Honda-SOHC
SOHC.co.uk Forums => CB350/400 => Topic started by: billdn on June 28, 2020, 06:33:02 PM
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Having been locked down and then trapping a sciatic nerve for weeks have been unable to ride and battery appeared to have died. So battery recharged but all is not well. Battery after charge read 12.35v, installed and run okay but horn wouldn't work when running but when engine off but ignition on would, for starters. So tried charging volt test as per Haynes manual(all I have) Results dont seem right
1200rpm (tickover) =12.34v
2000rpm = 12.2v
3000rpm =12.2v
4000rpm = 12.22
Lights on
1200rpm = 12.13v
2000rpm =12.6v
3000rpm = 15.5v
4000rpm = 12.3-15.5v (erratic)
With engine running and lights on voltage at same revs as above was consistent between 12.3 - 13.6v but when pressing horn just a faint short beep
I've checked continuity on horn -ok and cleaned up earth where bolted to coil on l/h/s of frame.
The rectifier has continuity too and the voltage regulator - gaps and connections appear in order.
The voltage regulator check mentioned in Haynes , is confusing me (attached) I believe I, need 2 meters -ammeter and volt meter ,as I only have a multimeter , am I reading it correctly?
Battery is a multi batt and my be 3-4 years old . Any ideas where to go next! Or is it just the battery!
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Oops forgot the P.S. when lights are on the voltage fluctuates and the lights dim briefly then the voltage drops then returns to higher level but does it several times. Just to add more confusion to the mix! ???
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Sounds like its charging but battery not accepting it. Modern batteries do not like going flat. Try charging it over a few days and see if it improves also use kickstart for testing not electric
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A multi meter is a voltmeter and an ammeter, just switch scales.
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Cheers both, but Gareth the article reads like I need to connect one to read amps and then switch connections to do volts but at different positions , or am I just brain addled with electrics after todays session!
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Unless you're using a clamp meter, a multimeter can only measure current when connected in series with the battery. In other words, remove the positive lead from the battery and connect the meter leads in between. For this reason, most people stick to measuring voltage.
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BIG THING multimeters DO NOT measure high current so if you put one in the press the starter button its goodbyeee meter
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I'd initially suspect the battery may not be quite right as indicated by Bryan.
12.3v after charging is on the low side, suggesting it's impaired. Reasonably accurate check is to charge it fully with it removed from bike, then record volts after about 15 minutes, then just check battery voltage and record each hour over the day. Healthy, it should stay about 12.6v to 12.9v over a 24 hr period. Heading south from 12.4v usually indicates they've not much practical life left in them.
What can you do with this? Probably only one of the adapting chargers that can pulse charge it up toward 17 volts to try to revive it's status. This attempts to de-sulphate the plates to improve performance, but if you've not got one of the chargers it would be better money spent on a new battery to be honest, especially if it won't hold above 12.3v sitting on it's own disconnected.
https://www.tayna.co.uk/quad-bike-atv-batteries/varta/ytx14-bs/?gclid=EAIaIQobChMI_KzhoYyn6gIVia3tCh24wwAcEAQYAiABEgIo3fD_BwE it may be this size? But these battery and this supplier are very good.
Because your voltage stays steady when running with lights switched on, that suggests the load in that circuit is taking the place of the battery and allowing a smoothed response from your regulator.
One way to check easily, if you've a car, is to remove bike battery and connect bike to car battery with jump leads. Then start and see if voltage is stable from your regulator (effectively using a known good battery to eliminate the bike one)
To do this, connect positive to your bike's red battery feed, then wrap it in something to insulate it from touching anything else, then connect the earth straight to anything substantial on the bike's engne/ frame. Afterwards, remove earth first.
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Thought I'd take the plunge and buy new battery, the old one must be over 4 years old , and if was throwing a curved ball into the equation , technically by replacing it with a known new one should prevent any tail chasing - alas would appear was not battery. Did same voltage test as before and had similar results although voltage did jump up to that specified now and again and the horn worked.....then it didn't and the voltage input remained around 12.3-12.5v! So began testing rectifier with multimeter and cable broke off probe and which point when to pub, oh couldn't but opened a can instead.!!!
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Check the resistance of the yellow wires from the alternator. Yellow to yellow, yellow to other yellow, other yellow to the other yellow.
They should all read roughly the same.
Also check each yellow to earth , should test infinite.
If you've got one or two phases missing, it would account for bad changing.
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Start bike,
let it idle.
Pull the minus cable from the battery while the bike is running.
If the bike stalls, it is either your rectifier or your alternator.
If the bike keeps running it is your battery.
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Check cleanliness and tightness of all connectors especially engine to electric plate block.
I have had one regulator where the moving points would occasionaly "stick" in the middle open position and that was on my 500 in 70's
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Check the regulator points and clean up faces with some fine wet and dry.
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Not ignoring your advice guys, just waiting for replacement multi meter to arrive.!
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So new multi meter in hand of to the workshop! And the scores on the doors read thus:-
Rectifier - appears ok and is giving same values as a new one I'm using another project 400/4 -check!
Field coil - should be giving between 4.6- 5.0 ohms and is 4.9 ohms and is also showing no continuity between white and green wires as required - check!
Stator coil - should read 0.61-0.69 ohms on yellow wires (according to one manual either Clymer or Haynes, forget which) and is giving between 0.13-0.15 although all yellow wires give same reading more or less when tested between them. From connector block which has 3 yellow wires, 1 white, 1 green,1 red/blue and 1 red/green wire only the red/blue and red/green wires are showing continuity - the question is have I found the fault and would this stop the horn working?
only problem now is trying to remove alternator cover screws - 3 out and 1 will not shift , mindful of not breaking lug off of cover too! Sprayed with penetrating oil and wait and see.
As a footnote bought a simple clamp type ammeter and when starting bike dial registers big surge to start then returns to zero.
Any ideas, anyone?
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The large current reading is, I guess, the drain on the battery from the starter motor. There should be a reading as it's charging, but yours isn't.
You could check the ac volts on the yellows and report back.
Well done on buying a clamp meter, they're more useful.
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OK there should be continuity between the white and green wires in the multi block to engine when disconnected but NO continuity to engine case. Numbers between yellows are fairly irrelevant unless you spent £100's on the meter as cheap meters are inaccurate at low resistance readings , if all 3 pairs are same its ok.
Connect the block connector back up and with lights and kill switch turned off put neg of metter to neg of battery them pos of meter to pos of batt and note reading then move pos of meter to white wire going to engine, note reading it should be same as battery voltage.
Report back your readings for further instructions
Dont want to be rude but played this game on the US board and people have a nasty habit of wandering off on a tangent and not reporting what was asked for.
Long distance electrical diagnosis is a swine
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Might be a stupid question but are you sure it is a dc clamp meter as very few of the cheaper end clamp meters are. The ads for them are very misleading. Saying they are ac dc when in reality that only applies to voltage readings.
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Thanks for replies all, please forgive stupid questions, you're dealing with an electrical ignoramus here!
Mike - you mention checking ac volts across yellows -how would I do that?
Bryan - would this be with ignition off or on and testing white wire when block reconnected just push probe into block where white is? Also kill switch in kill position or not engaged ?
Moorey - see attached pics of meter -don't know if it's right type or not!
Once again thanks for help and patience!
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I.T. idiot too forgot to add pics of meter! :-\
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Ignition on kill off mate, does meter say dc amperes accross the top of dial?
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Select an 200v ac range. One probe on the chassis/engine/batt neg, the other probe on each yellow in turn.
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No the ac voltage is between each of the 3 pairs of yellow leads
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Bryan - yes says dc amperes on dial , pic is sideways but when clicked on comes right way up, dont know how to stop that happening
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May have no bearing on matter but "suspect" battery is holding charge perfectly, so now have 2 !
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Bryan - sorry for delay in carrying out test you mentioned but done today. At start with nothing on battery read 12.6v, ignition on read 12.2v and with probe on white wire read 11.06v so not the same as battery. Looking at wiring diagram it would appear this is connected to voltage regulator.
Mike- suggested testing 3 yellow wires with meter set at 200vAC - they read nothing either with ignition off or on.
She who must be obeyed has had her jobs done for now so hope i can be bit quicker for next stage!
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Did you check the ac voltage yellow to yellow as well? If you've got no voltage on the yellows then you need to check the exciter coil. It should have 12v across it.
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The three yellows are the output of the alternator. You do have the engine running don’t you?
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You have a bad connection somewhere between battery +ve and reg output.
Test for battery voltage at black wire at regulator if that is lower that battery go to black in headlamp then black at ignition switch then red at ignition switch.
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Reason for testing this way is if you do not have full battery voltage into the field coil (whie wire) you will not get the full output of the stator, you will get an output but not full output.
And your clip on ammeter is fine but they are not that accurate, should show you if its charging tho'
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The three yellows are the output of the alternator. You do have the engine running don’t you?
Oops didn't have engine running but no tried it and still no reading
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Reason for testing this way is if you do not have full battery voltage into the field coil (whie wire) you will not get the full output of the stator, you will get an output but not full output.
And your clip on ammeter is fine but they are not that accurate, should show you if its charging tho'
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Scores on the doors Bryan
Battery 12.2v
To regulator black wire 0.45v
To headlamp black wire 0.73 v
To black on ignition block 0.70v
To red on ignition block 0.49v
Hope that helps ?
Cheers
Bill
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Further to test on 3 yellow alternator wires reads 0 when engine running but goes to 10 .8 between any pair if lights turned on but back to 0 if turned off?
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You need to strip and clean the ignition switch as half a volt lost red to black is excessive.
With yellow wires disconnected but white wire connected you should get 20-50 valts AC accross each three pairs of yellow wires with engine running
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Voltage measurements are usually made with respect to earth. What voltages have you got on the voltage regulator?
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Bryan
Just ease yellow wires out of block I presume to do check on white wire?
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Mike
Sorry not with you on checking voltage regulator , how would I do that?
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Easier to remove whole block and put a couple of jumpers in for white and green.
Testing is more normally done leaving the black test wire on battery -ve and testing for voltage with red test lead.
On regulator test for battery voltage at black then white
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There's 3 wires on the voltage reg, what's the voltage on them?
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Bryan
Made up leads for green and white but when disconnected block wouldn't start -no power I guess, should I start then disconnect block and add leads then?
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Mike/Bryan
Voltage regulator check
Battery 12.2v
Black wire on regulator 11.7v
White wire. " 0v
Green wire. " 0v
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As battery low, put on charged spare and as I had spare ( used) regulator thought I'd swap around to see if any difference, please see below
Regulator 1
Battery volts engine running 12.59v
Black wire on regulator 12 .12v
White wire 0 v
Green wire 0 v
Regulator 2
Battery engine running 12.60v
Black wire 12.2v
White wire 3.4v
Green wire 0v
Now I'm really confused , ignition switch strip next ps still no horn but guess related to switch?
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Regulator 1 has a fault, Regulator 2 needs the contacts cleaning and somewhere between battery +ve and black at reg is a corroded or bad connector, try cleaning ign switch contacts and retest
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Try shorting the white (regulator output) to black (supply). You'll probably find the battery now charges. Don't leave it shorted, this is only a test. You don't want to cook your battery.
If it goes as I've suspected, you need a new regulator.
You can use a combined rectifier/regulator.
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Thanks Bryan,
just out of interest what voltage should I be looking at regulator black, green and white for future reference. Ignition switch removed, please please don't ask me to to do that again , that was a devil getting that out and back. Ignition switch is about 7-8 years old as having been replaced before but looked ok and cleaned up terminals to ignition connector block.
Did you see message yesterday about testing yellow wires and using jumpers for white and green - was i doing something wrong?
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Poking my nose in, after similar problems found this helpful:-
http://manuals.sohc4.net/general/motorcycle_electrics/HondaMES3.pdf
Forget first page.
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Cliff any help appreciated, will read link but can't say I'll understand it ;)
Bryan - I've repeated earlier test you asked and values shown as follows(previous in brackets)
Battery volts engine running 12.47v (12.2v) with negative probe on battery and pos on white wire to block 3.3v, no previous ; pos on black in headlight 12.12v ( 0.73v) ; pos on black ignition 12.16v ( 0.73v); pos on ignition red 0.05v ( 0.49v) so cleaning up ignition switch may have done something?
Cheers
Bill
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You should still have a higher voltagd on the white wire, more or less full battery voltage after startup.
There are two sets of contacts inside the reg box, or rather one moving one that connects up or down depending on battery voltage. It could be that one of those pairs have high resistance and need cleaning, same as engine contact points realy they can oxidise when not in use
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As I said; short black and white together. This bypasses the questionable voltage reg and supplies the full 12V across the exciter coil. All being well, it should now charge, so replace the voltage reg.
If it doesn't charge, then the fault is elsewhere.
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Bryan - removed regulator, gave points within clean with fine wet/ dry ( dry obviously) and a good spray with electrical cleaner and put back on , no change or possibly lower value on white than before, tried Mike's suggestion and charging ok , so possbly u/s regulator.
A combined rectifier/ regulator is cheaper than new regulator from DS any thoughts?
Or try and source second hand unit from Steve and 400/4 bits.
Cheers Bill
P.S. horn now works - loose wire oops!
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What the reg does is, when it detects the battery voltage is low, gives a 12V output to the white wire.
Yours isn't doing that. The test you carried out proved that the reg is faulty. I would get a combined reg/rec from DSS.
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Mike thanks for that👍 wemoto do similar and are local to me so could pick one up to save waiting, are you aware of any problems with this unit, I guess it'll need some support bracket as won't fit directly in place?
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Or post me the reg and i will fix it, the standard regs are very reliable and the only difference between 400 and all the other sohc is the way the contacts point
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Nice one Bryan can you PM me your address? 👍
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Make sure it's a 3 phase one. You mentioned Lexmoto, they only do small bikes front they? The Lexmoto 125 that I'm fettling is only single phase.
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Mike- no Wemoto not Lexmoto, they're a parts supplier and do good quality parts at reasonable prices. I've used them before , worth a look if you've not seen them on t'net - do mail order too!
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Doh, brain fart 🧠💨. I've used Wemoto many times. Go for it.
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Okay! So going for Elextrex RR24 rectifier / regulator - have removed old regulator (off to BryanJ to have a look and thanks for that, may come in handy for other 400 I have) , looks quite straight forward but I'm bit concerned by this part referred to in parts manual as rectifier assembly (ringed in red) should i remove this and 2 red/green wires feeding it also.
Also any tips on mounting it, noted other threads for 550/4 etc but none for 400/4 - guess doesn't need earthing but needs to be kept cool to dissipate heat I guess?
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The new reg/rec. replaces both the regulator and the rectifier. Bin the old regulator but hang onto the the old rectifier, it can be useful for someone if it works ok. If you mount it in the same position as the old rectifier it'll get enough airflow to keep it within temperature parameters.
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Success!👍 new rectifier/regulator fitted and all works fine! Thank you one and all for your patience , knowledge and advice! Even found a secure mounting spot!
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Well done on sorting out the problem. And you've learned a bit of electrickery in the process.