help diagnosing quad battery/alternator issues

[muddy42]

Morning All,
As above I have been having a few issues. The quad is a 2009 Honda TRX 420 CC manual transmission. I've owned it since new, its been serviced regularly, kept under cover and its been pretty reliable. The only major cost has been new tyres and the rear diff and axle which I replaced myself last year.

So last week it wouldn't start with just a clicking noise. It pull starts fine first time. I tested the battery with my multimeter - 11.6v. I charged the battery overnight and it got to 12.6v and it then starts fine.

I left it (and used it a bit) to get rid of any surface charge. Now when the engine is off the battery shows 12.5v. If I push the starter, the voltage dips to about 10.4 but then only return to around 12.4v (or lower if I rev the engine). My understanding is that the alternator should supply about 1v when the quad is running. To me those voltage scores are a bit low but not terrible?

Switching the multimeter and black cable over to DC 10 Amps, I can't find any parasitic draw. No extra lights or winches have been added to the electrical system anyway.

I havn't worked out if the battery is tired, there is an issue with the alternator or charging system or there is something else going on - I know there are various black electrical boxes - voltage regulators or charging regulators etc.

Any advice appreciated?

Thanks,

 

[takbok]

Could be a faulty rectifier. That's the first thing I'd replace.

 

[Kevgun]

I would suspect the Voltage regulator or wiring to it, also small capacity batteries don't like being left to stand, and about 3 years is their limit even if in use.

 

[Happy stalker]

Check the battery is charging, connect multi meter while quad is running voltage should increase showing battery is being charged if not it could be the rectifier or a bad battery

 

[Happy stalker]

The battery in my quad lasted 4 years

 

[seedawood]

I had similarly aggravating problem with my ancient Yamaha, even replaced the battery a couple of times. Finally traced the problem to corroded starter motor brushes. Fitted new (cheap aftermarket from 'Quadbike Wales') started motor and no problem for last couple of years despite only occasional use.

 

[moeggesit]

If it only charge to 12.6v (should be 13.5v ish) on a charger your battery might be faulty. Measure while the engine is running and it should be at 14V +, if not your alternator is faulty. If the alternator is faulty and the battery been run down, both is probably faulty, lead acid can’t handle being drained.

 

[muddy42]

Could be a faulty rectifier. That's the first thing I'd replace.

I would suspect the Voltage regulator or wiring to it, also small capacity batteries don't like being left to stand, and about 3 years is their limit even if in use.

Check the battery is charging, connect multi meter while quad is running voltage should increase showing battery is being charged if not it could be the rectifier or a bad battery

Ive done this a few times, the voltage doesn't increase at all.

The battery in my quad lasted 4 years

this battery is at least 5 years old, probably more like 10 years old

I had similarly aggravating problem with my ancient Yamaha, even replaced the battery a couple of times. Finally traced the problem to corroded starter motor brushes. Fitted new (cheap aftermarket from 'Quadbike Wales') started motor and no problem for last couple of years despite only occasional use.

starter motor sounds strong. I don't think its this yet.

If it only charge to 12.6v (should be 13.5v ish) on a charger your battery might be faulty. Measure while the engine is running and it should be at 14V +, if not your alternator is faulty. If the alternator is faulty and the battery been run down, both is probably faulty, lead acid can’t handle being drained.

Agreed. I think I'll replace the battery first as it is probably overdue. Then I'll see if the quad will charge this.

thanks everyone.

 

[bottletopbill]

Check starter motor or solenoid

 

[finnbear270]

Exact problem I had on a Land Rover (Recently), I was going to reckon on a rebuild starter, and changing the ring gear aswell, Every so often I would turn the ignition key & just get the click, Or the starter sounded like a ring gear problem, Battery was brand new hi capacity, leads all tight, then I wriggled the earth lead where it enters under the two pinching screws, they hardly moved but were making intermittent contact, exchanged for brand new stainless Allen screws torqued down, problems disappeared.

 

[hendrix's rifle]

Could be a faulty rectifier. That's the first thing I'd replace.

Honda and faulty rectifiers? Really it's not like they've had that issue before...

Op, as above, regulator rectifier on Honda are renowned for being poor. You should have three phases and iirc, they should be around 20v AC. One phase is idle, second phase is mid range RPM then high RPM. If one phase is down, you won't get charge. Typically the three wires tend to be yellow on Honda but obviously each one can vary.

Test the battery at idle + through the rev range and then test the output through the reg rec and you should have diagnosed your issue

 

[moeggesit]

Ive done this a few times, the voltage doesn't increase at all.



this battery is at least 5 years old, probably more like 10 years old



starter motor sounds strong. I don't think its this yet.



Agreed. I think I'll replace the battery first as it is probably overdue. Then I'll see if the quad will charge this.

thanks everyone.

It’s worth checking charging voltage before you ruin another battery

 

[Rutland lad]

My motorcycle batteries last about 5 years max, and the one on my Audi (AGM) lasted 3 years. And none of them do small journeys, so recharging after a start should never be an issue.
Like so many things, newer doesn’t mean better.

 

[Will the chippy]

We had the rectifier play up on my dad's quad. It was showing all sorts of faults I really struggled to diagnose it.

 

[takbok]

Agreed. I think I'll replace the battery first as it is probably overdue. Then I'll see if the quad will charge this.

thanks everyone.

That doesn't make sense to replace the battery if you've proved that you're able to charge it successfully off the bike

 

[muddy42]

Could be a faulty rectifier. That's the first thing I'd replace.

I would suspect the Voltage regulator or wiring to it, also small capacity batteries don't like being left to stand, and about 3 years is their limit even if in use.

Honda and faulty rectifiers? Really it's not like they've had that issue before...

Op, as above, regulator rectifier on Honda are renowned for being poor. You should have three phases and iirc, they should be around 20v AC. One phase is idle, second phase is mid range RPM then high RPM. If one phase is down, you won't get charge. Typically the three wires tend to be yellow on Honda but obviously each one can vary.

Test the battery at idle + through the rev range and then test the output through the reg rec and you should have diagnosed your issue

It’s worth checking charging voltage before you ruin another battery

OK, Ive located, removed and tested the cables going to the rectifier regulator.

First I tested the grey plug with the 3 yellow wires (phases from the alternator). I set the multimeter to AC voltage. When I measure from phase to phase 1-2, 1-3 and 2-3 with the engine at idle, they all showed about 15 volts. Shouldn't the engine be producing >18volts before it is regulated?

Secondly I tested the rectifier regulator itself for resistance. I went from each of the two terminals to each phase in turn. All showed some resistance 0.4 Ohmns and nothing in the reverse direction. My understanding is this means the rectifier regulator is OK?

This is a bit out of my comfort zone, so bear with me if my explanation isn't clear.

 

[Mike1979]

If your lead acid battery is 10 years old it will be end of life so suggest this is the issue. The issue is corrosion of the positive grid which results in loss of active material and also of the conductor area. 10 years is good going.

 

[moeggesit]

Sounds ok, I think you’ve gone over and above, would just have checked the charging voltage myself as that proves everything upstream.

 

[hendrix's rifle]

OK, Ive located, removed and tested the cables going to the rectifier regulator.

First I tested the grey plug with the 3 yellow wires (phases from the alternator). I set the multimeter to AC voltage. When I measure from phase to phase 1-2, 1-3 and 2-3 with the engine at idle, they all showed about 15 volts. Shouldn't the engine be producing >18volts before it is regulated?

Secondly I tested the rectifier regulator itself for resistance. I went from each of the two terminals to each phase in turn. All showed some resistance 0.4 Ohmns and nothing in the reverse direction. My understanding is this means the rectifier regulator is OK?

This is a bit out of my comfort zone, so bear with me if my explanation isn't clear.

So the voltage definitely sounds down. What is your rpm at idle? If its slightly low, that could cause it. Retry it and give it a rev, see what it goes to.

I'll try and link a video to show you how to confirm the reg rec is dead because it will save me half hour typing it out and trying to explain the plugs. Sounds like in an ideal world it wants a stator, reg rec and a new battery wouldn't hurt either

 

[hendrix's rifle]

Skip.to 6 minutes or so and try that.