TO3 alternator regulator - Page 1
Forum section: electronics / repair

author: Thermoelectric
author_rank: Contributor
timestamp: September 18, 2020, 11:08:33 am
content: Hey all,Got an alternator off a 1996 Kawasaki ZZR1100, which is charging high at about 15.3v. Looking into the repair manual states that resistance between the regulator terminals should be in the 100's of ohms to 10's of K ohms, and testing showed in the megaohms on most of them.It's based on a TO3 package labeled 3R18 which I can't find anything on. Connected to battery positive as a sense, ground and the output to the field windings as control.Anyone know what I might be able to use in its place? Ideally the same TO3 style would be best, but any self contained device I could hack in its place would work, though I'm not sure what type of device this would be. I'd imagine it's effectively just an op amp driving a transistor in the linear region to control the field windings.(photo with the pinout of the TO3 - F(field) is the device case, E(ground) and IG(ignition) are the pins.Cheers!

author: rvalente
author_rank: Frequent Contributor
timestamp: September 18, 2020, 12:29:24 pm
content: I was very surprised to see a bike with an alternator, hum, usually it is just a dynamo...Check this "tecgauss" there is a bunch of schematics of various regulators, you may find something similar to your case, as there is codes, can cross reference for something sold in your area, don't bother it is in portuguesehttps://www.gauss.com.br/tecgauss/informativos-tecnicos/

author: orbanp
author_rank: Regular Contributor
timestamp: September 18, 2020, 12:38:09 pm
content: Bosch used TO3 style regulators on their alternators in the '80s.It was built together with the brush assembly, usually brushes wore out, and the controller was still fine.You can buy those (new) regulators cheaply, or just get a junk alternator and remove the regulator.If you are interested I can give you more details about those regulators.That those regulators are for automotive alternators with higher currents does not matter, those regulators are "voltage controllers" for 12V lead-acid battery charging alternators, the current supplied depends on the wiring of the alternator itself.Regards, Peter

author: Thermoelectric
author_rank: Contributor
timestamp: September 18, 2020, 12:40:21 pm
content: Hey Peter,Any more details on those would be awesome. Looks like an easy way to go about getting a similar part!Cheers.Beau.

author: mikerj
author_rank: Super Contributor
timestamp: September 18, 2020, 12:48:12 pm
content: Quote from: rvalente on September 18, 2020, 12:29:24 pmMost bikes have permanent magnet alternators where the rotor doubles as the engine flywheel, there are quite a few that use car style alternators with field control though.The ZZR1100 will have a Denso alternator, the guts of which are used in many other applications. Thisaftermarket regulatorseems a little pricey, but it does give you a big list of other bikes you could get a regulator from.

author: orbanp
author_rank: Regular Contributor
timestamp: September 18, 2020, 12:50:13 pm
content: Hi Beau,Here is some excerpts from the Bosh Automotive Handbook from the early '80s about alternator regulators.That should give you the info on those regulators.If your alternator has permanent magnet, as the previous poster suggests it might, then this regulator would not work, it only works on alternators with field coils.Regards, Peter

author: drussell
author_rank: Super Contributor
timestamp: September 18, 2020, 01:25:17 pm
content: Wow, those prices on a 026000-7050 regulator module are insane!With modern cars, the regulator is often in the main engine control computer / powertrain control module, whatever it happens to be called. If one blows up for some reason or misbehaves the official fix is to "replace the computer" which is often very expensive, or try to repair it, etc.My suggestion to people in this situation where they have a costly regulator is to just use the old Dodge style external regulator. (External, as in mounts to the firewall instead of on or inside the alternator itself.) It simply needs +12V and is grounded by the frame, then one wire goes out to control the field. Super easy, dirt cheap, essentially universal voltage regulator. You used to be able to get them for about $7 in the isles of any auto parts store, wasn't even usually a counter item.These days, they're up to more like $25 CDN but it's still cheaper than replacing a computer.https://www.rockauto.com/en/moreinfo.php?pk=45629&cc=1072459&jsn=557Unfortunately, it's probably a bit physically large for mounting on your motorcycle since it's meant to control the field on alternators making up to 120+ amps, which obviously you don't need.Finding a similar one, though, from an alternator style that uses an internal / on-alternator regulator module should net you a new one in the $20 range, though. You just need to find a model of alternator that uses a similar one that is common enough to have the regulator assembly readily available at low cost.For example, the module used on the Bosch AL33X (used on some Volkswagen and Audi vehicles) above isn't terribly helpful since the regulator is integrated into the brush assembly:https://www.rockauto.com/en/moreinfo.php?pk=45678&cc=1369751&jsn=511&jsn=511However, another possible alternator design for those same cars has a regulator made by Motorola, and it is a separate module that is physically small:https://www.rockauto.com/en/moreinfo.php?pk=45669&cc=1369751&jsn=512The problem is that those are still rather expensive (About $60 CDN here), though since those are European car models, they might be significantly cheaper on the OP's side of the pond.HERE, I would try to find some common GM or Ford part or something, but there it may well be cheaper to find some common Bosch part.Well, that or repair the one you have or build your own. It should be pretty straightforward.

author: mikerj
author_rank: Super Contributor
timestamp: September 18, 2020, 03:47:40 pm
content: Spanish webpage showing someone hacking aBosch regulator into the Denso assembly. The Bosch regulator is from the integrated brush/regulator assembly like the one drussell linked to above.

author: drussell
author_rank: Super Contributor
timestamp: September 18, 2020, 04:20:56 pm
content: Quote from: mikerj on September 18, 2020, 03:47:40 pmHey, yeah... There you go, since they are apparently the whole integrated regulator circuit in that TO-3-like package, just get one of those and bodge it onto your plastic frame thingy.Amazon has various replacement brands of those "Bosch Style" 14V4 regulators starting at about $11.It shouldn't be difficult then, to just remove your flakey regulator and install a new one. Problem solved.(Well, assuming your problem isn't actually a bad connection on the 12V through the ignition switch, a bad ground or something causing it to regulate incorrectly because it "sees" the wrong voltage even though the actual regulator is good. I assume youhavechecked the voltagesatthe alternator vsatthe battery to ensure it's actually well connected to the battery, has a good ground, etc. so that it will actually be reading the right voltages, etc., right?)Edit:to correct typo

author: Thermoelectric
author_rank: Contributor
timestamp: September 18, 2020, 05:22:04 pm
content: Legends! That page you just linked about hacking the 14v4 Bosch is funnily enough exactly the same alternator that's on this bike. I'll have to check again, I thought I tested the case of the TO-3 to be different (maybe field?) for the bike whereas it looks like ground on the the Bosch style, however that web page doesn't seem to think so.Thanks all!

author: fzabkar
author_rank: Super Contributor
timestamp: September 18, 2020, 07:59:08 pm
content: I would check whether the field is grounded (as in Chrysler autos) or connected to battery/ignition. That will determine which type of generic replacement would be suitable.

author: drussell
author_rank: Super Contributor
timestamp: September 19, 2020, 12:40:00 am
content: Quote from: fzabkar on September 18, 2020, 07:59:08 pmUhhh, no...On any electronic-regulator Chrysler I've seen, like my giant monster B350 van for example, the alternator field is supplied with ignition-switched +12 and the regulator pulls the other side of the field (the green wire) down towards ground to make more charge juice.

author: fzabkar
author_rank: Super Contributor
timestamp: September 19, 2020, 03:32:26 am
content: My Chryslers were verrry old, long before the regulators became integrated into the alternator. I was thinking that one would need to look for very old regulators in order to find a discrete unit.

author: james_s
author_rank: Super Contributor
timestamp: September 19, 2020, 06:01:30 am
content: That looks exactly like the regulators in my Volvos. The only time I've had them fail it was the brushes that wore out, in one case I got an OEM and in another case an aftermarket replacement, both worked fine. There was also a plain brush pack with a separate external regulator used in the earlier cars, it fits in the same alternator.

author: Thermoelectric
author_rank: Contributor
timestamp: September 19, 2020, 06:29:54 am
content: As an update for all those interested...Originally assumed the regulator was faulty as it was well out of spec compared to the readings in the book, however we measured the actual voltage it was seeing on its supply pin as suggested by a previous poster. Funnily enough it was seeing 14.2V while the battery was at 15.1V. Used a temporary jumper wire to bring the battery voltage directly to it and the charge voltage dropped to what was expected.So, turns out that one was likely fine and the readings just aren't what the book says they should be. Now to try and chase down 1V of drop across a wiring harness and ignition switch.Occam's razor strikes again.Once again, thanks all!

author: drussell
author_rank: Super Contributor
timestamp: September 19, 2020, 12:13:23 pm
content: Quote from: fzabkar on September 19, 2020, 03:32:26 amI don't think Chrysler has ever really used alternators with built in regulators. Newer ones are still usually external regulation, just not a separate regulator module on the firewall, they're integrated into the computer. (My Dakota is like that with the 318 Magnum. It uses a Nippon Denso alternator but still has a small red and green wire directly to the field winding.) In my '78 van wiring it's an external box on the firewall. Well, I have two of them since I have two seperate charging systems, alternators and batteries. The main one for the van and the auxiliary to a big group 31 deep cycle for the stereo.It's also very handy if something goes wrong with an electrical system or you accidentally drain the main battery or something. You simply jump-start yourself.My '83 Dodge Challenger's (which is actually a Mitsubishi Galant Λ, Lambda) original 2.6L engine's alternator has a little black plug-in voltage regulator module on the alternator itself, but that's a Mitsubishi. Once I get around to actually putting my spare 360 V8 in there, it will finally have the soul of a real Challenger.(Curb weight on those cars is only 2767 lb, so even once I add the weight of a roll cage it's gonna be really,reallyfun!)Newer designs based on Mercedes or now Fiat stuff may have used internal regulators, but most now have the field externally controlled by the engine computer (Powertrain Control Module as Chrysler usually calls it.)Chevrolet used a lot that were internal to the alternator, even the commonly-retrofitted "one wire" alternators where you don't even need to give it switched ignition, just the one big wire to the battery. Many ford alternators also have a regulator module bolted to the alternator.

author: drussell
author_rank: Super Contributor
timestamp: September 19, 2020, 12:22:02 pm
content: Quote from: Thermoelectric on September 19, 2020, 06:29:54 amIt is likely the ignition switch itself, contacts going high resistance on ignition switches is a very,verycommon problem. Often older-style ones can be relatively easily disassembled and contacts cleaned and polished up if you catch them before they go thermonuclear and char up the contact holders.The fact that the module doesn't match the book isn't always surprising, later versions with different, more modern circuitry often don't match those simple ohm readings from contact-contact on things like voltage regulators or ignition boxes, so always take that with a grain of salt.... especially in a case like this, where it seems to still be regulating, but just off somewhat, it doesn't make sense that it would actually be totally bad if it's still regulating. Sure, something as simple as a resistor driftingcouldcause it to not regulate to the correct voltage, but that won't cause ohm readings to be that far out of whack... It's obviously a different design. Those ohm meter checks are meant for people who lack basic electronic understanding and are lucky if they even have a ohm meter for checking things. We can do much better.Anyway, glad you figured out that it's not actually the regulator, and yeah, like you say, always check the easy background stuff first before blaming things like the regulator, since it was doing exactly what it was told.