Relay voltage question

[MOTOMYSZOR]

Finally I did my relay mod. But I have ,,problem":
When I measure V in original coils installation there is 11,73V while on battery is 12,1V.

I measured it with key turned to ON, ignition switch in ON and voltmeter connected between coils ground cable and red/white power wire from handle switch......

So I have only 0,4V drop? I am the lucky one or .....  

[red]

Finally I did my relay mod. But I have ,,problem": When I measure V in original coils installation there is 11,73V while on battery is 12,1V.  I measured it with key turned to ON, ignition switch in ON and voltmeter connected between coils ground cable and red/white power wire from handle switch......   So I have only 0,4V drop? I am the lucky one or .....  

MOTOMYSZOR,

With no load, voltage can "float" to the highest available value.  The voltage can be a much lower value there, under load.  What matters is the current flow available, not the voltage.  Here is a mental picture: Fill two buckets on a table with water, and have the buckets connected at the bottoms with a pencil-thin tube.  The water level in each bucket will be equal in height, and if you add water to one side, the levels will become equal again.  Use a hole saw to make a hole larger than your thumb in the second bucket, halfway between the water level and the bottom of the bucket.  Keep pouring water into the first bucket, so it stays full, but the second bucket, with the large hole, will never get full because the drain (load) is too large.

When you change from the stock wiring to the relay system, you have replaced the pencil-thin tube at the bottom of the buckets with a fist-sized pipe.  Even though the second bucket has a thumb-sized hole, you can keep both buckets full then, just by adding water to the first bucket, even though there is a heavy drain on the system.

The small "voltage drop" that you see when measuring voltage at rest comes from the resistance of the wires and switch contacts.  You probably would not see such a healthy voltage there under load.  Any voltmeter takes some time to respond to voltage changes, and to read the correct value.  At any instant, the voltage might be zero, but if the voltage jumps up again fast enough, the voltmeter might not show any drop in voltage.  An oscilloscope would show any instantaneous changes in voltage, there.

It's snowing here . . .     

Cheers,
Red

[MOTOMYSZOR]

I know that original wires are very slim....
But most people on forum had around 10V in original installation.

So now I have doubts......
Because in my FJ volt regulator is not perfect and gives 15V on higher revs, I afraid that relay mod can fry my coils...... 

[Mark Olson]

Don't worry be happy,

Before you did the mod you had 15v anyway , The relay mod allows full bat voltage on startups as well as running.  when your voltage starts going to 17v then worry.

[MOTOMYSZOR]

Because electronics is like black magic for me have to ask about transpo regulator modification ....

Popular replacement for OEM regulator is Bosch RE55. But can I use any other regulator with 2 wires (DF and D+) ?
Like this one: http://www.ebay.ie/itm/Voltage-Regulator-14V-55A-BOSCH-9190087003-/151456120535?pt=Motors_Car_Truck_Parts_Accessories&hash=item23437cfed7

[movenon]

I don't know why it wouldn't work. Make sure the case has a good corrosion free ground. Price is cheap enough. Personally I also recommend a cheap digital volt meter mounted somewhere where you can monitor it. e bay item...
George 

[FJ1100mjk]

Because electronics is like black magic for me have to ask about transpo regulator modification ....

Popular replacement for OEM regulator is Bosch RE55. But can I use any other regulator with 2 wires (DF and D+) ?
Like this one: http://www.ebay.ie/itm/Voltage-Regulator-14V-55A-BOSCH-9190087003-/151456120535?pt=Motors_Car_Truck_Parts_Accessories&hash=item23437cfed7

You can't go wrong with a component from Latvia. It just screams quality. 

[movenon]

I don't know why it wouldn't work. Make sure the case has a good corrosion free ground. Price is cheap enough. Personally I also recommend a cheap digital volt meter mounted somewhere where you can monitor it. e bay item...
George 

I should also clarify something about your comment about using    "using any other regulator with 2 wires (DF and D+) ?"  The FJ alternator is rated at 28 amps so make sure the regulator is rated for that.  Not a problem usually, just knowledge.  I have a Bosch IB301 adjustable regulator and seems to work fine. I like mounting the regulator externally.  Removes it from Alt/engine heat,  heat from the regulation it's self and gives me easy control of the output voltage.  With the adjustable unit you can adjust the voltage for the type of battery you have.  Lead acid vs a Lithium.  Probably a minor issue for some.



IMO one of these or some variant is nice to have. http://www.ebay.com/itm/DC-0-30V-Blue-LED-3-Digital-Display-Voltage-Voltmeter-Panel-Motorcycle-01-DFUS-/331348728832?pt=LH_DefaultDomain_0&hash=item4d25ec5c00
George

[FJools]

I was looking at one of these the other day while searching for a suitable panel mount USB socket.

http://www.ebay.com/itm/Dual-USB-3-1-Amp-Charger-and-Voltmeter-Panel-Mount-12V-Marine-Motorcycle-/261733327067?pt=Boat_Parts_Accessories_Gear&hash=item3cf085a0db&vxp=mtr

Not sure if the LED brightness can be controlled as it could be a pain if too bright at night.

[movenon]

I was looking at one of these the other day while searching for a suitable panel mount USB socket.

http://www.ebay.com/itm/Dual-USB-3-1-Amp-Charger-and-Voltmeter-Panel-Mount-12V-Marine-Motorcycle-/261733327067?pt=Boat_Parts_Accessories_Gear&hash=item3cf085a0db&vxp=mtr

Not sure if the LED brightness can be controlled as it could be a pain if too bright at night.

For me it is not to bright at night but I will mention that it is harder to see during the day (bright sunshine).  But it isn't a gauge I have to monitor at any one moment.

Some members like the old analog meters because you can glance at them and get a quick reference. I chose the digital because it is small and hopefully more reliable than the analog meters that I have had in the past on motorcycles.  Its all personal choice.  A voltmeter is handy to monitor battery condition and charging.  I think the service manual puts the upper limit at around 15 volts (that's without me digging into the manual) anyhow when it gets up into that area your voltage regulator is failing and cooking your battery.  Also possably your battrey is weak over working the alternator.

Another tip while if you are working in that area or doing a routine inspection trace the red wire coming out of the generator going to a red connector on the left side. It is around where the battery is. Should be easy to locate look for the red connector. Pull it apart and give it a good look. If you have been over charging that connect might need some attention.  Here is a picture of mine.  Looked OK plugged in but when pulled apart you can see some heat damage. When I changed out the regulator I was a 15.2 - 15.3 volts charging just for info.


That panel looks nice, I might have to update mine ! Ummm   always something.....  
George

[Arnie]

Here's another Voltage Display and USB port device.
I've bought from this source before and their product quality is usually very good.

https://www.dx.com/p/car-2-1a-usb-port-socket-with-voltage-display-for-honda-black-373050

Arnie

[mark1969]

Don't know if its relevant to this thread, but my FJ was charging at upwards of 14.8v to around the 15v mark, and the battery was bubbling after every ride (top up needed) which obviously ain't right or great. I checked the voltage regularly and it was consistently overcharging. Out of interest, it was actually a little worse when the headlight was on.

I changed the regulator to a new Electrex hoping it might help, there was no change in charging voltage.

I then carried out the headlight relay mod using the kit from Easternbeaver. This installs new wiring from battery to headlight.

I also carried out the coil relay mod, this too installs new wiring from battery to coils.

After these changes my battery charging voltage has been more normal at around 14.3 - 14.4v. Now I'm no electrics expert, but I kind of put this down to new wiring creating less resistance or something like that which then affects how the battery is charged. I don't know. Maybe because the system is a bit more balanced it all works better. Like I say I know little about electrics, but can definitely say my charging voltage is now normal after installing those mods. Both of which have effectively given new wiring to important circuits on the bike, so my logic says that must have had an effect.

Out of interest I also get a little voltage drop from battery to coil (engine not running). I think about .05 of a volt, but voltage to both coils and headlight has improved significantly after the mods, which is kind of the idea I know.

I know its not completely relevant to this thread, but maybe it will help someone, I don't know.

[FJ1100mjk]

After these changes my battery charging voltage has been more normal at around 14.3 - 14.4v.  

Somewhere along the line, something good happened when you were doing your mods. I guess the important thing is that you now have a correct, consistent and stable charging voltage.

Never hurts to go through the connections, grounds, switches and such, and clean up those 30 year old neglected points. Bringing them back to good as (or near) new again.

I have also bought a number items from Eastern Beaver over the years. Good stuff.

Congrats!  

[FJmonkey]

I am guessing the wires you replace/bypassed had more resistance than the new ones. That resistance was telling the voltage regulator that the battery was low or the system needed more voltage. Now that the resistance has normal resistance, the voltage regulator is not getting false readings and putting out the correct voltage. Did you notice a brighter headlamp after the mod?

[mark1969]

I am guessing the wires you replace/bypassed had more resistance than the new ones. That resistance was telling the voltage regulator that the battery was low or the system needed more voltage. Now that the resistance has normal resistance, the voltage regulator is not getting false readings and putting out the correct voltage. Did you notice a brighter headlamp after the mod?

Thanks for reply. Yes the headlamp is brighter, which was the plan. I thought of going HID but decided the relay mod was sufficient for me.

The coil mod is worthwhile too for anyone still pondering over it. Ideally a full rewire would be the answer, but it's quite an invasive project and beyond my skills, and expensive for someone else to do, so both the relay mods are a nice compromise, and within my tinkering skills..