What does a regulator do !!!!

[Phoenix]

Hi All , Im hoping the engineers amongst you, which appears from the job descriptions posted recently seems to be a lot, might be able to answer the following query: When my 99 @ is ticking over with no lights on the battery charges at about 12.9 volts going up to about 13.5 when the engine is revved, however as soon as the lights are switched on the charge rate visibly drops to 11ish. And when the engine is running with lights on, the lights do not brighten when the engine is revved. I would be grateful for any suggestions; Im tired push starting the bike cause the batterys flat.

[icenian]

Hi All , Im hoping the engineers amongst you, which appears from the job descriptions posted recently seems to be a lot, might be able to answer the following query: When my 99 @ is ticking over with no lights on the battery charges at about 12.9 volts going up to about 13.5 when the engine is revved, however as soon as the lights are switched on the charge rate visibly drops to 11ish. And when the engine is running with lights on, the lights do not brighten when the engine is revved. I would be grateful for any suggestions; Im tired push starting the bike cause the batterys flat.

I'm not a (proper) engineer but I've had exactly these symptoms from a sh*gged battery.

Of course it could be the generator or the regulator/rectifier (which should control voltage), but start with the cheapest and most likely solution!

[robelst]

Spooky, but I had the same problem (amongst others) last week.

The battery had "July 1998" written on it, so I replaced it with a fresh new Yuasa. Then I drove to Holland and then the fuel pump started playing up, AND the battery was not loading properly AGAIN (fading lights on dash) I was not sure if the fuel pump was causing a general electrical problem but I had to leave it on because a by-pass prooved to be even worse. I disconnected one of the headlights and that seemed to help, battery got enough juice to fully reload itself.

So: I still have a crappy fuel pump, one headlight working and quite a happy battery. Not sure what is wrong yet and what the errors/causes are, as soon as I get the funds together to buy me a new fuel pump I will probably learn more soon
(probably the regulator, that's about the only part left that hasn't been replaced the last few weeks )

[landyandy]

Hi there,

It's most likely to be your 'regulator/rectifier' - this is an ecu box located towards the rear of the bike.

I replaced my battery in June (and engine, and most other things), and found a couple of weeks ago that the battery was going flat. It would only get enough volts if I ran with no lights etc.

I bit the bullet and bought a new reg/rec from David Silver Spares, which cost about 100 quid.

Now the charging system is around 14.x volts, which'll do for me.

If you know someone else with an AT, the easiest test would be to try one off another bike - it's 2 bolts and 2 connector blocks.

Cheers.

[robelst]

Oh joy, in few months time new headstock bearings, new front brake-pistons & pads, front-fork revision, new clutch & cable, full service, exhaust repair, new rocket cover gaskets, new tyres, new battery, new chain & sprockets, fixed lame mirrors, new fuel cut-out relais; still looking for funds to have the fuel pump replaced, wheels are rotting and now the rectifier to look forward to?

Interestingly I bought the AT as a backup for my 42.000 miles Buell... which has not missed a beat since I got the Honda (which is good, because that is the bike that is doing the miles at the moment).

Ah well: If you have any old bread or used razor blades left, don't bin it but send me a PM please

On the positive side: Riding with one headlight helps to keep my battery happily charged for now, so maybe it works for you too? It is surprising how little difference it really makes lightening-up the road, although I have to add that my maximum speed is 65mph at the moment (fuel pump problem!) so I have more time to see where I go in the dark

[robelst]

Hello,
Still have a charge-problem when running with both headlights on (gradually drains the battery).

I did some measuring today: Battery reads 12.7 V (ignition off), after engine is started I measure 13.5 (idle), goes up to 14.5 at 4000 rpm. Looks perfectly fine, innit?

When I switch on one light I read 12.3 V, when revving to 4000 rpm it jumps straight to 13.0 and then very slowly goes up to almost 14 (takes more than half a minute which is a bit strange?). Enough to keep the battery charged which it does indeed.

When I switch on both lights it starts at 12.2, revs straight to 12.4 but never gets higher. 12.4 is below the 12.7 of the battery's "base" voltage, which explains the battery being drained.

Battery is new (just replaced, because I thought it was causing the problem in the 1st place). Also tried another light bulb (you never know) but hardly any difference. I also have the fuel pump that has hick-ups and buzzes straight after the ignition is switched on.

What do you think? Regulator? Alternator? Fuel-pump short-cut?

Thanks!

[robelst]

(sorry for subtly kicking this topic back to the top of the list )

Regulator: I am in the sad process of getting to terms with the fact that I may need a new regulator (or is it "rectifier")?

Before I splash out on that just this question:

I have had problems with regualtors twice on bikes before in the past, and on both occasions the result was a much too high charging voltage, boiling the battery empty and other inconvenience. In this case I can only see a drop in voltage as soon as I switch on the lights. Are "we" sure this IS a rectifier problem, in other words, has anyone had the same problem and fixed that by replacing the rectifier? Is there any way of measuring certain components?

Thanks!

[jabba]

Erm this is from my own personal experience but as you know the rectifier changes ac to dc the idle rate I have found on most bikes in the past is 13.5v which in theory is enought to charge the battery and feed the bikes components anything over 14 volts I would think would constitute a risk to the cdi ect as they are voltage sensative ie dont ever jump start your bike from the battery if your useing a car battery ect always use the main feed off the starter solanoid that way the bike generates its own power from the spin not the outside source.
If your battery boils the rectifier is the first culprit as its over charging.
Also make sure your battery is the right wattage you never know if its too small it will cook seen this numerous times batterys are bike specific! I had a wet cell 12 amp on a zr1100 it should have had a 16 amp needless to say it was flat all the time and when it did run it would cook through over charging coz the jenny was too strong for it the battery was fine just couldnt cope with the bike. Found this out because of acid venting onto the loom NASTY! all because the previous keeper wouldnt spend £50 on the proper dry cell!
Erm I dont think I have helped at all here have I?

[robelst]

Thanks for your reply. It is not the AT that overcharges the battery (doing 14-ish Volts max, which is similar to what landyandy mentioned). Fried batteries happened on a Buell and a BMW once, measured anything there between 10 and 25 volts! Clear regulator related. On the AT all is fine until lights are switched on, looks like an overload more than a typical regulator problem, more like the alternator, or a "leak", or maybe the faulty fuel-pump (going to replace that, so I will soon find out).

I already needless spent 60 quid on battery and 34 on a fuel cutout relay that were both still working , do not want to spend another £100 on a regulator unless I am dead sure the thing is dead.

[samih]

I came across the same problem twice this year (with the old and new regulator, changed the regulator "just in case" before my 6000-mile summer holiday).

The connector from generator (three yellow wires, under the left-hand-side side cowl) had started to melt due to corrosion and resulted in the connector to partially melt. This resulted in one of the generator's three phases to go out and a low (about 12V) voltage. This slowly drained the battery.

I redid the connector block with fresh crimp terminals and lots of electrical tape. I hope that has fixed it for good.

See this picture from another AT that suffered from the same problem:

http://www.allroadtour.fi/muotka2003...es/image13.htm