help diagnosing quad battery/alternator issues

Get the stator changed as I've already mentioned. When I used to spanner on bikes (mass scale) if a stator put out LESS than 18v it would be replaced because it had gone gone bad.

If its reading 15 you're already ****ing in the wind.
When its running and you hold revs say 4k, what voltage are you seeing in the battery?
 
Thanks. I'm not sure my friend. Post 44 is the correct wiring diagram for the pre-2014 hondaTRX420. This shows that the 5 pin plug has 2 aspects - three phase stator and a "CKP sensor.' Google says this updates the brain about the position of the crankshaft for ignition timing etc. I was lying under the quad when I tested these two contacts, so I couldn't vary the rev. As far as I recall it was battery voltage at idle, so i'm baffled as to how the voltage can increase from this. I would need to take the plastics off and enlist my beautiful assistant to help with this.

Various googling says these stators can produce up to 90v and its purely driven by engine rev, which the regulator rectifier sorts out. I guess it this will result in heat and thats why this black box has fins and is on the outside of the quad. Plus it probably explain why these devices commonly get fried and go wrong.

The quad has sat unused without any trickle charge for a few days and is showing 13.2v. I think that's fairly decent. I'm going to re check for parasitic leakage (I'm not 100% sure I read the decimal places and greek letters ųA, mA etc. correctly!). Then I'll install a voltage gauge and just monitor the battery health for a while.
Ok, so if the rec/reg is controlling the excitor current we need to see if it bizarrely is dropping with higher engine revs.
Did you say it's a new unit?
They have cooling fins because the rectifying diode gets hot not because it's converting high AC voltage into heat as a means of controlling output.


I doubt I can assist any more sorry.
 
Ok, so if the rec/reg is controlling the excitor current we need to see if it bizarrely is dropping with higher engine revs.
Did you say it's a new unit?
They have cooling fins because the rectifying diode gets hot not because it's converting high AC voltage into heat as a means of controlling output.


I doubt I can assist any more sorry.

Aye new unit - rectifier/regulator.
I have studied the stator AC at varying rev. It does vary - 15v at idle up to about 33v at mid rev (not checked with the tach yet). Both those numbers are low. I think the stator is working but its just weak.
Agree, ive spent enough time on this.
 
Get the stator changed as I've already mentioned. When I used to spanner on bikes (mass scale) if a stator put out LESS than 18v it would be replaced because it had gone gone bad.

If its reading 15 you're already ****ing in the wind.
When its running and you hold revs say 4k, what voltage are you seeing in the battery?

13.7v or so.

Look let's just leave this thread here, its getting unweildy. Thanks for the help everyone, I've learned a lot. I've replaced the battery and regulator rectifier.

As described I am just going to monitor the situation for a bit with my voltage gauge. If the battery gets close to being dangerously discharged, I'll trickle charge and then replace the stator. But its a 16 year old quad and not worth chucking new parts at or spending too much time and money on.
 
13.7v or so.

Look let's just leave this thread here, its getting unweildy. Thanks for the help everyone, I've learned a lot. I've replaced the battery and regulator rectifier.

As described I am just going to monitor the situation for a bit with my voltage gauge. If the battery gets close to being dangerously discharged, I'll trickle charge and then replace the stator. But its a 16 year old quad and not worth chucking new parts at or spending too much time and money on.
Actually I just used the quad a bit. When running around the volt meter shows 14.3 - 14.6v.
 
Apologies… bit late to the party but this might be of use for anyone looking to replace a quad regulator/ rectifier in the future

I recommissioned my Honda 750 a few years ago and the 3 yellow wires from the stator going into the heavy duty connector before the reg/rectifier were ‘cooked!’ to put it mildly

IMG_2041.webp

Then someone recommended Electrex for a replacement
Electrex World Limited
Using one of their HD connector blocks (crimp connectors supplied) and Reg/Recs I could connect it straight to the battery without sending anything back round the wiring loom. The only adjustment I had to make was to re-locate one of the mounting holes through the mudguard and revert to a standard battery as they can’t be used with L-Ions 🫤

Cheers

Fizz
😎

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IMG_2581.webp

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It looks like the fecking startor motor is going now. Intermittently, I just get a click from the solanoid. I will clean the connections and check the voltage going into the starter motor, before ordering parts.
 
Yep. Battery voltage is first thing to check.

Put battery back on trickle charge and see if you get same symptoms.
 
Yep. Battery voltage is first thing to check.

Put battery back on trickle charge and see if you get same symptoms.
Thanks. Trickle charge makes no improvement - I still get intermittent solanoid clicks (but not every time). Battery is new and still load testing as healthy.

I'll clean the connection and check the voltage at the starter motor, but I fear its an issue with the starter motor itself.
 
Thanks. Trickle charge makes no improvement - I still get intermittent solanoid clicks (but not every time). Battery is new and still load testing as healthy.

I'll clean the connection and check the voltage at the starter motor, but I fear its an issue with the starter motor itself.
Or possibly solenoid itself?
 
Or possibly solenoid itself?
Frustratingly everything is working fine now, the quad starts every time. All the connections look clean and the starter is getting voltage. Ive had this kind of intermittent click with other vehicles and I expect the issue will reappear. I've stashed a bar on the quad to hit the starter motor with, if it resurfaces. Then I will know where the issue is, for sure. It has a starter cord, so Im unlikely to get stranded.
 
So little update to this. The quad has had a new battery and regulator/rectifier and has been working fine using a trickle charger every night. I tried leaving the trickle charger off and within a week of low use the battery was depleted.

As I suspected in post 23 I think the stator isn't performing as it should. Plus there are some other mysetry electrical issues that I can't find - parasitic draw and starter motor. I don't feel capable of opening up the engine to replace a stator. It would be £500 - £600 in the ATV garage.

I think I'll just keep trickle charging it and start thinking about buying a newer quad. Plus I need more cc for towing.
 
So little update to this. The quad has had a new battery and regulator/rectifier and has been working fine using a trickle charger every night. I tried leaving the trickle charger off and within a week of low use the battery was depleted.

As I suspected in post 23 I think the stator isn't performing as it should. Plus there are some other mysetry electrical issues that I can't find - parasitic draw and starter motor. I don't feel capable of opening up the engine to replace a stator. It would be £500 - £600 in the ATV garage.

I think I'll just keep trickle charging it and start thinking about buying a newer quad. Plus I need more cc for towing.
If it’s like on a grizzly, it’s drain the oil and water, then remove a cover nothing really intrusive to the engine.
 
If it’s like on a grizzly, it’s drain the oil and water, then remove a cover nothing really intrusive to the engine.
I'm tempted but Ive never done a repair on this scale. Based on past experience on working on other engines, this would take me much longer than Id ever imagined. I also have this niggling fear that there may be something else wrong.

The nocco trickle chargers are pretty good. Ive rigged it up so the cable comes down from the ceiling and there is a permanent waterproof connection to the battery so you dont need to remove the seat etc. Its very easy to plug in after use.
 
I'm tempted but Ive never done a repair on this scale. Based on past experience on working on other engines, this would take me much longer than Id ever imagined. I also have this niggling fear that there may be something else wrong.

The nocco trickle chargers are pretty good. Ive rigged it up so the cable comes down from the ceiling and there is a permanent waterproof connection to the battery so you dont need to remove the seat etc. Its very easy to plug in after use.
I agree wholeheartedly with the sentiment of your decision making.
Your quad is still perfectly usable as is.
You might spend a considerable amount of time and money and not improve matters by following up on stator replacement.
@wytonpjs suggestion of fitting a battery isolator switch would be a relatively simple improvement that I would undertake if I was in your situation.
 
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