I've read through a few threads and have some data, but am still scratching my head. At idle, I get roughly 10.7 and 12.6 VAC into the regulator/rectifier (yellow and white wires) and a little over 6 VDC out to the battery (red wire). It's the same with the regulator that was on it and with a replacement ebay item (I know, I know, it probably isn't any good - but at least it seems to have the same result). I should be getting over 12 VDC to the battery, right?

Resistance-wise looking into the stator, I have (yellow) 0.4 ohms and (white) 0.5 ohms to ground (corrected for the 0.4 ohms I get when I short the two test leads.

Hopefully I'm missing something silly/simple?

 

Your input voltages to the regulator are fine. The resistances are reasonable. Correcting for the 0.4 ohm reading when the leads are shorted is also perfectly valid.

But you only have 6 volts DC on the output? Did you measure this with the battery hooked up? A battery that has only 6 volts across it (whether it is being charged or not) is flat dead. I'm wondering if your battery is so hosed that it is overloading the charging system and pulling it into current limit - dropping the voltage to 6 volts. What is the exact battery voltage at idle, and the exact battery voltage immediately after the quad is turned off?

What happens if you take out the battery and charge it up on an external charger (on a 2 amp setting maximum)? Does it ever get up to 12 volts? Or does the battery never finish charging on the 2 amp setting?

Maybe your charging system with one or the other regulator will work fine if you have a really, really bad battery and you replace it with a good one.

There's another possible problem too. There are a lot of identical looking, but incompatible 4 pin regulators out there, and a lot of vendors who who also don't have a clue about what they are selling. But before we enter that quagmire let's eliminate the easy stuff first.

Do these tests and report back:

1) Do you have another battery to try?
2) Do you have a charger (2 amps maximum) to see if you can charge the existing battery?
3) What is the existing battery voltage at idle?
4) What is the existing battery voltage immediately afer shutting off the engine?
5) When the engine is running at idle with the headlights off, measure the battery voltage again. While your watching the meter, rev the engine up to medium fast speed. Do you see any change in voltage?
6) Where did you buy the replacement regulator? Can you post the eBay link?

 

Will get to work this morning with the checks. The battery that was in it had about 1 or 2 volts across the terminals (engine off) and my trickle charger indicated it could not charge it (a simple charger, so it just shows a flashing light as if there were no battery hooked up to it). I've been using a jump start box to start the beast and then disconnecting the box (not just turned off, but disconnected). With the engine running on its own, with no battery in place, I get the 6.5 or so VDC across the terminals.

I'll work on the other things you suggested asap. So weird that it behaves the same with both rectifiers, but as much as this thing has been monkeyed with, its possible the one that was on it was an improper replacement too.

 

Here's what I bought:

http://www.ebay.com/itm/390385409514...84.m1439.l2649

 

I don't have a healthy battery handy - they're installed in my road bikes and I'm hoping to not have to wrestle them out just yet.

With the battery box (portable jump starter) connected, I have 12.25 VDC with the battery connected, ignition switch off, engine off.

With the battery box connected and the engine running (lights on etc.), I have 12.11 VDC across the battery terminals.

 

Okie dokie -

With battery connected, engine running lights OFF, 12.25 VDC at idle and at mid throttle.

With battery connected engine running lights ON, drops immediately to 12.11 VDC at idle and mid throttle.

In either case, the voltage does not change with RPM.

 

I just want to make sure your "battery box (portable jump starter)" has a real *battery* inside. If this box is just a ordinary battery charger that steps down and rectifies the mains power then I don't know what to predict. That would make things a lot more complicated... Simple battery charger/boost boxes just step down and rectify the mains voltage. When the mains AC voltage passes through zero (at 120 times per second) so does the output of the charger. That's could possibly mess your measurements up....

How about jumping the quad to your car battery with the car engine stopped (so the car battery charge system is disabled - remember we are trying to measure your *quad* charging system). Then see if the car battery voltage raises at all from idle (headlights off) when going from idle to a medium fast engine speed.

If the car battery voltage is below 13.5 volts DC at idle, and doesn't rise at all with increasing engine RPM then your regulator is bad.

 

Was wondering if the box would mess the measurements up. It's one of those Costco goodies with an air compressor built in that you can take with you (operates cordlessly, only plugged in to charge it up).

I'm still not convinced there isn't something else going on in the box - I like the idea of using the car battery. Will try that after work today.

 

Tried using the car battery (car off) - with the quad running, headlights off, battery connected, I got 12.8 across the battery. Killed the quad and voltage dropped a couple tenths. Revved it up a bit, and the voltage didn't change.

Weird that is seems to be putting out a bit, but doesn't change (I'm revving it with the parking brake applied, so it isn't' picking up a bunch of rpm). I'll get a fresh battery for it and see what happens when it's really moving.

I think I wasted a bunch of time measuring the battery terminal voltages, with no battery in place. So far, I think it is applying a bit of juice to charge the battery?

 

No, I don't think your regulator is working. It should do better than that. It doesn't take much current to make a fully charged battery rise to 12.8 volts. It really doesn't take much current to raise a fully charged battery voltage to 14 volts either. You can measure this if you want. Pop out the fuse, set your meter to measure amperes (or amps, or current - same thing) on the ten amp scale. Usually you have to move the red meter lead over to a special jack as well as set it to the proper scale.

Insert your meter across the fuse terminals. Now all current that flows into or out of the battery (other than the starter motor current which travels on those heavy gauge wires) will flow through your meter and get measured precisely.

Start up the quad and measure the current level at idle. Note the polarity (plus or minus). Rev up the engine. What does the current level read now? Did it change polarity? This last question is *really* important, becasue when the charging system goes from draining the battery to charging the battery the polarity changes...

Or you could just buy a new regulator...

But there are a lot of 4 pin regulators out there that use the same connector, look exactly the same, and are totally incompatible.

Have you read Tyrone81's thread:

http://forums.atvconnection.com/chin...help-lynn.html

This thread is stuck in my craw because nothing makes sense and I'm completely baffled. I just read back through this thread and am wondering something. You got " 10.7 and 12.6 VAC into the regulator/rectifier (yellow and white wires)", and I assumed then that you had 1.9 VAC between the yellow and white wires. Could you measure this again? Please measure between the AC voltage from white wire to ground, and the yellow wire to ground (same as you did before), and then measure the AC voltage between the white and yellow wires. WHat do you measure for all three of those tests?