Rectifier Regulator Diagnosis Question

[maro6613]

Hey all,

I've been having problems burning bulbs out, so I took a look at my regulator (and quite a few old posts) to see what was up.

First: it appears I have an aftermarket rec/reg, one of these (Link!) from AF1. It also appears that the PO got rid of all connectors, simply splicing all wires together directly. Finally, it appears the wiring mod had not been done - no extra wires to the main fusebox, no extra 'yellow' wires, etc.

Now, with the bike off my battery measures 12.99V. So far, so good.

I turned the bike on and let it idle, the voltage at the battery was initially ~13.5V, and began slowly climbing, with intermittent spikes in the 17V (!!!) range. After a few of these spikes, I turned the bike off, for fear of frying things that are much more expensive than bulbs. By that time, the voltage (excluding the spikes) had risen to ~14.4, and was continuing to rise. I did not run it at 4K rpm, for fear of angering the electric gods.

I know there are two possible culprits, based on prior forum posts: either (a) the rec/reg has gone belly up, or (b) there is either a bad connection somewhere, likely a ground.

I have a decent knowledge of electrics and the like, but am by no means an expert in bike charging systems -> which of the above two options is more likely the failure point with my above symptoms? I'd like to know where to focus my attention, hopefully in short order because I have a long ride planned for next weekend, and would need to order a rec/reg in short order if it has down the tubes.

Thanks all!

[deefred]

It´s probably the R/R, but try connect a temporary ground directly to the battery negative from the R/R and see if it make a difference.

[Motech]

That is a faulty voltage regulator, period. Nothing else on this type system can cause that high charging voltage.

Get one of John B's RR units (BikePaintr) and don't bother with extra wire mods.

[maro6613]

Perfect, thanks all. Is this part on AF1, or do I have to get it directly through John B? Also, what is the difference between this unit and the two units from Rick's Motorsport on AF1?

One last question - I'd like to have connectors put back on, but the PO removed them and soldered the wires directly. I know aftermarket RR unit comes with the OEM style connectors (one brown, two white) - anyone know where I can get the mating connectors that originally came on the bike harness? If there isn't a convenient source, I'll probably either just (a) cut n' solder or (b) go with Metri-Pack style connectors (Link!).

[deefred]

I would not completely rule out a bad ground.
Attached is from Aprilia manual

I would also go for a MOSFET R/R as they run much cooler and heat is what is killing R/R in the first place.

[Stanleybobly]

I would not completely rule out a bad ground.
Attached is from Aprilia manual

I would also go for a MOSFET R/R as they run much cooler and heat is what is killing R/R in the first place.

[bikpaintr]

I'd agree about checking for a bad ground. Every time I've seen high charge rates like that it is ground related.

[bikpaintr]

Nothing against the Moffet but the numbers shown in the second video are no better then what you get with the standard aftermarket rectifier.

[Motech]

For a bad ground to show overcharge, I believe it would technically be showing the volt DROP equally on the positive side, IE: 2 volt drop from ground side = 2 volt increase on positive side. When you subtract the drop from the increase, you'll typically find it's not a true overcharge, but compensatory increase in measured voltage.

To know for sure, you'd measure volt drop between battery negative and engine with engine running, high beams on. If OK (under 1/2 volt), then measure between regulator ground and battery ground. If OK, it's a bad regulator.

If you find high volt drop on the ground side--say, 3 volts or so--you might see equally false/misleading charging volts at battery positive, say, 17 volts or so.

Resistance in ground circuits can cause all sorts of weird, high-voltage problems way beyond just charging systems. Learning and using very simple volt-drop testing methods makes real quick and easy work of tracking them down, and takes all the guesswork out of some of the most irksome electrical issues we all encounter.

[Motech]

Perfect, thanks all. Is this part on AF1, or do I have to get it directly through John B? Also, what is the difference between this unit and the two units from Rick's Motorsport on AF1?

One last question - I'd like to have connectors put back on, but the PO removed them and soldered the wires directly. I know aftermarket RR unit comes with the OEM style connectors (one brown, two white) - anyone know where I can get the mating connectors that originally came on the bike harness? If there isn't a convenient source, I'll probably either just (a) cut n' solder or (b) go with Metri-Pack style connectors (Link!).

Talk to John/bikpaintr, I believe he can probably accommodate your connector needs too. FWIW, I and many other Aprilia riders I know are running his hardware with very good success and no hacked-up mods.

[bikpaintr]

I have the white connector & terminals but the harness side of the brown connector is only available by buying the harness section AFAIK.

Re the overcharging. I've had two or three customers complain that the rectifier I sold them had started over charging since I started selling them. Each time the returned rectifier tested good & each time the customer eventually found the cause to be a poor ground connection.

[maro6613]

Hey all,

I checked the ground wires on each side of the engine, they check out fine - I took them off and sprayed with contact cleaner just in case. I jostled them all around in every direction I could to try to find intermittent grounds - I found no more than 0.1ohm between the contacts/engine case and battery ground.

I then moved on to the fault finding guide from Electrosport (Link!) which shows that everything is fine. No problems with the RR or the stator, and no connection issues. I'm assuming this means I have an intermittent ground somewhere up in the wiring harness. My current plan is to (because it will need to be done eventually anyway) order a MOSFET regulator and wire the +\- outputs directly to the battery, bypassing the harness entirely. Will this result in any problems (overcharging)?

I do have one question, though - if I do indeed have an intermittent ground break (or positive, I suppose, though it seems less likely) somewhere in the harness, are there any problem spots I should specifically look at? I'd hate for this to cause problems down the road.

[Stanleybobly]

Nothing against the Moffet but the numbers shown in the second video are no better then what you get with the standard aftermarket rectifier.

other thing is that the mosfet doesn't get bloody hot. it just stays cold or slightly warm (in the summerheat) which will extend the life of the regulator.

[maro6613]

So I tore my bike / wiring harness all apart, trying to look for any grounding problems or the like. I traced the RR ground wires very far, almost all the way to the headlight. At each step, in addition to visually inspecting for problems, I would tap in and check the both the test point -> battery(-) resistance and test point -> motor/frame resistance. No problems found, and I was jiggling the wires as hard as I could during testing to try to provoke any latent problems. As I stated above, I also checked the motor grounds (both left and right) - no problems there either. If I'm missing any other obvious grounding paths, please let me know.

Thus, my current conclusion is that the current RR is bad 'intermittently' - my charging values were fine, save for the occasional voltage spikes to the ~17V area. From what I know of shunt RR internals, intermittent problems seems a bit improbable, but not completely out of the ball park. Someone who is an expert in these matters, please feel free to back me up / shoot me out of the sky

I ordered an FH010 with the accompanying Furukawa connectors, I'll update after I get everything back together.

Motech - your testing plan was a solid one indeed, but unfortunately I had already cut the RR off the bike by the time I read your post in order to test it, so no dice

[Sid Viscous]

Talk to John/bikpaintr, I believe he can probably accommodate your connector needs too. FWIW, I and many other Aprilia riders I know are running his hardware with very good success and no hacked-up mods.

Yes indeed.