At what voltage should regulator kick in?

[79josh81]

So I recently bought a solid state Electrosport ESR350 (has the two plugs) reg/rec for my 1979 xs650.

Everything in my charging system is stock 1979 stuff (so from what I understand I should not need nylon screws). The wires on the two plugs are as follows: the rectifier portion has 3-whites, 1-black, and 1-red. The regulator portion of the plug plug has 1-brown and 1-green wire. According to Electrosport, this reg/rec should be "plug and play" with my stock charging system. Plug and play my ass.

So anyways when I "plugged and played" it, I got no charge whatsoever. After messing around with it for a while, I removed the reg/rec's red and black wires from the one plug so that the only wires that were in that plug connected to the stock plug were the 3-whites. I then ran a jumper from the reg/rec's red wire directly to the positve battery terminal and then ran a jumper from the reg/rec's black wire directly to ground. Still nothing.

So then, I disconnected the reg/rec's black wire that I ran directly to ground and just let it hang in the air so it wasn't being used. I left the reg/rec's red wire still jumpered and connected directly from the reg/rec to the positive battery terminal. I started the bike and now it is charging.

Meanwhile during all of the this, the reg/rec's regulator plug (brown and green wires) were connected to the stock wiring harness like they should be. Now with the current wire configuration and the battery charging, when I rev up the rpms to like the 4000 rpm mark, the battery voltage will keep climbing higher and higher to the point where I hit 15 volts on the battery so I stopped.

My question is: does anyone know, from what I explained above, why I'm having to leave the new reg/rec's black wire not connected to anything to get a charge? And also what is the highest voltage the regulator should allow the battery voltage to charge to before it kicks in and starts regulating how much voltage the battery receives from the charging system?

 

[5twins]

The "set" point or peak output varies slightly on regulators from different manufacturers but is normally in the low to mid 14's range. About 14.2 or 3 is said to be ideal for recharging a 12 volt battery without over-charging it. So yes, 15+ volts is bad and wrong. It appears the regulator portion of your combined unit may not be working. Your alternator could be running unregulated and full blast. That may be because you don't have a ground wire for the regulator. The original had one, as did the rectifier. On these combined units, it seems there is only one ground wire to the unit and it is shared by both components inside. That's a problem for you because if you connect the ground wire, the unit doesn't function at all. I'd say it's defective.

When you get tired of dealing with these expensive, low quality combo units (or you reach the bottom of your wallet, lol), I suggest doing what many of us do - use a low cost automotive regulator and a rectifier from the electronics industry. You can usually set those up for from $20 to $40.

 

[79josh81]

Thanks for responding 5twins. I was hoping you'd see this because I know you know the electrical on these bikes as good as anyone. Yes, sick of it to say the least. I do have a cheap rectifer that you guys showed me that works good with the stock regulator for charging. The reason I went to the combined unit was to save space and minimize the electrical components on my bobber build without having to go to a PMA.

 

[5twins]

Yes, there may be no way to "have your cake and eat it too" in that regard. But it's only one extra component. The automotive regulator is similar in size to the combo unit and doesn't get that hot in operation. You could probably put it inside your fake oil tank. The rectifier does get hot so it's probably best not to bury that inside a sealed box somewhere. But, if you cut a hole in the bottom of your fake oil tank, maybe you could mount the rectifier and it's wiring in the box and just let the cooling fins of the heat sink hang out through the hole. The rectifier I'm using is from a place called Windy Nation. It's quite compact and you could probably get away will a smaller heat sink than I used .....

https://www.windynation.com/Rectifier/35-Amp-3-Phase-Bridge-Rectifier/-/218?p=YzE9MjA=

 

[79josh81]

Thanks for the info. And yes, "cake and eat it too" has been not happening for me with the stock charging system. As far as the regulator in the fake oil tank electronics box, do you think the stock regulator gets too hot to put in there?

 

[79josh81]

Hey 5twins, while I have you here, do you know how I would get rid of the safety relay on my 1979 xs?

It hasn't been working since I bought the bike and I've tried two other safety relay units with no success. Right now I have it jumpered (blue/black to red/white) so that my head lamp at least works, but without the relay I have no electronic start. Do you know how I would have to run the stock wiring by the relay to get my electronic start back? Is there any wire running into the relay that I can jumper directly to the starter solenoid to get it to work? I really wish I could wrap my head around how the electricity flows in and out of every wire and what colors carry what on the bike but I'm just not there yet.

 

[5twins]

I think that long green resistor running down the side of the stock regulator does get pretty warm. I can't say if it would get too hot being enclosed in a box. But, as far as upgrading the charging system components goes, replacing the regulator is an important one. That old mechanical regulator works but it's output is very erratic. Replacing it with the car one greatly reduces the strain put on the alternator and rotor, the two "big ticket" (expensive to replace) items in the system.

The safety relay is actually a double relay, 2 relays mounted on one bracket. One is for the headlight and the other for the starter. I don't like the headlight auto-on one but I do think the starter one is a good idea. It prevents the starter from working once the motor is running. The relay makes or breaks the connection on the R/W power wire running to the solenoid. So, to bypass the relay, you would simply have to jumper together the 2 R/W wires in the relay's harness plug. But, now you won't have that accidental start protection any more. Personally, I would keep using the starter portion of the safety relay and just bypass the headlight portion. The headlight relay has power fed into it on the R/Y wire from the headlight fuse. Power runs out of it on the blue/black wire to the reserve lighting unit. In there, it is sent up to the hi-lo switch either on the blue/yellow wire or the blue/green wire (if the low beam fails). To bypass the headlight relay, simply jumper the R/Y to the blue/black in the relay's harness plug. The headlight will always be on now, unless you install an on-off switch for it somewhere further up the line.

 

[79josh81]

Thanks you're the man. I would also not mind having the starter safety relay working but, for whatever reason, that starter safety relay won't work either with any of the safety relays I've tried. I can always still activate the starter motor via the electronic start button no matter if the bike is running or not. I think the problem might be the yellow wire coming from the stator not supplying enough voltage to trip the relays. When I have the relay plugged in, the electronic start works but the headlamp won't. I'm assuming the starter portion of the relay is normally closed and the headlamp portion is normally open until power is fed to the relay via the yellow wire from the stator, which then opens the starter relay (disabling the starter) and closes the headlamp lighting relay (gives you power to the headlamp).

 

[5twins]

Yes, that's how it works. So yes, it does seem like you're not getting a voltage signal, or enough of one, on the yellow wire. Have you tested it's length for continuity? Maybe there's a break in it somewhere between the alternator and the relay. Have you tried to take a voltage reading off the yellow wire when the bike is running?

I don't think a full 12 volts gets sent through that yellow wire, nor do the relays require that much voltage to be tripped. You have a 3 phase alternator. I think the yellow wire just runs from one of those phases so only sees like 5 or 6 volts.

 

[79josh81]

No I haven’t. I think I read somewhere the voltage is supposed to be like 6volt on the yellow? How do I test it? Just multimeter red to the yellow wire and multimeter black to ground while the bike is running?

 

[5twins]

Yes, basically it would be just like taking a voltage reading off your battery.

 

[79josh81]

I just checked it and I’m only getting 1.1v max coming at the yellow wire coming directly from the stator so I’m guessing that’s the issue. Not sure how to fix that wire other than completely removing the stator and seeing if I can replace the yellow wire somehow.

I’m not ever sure if that’s possible with messing up the stator.

 

[5twins]

The yellow wire is two parts. You have the section coming out of the alternator and running up to the multi pin plug on the alternator harness. It's not fed into that plug, it's a separate wire with a bullet connector on it. Then you have the second section running from there through the main harness to the safety relay. If you're lucky, maybe it's just that bullet connector. Maybe it's loose, dirty, or corroded. Try the voltage test at that connector too. If you get a good reading (about 6 volts), then the yellow wire coming out of the alternator is OK, it's the section running to the safety relay from the bullet connector that's bad, or the connector itself.

 

[79josh81]

Yeah I tested it before the bullet connector on the stator side so it’s something wrong in the yellow wire that comes directly from the stator.

 

[5twins]

I'd test for continuity on the yellow wire between where it goes into the alternator and the bullet connector. The sleeve it runs through is jammed in around the sprocket pretty good and it's not unheard of for wires in that sleeve to get pinched, cut, or broken.

 

[79josh81]

I have to give that a go quick.

 

[79josh81]

Well I have continuity from the relays yellow at the connector to the bullet connector before the stator. Unfortunately I can’t get to the yellow wire at the stator to test from the stator to the bullet connector. I’d have to cut the yellow wire’s insulation inside the stator to get to it.