through to to the loom itself to overcome any resistance.
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.... fantastic, well done; and glad you didn't pay out cash for some expert to fettle it.
By & large corrosion seems to be the #1 culprit with these electrical problems... forgiven I guess as the bikes all approaching 40!
Simon
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Done the same thing Mike. On the rears the only route to ground for the indicators is through the rear light bracket.
I made up some cables that run from the bulb holders securing screws to the ground post on the back light. Soldered an eye at each end and joined the two together with a piggy back spade connector at the other, then plugged it all in.
The resistance reading on the meter dropped right down. Going to do the fronts as well when I get a chance.
I guess after 40 years of use a bit of corrosion also gets into the indicator mountings etc.
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Good man. Proper job with the ring soldered on. It's the only way to go with 40 year old electrics.