Topic: Replacement Regulator/Rectifier CHEAP

[Pinhead]

The regulator case might get hot and the battery won't charge. I doubt you'll get any smoke, though, due to the electronics being inside the box.

[Alan F.]

Here's a wiring diagram from the 76-78 Ford F-Series pickups, since this is the application the VR730 is sourced from, this diagram may prove useful.
-Alan

[Pinhead]

Yes, that verifies my original thread.

A - Battery +
F - Field
S - Unknown
I - Ignition Switch

But only in that order.

In other words,


1 - Battery +
2 - Field
3 - Unknown
4- Ignition Switch

[cosmo]

Would you happen to have updated links for the rectifiers?

[Pinhead]

This one will probably work.

http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=160392160573&rvr_id=&crlp=1_263602_263622&UA=%3F*F%3F&GUID=c65886af11f0a0b582d314c3ffe48b2b&itemid=160392160573&ff4=263602_263622

I'll try to find a more "permanent" link.

Here's one from Digikey:

http://parts.digikey.com/1/parts/1695246-rect-bridge-gpp-800v-50a-scvb-sc50vb80-g.html

Or from ICSUPPLY:
http://www.icsupply.com/itemdetail.asp?partnum=3572699&mfg=INTERNATIONAL+RECTIFIER

[cosmo]

This one will probably work.
...

Thanks for the links, is there a range of specifications to stay within?  

[Pinhead]

The CB750 alternators are what, 200 watts? That's only about 14 amps max at 14.4v so pretty much any rectifier that can handle that should work.

I'd say 35 amp rectifiers are plenty cheap so I wouldn't go any lower. The voltage should never go above 14.4v if the regulator is working but I'd stay with 50v or higher to be safe.

[Slams77]

I just finished installing the vr730 on my CB400F.  At idle with the headlight off and using a mulit-meter it registers at just above 12v and just above 13v at around 2500 – 3000 rpm, but as soon as I turn the headlight on it drops to around 10v and seams to continue to drop.  When I give it throttle the headlight gets brighter and then starts to dim.  Is this still to be expected after installing the 3 phase rectifier and the solid state regulator?  Not sure if it makes a difference, but the PO installed an H4 headlight….could this be the reason for the voltage drop?

[Pinhead]

This could be due to a number of problems. I don't know about the power capability of the CB400 specifically, though. The regulator can NOT make the alternator put out more power than the field coil/stator is capable of. More stable power, yes, but not more power.

Are you using the original wiring harness/plugs? If so, you may have resistance in the wiring between the alternator and the battery. This is why I've always ran extra wires straight from the rectifier to the battery (both pos and neg).

Your ground wire looks to be adequate.

I don't know how you color coded your wiring, but it looks like it could possibly be wrong... On your regulator, "I" should go to the battery positive, A should go to the field coil, S is unused, and F should go to a "switched" source (ignition switch).

Don't ask me why they switched the letters around. Just remember that the letters can be anything but the wiring harness that they plug into will always be the same.

[Slams77]

Thanks Pinhead,
The connectors on both the old harness and rectifier were worn and cracked so I removed them and attached female connectors to the harness then went straight to the rectifier.  If I run extra wires from the rectifier to the battery “+” and “-“, do I just leave the two (red & green) wires from the harness unused? I tried hooking up the regulator in order from left to right and as soon as I turned the ignition to the on position it got very hot instantly.  After this I hooked it up a couple of the ways listed in this thread (even back to the left to right sequence but it didn’t get hot the second time around, wonder if I fried it?) and the results were all the same.  Any way to test regulator?Could the H4 bulb make a difference in voltage loss? 

[Pinhead]

I personally used the original wires and added the wires straight to the battery.

When I was experimenting, any time the regulator got hot, it was fried. :/ I got lucky and only did that once, though, and it was because I didn't run a ground wire from the casing to the neg battery terminal.

The H4 bulb will make a difference but not as much as you are indicating; it should still be able to charge above ~3000 RPM.

I'm curious, what year of Ford did you ask for when you got the regulator? I just noticed that the PDF file that Alan F. posted was labeled '76-'78. This possibly means that outside of that date range, the wiring could be different. My regulator was from a '76.

Does anyone have access to a wiring diagram for a pre-'76 F150?

[TwoTired]

H4 is only a style specification.  From an electrical standpoint the wattage rating is what is important.
For example, if you put a 100 W bulb in place of 50W, you will draw twice the power from the battery, and the alternator can only put into the battery what isn't consumed by the bike.
A properly working alternator doesn't always make peak power, only at optimal spinning speed, which is not at idle.  If the bike consumes 230W with all the electrical loads, the alternator will never charge the battery.

[Alan F.]

I couldn't find any free diagrams for a 75, but here's a link to the diagrams from a 74:  http://www.fordification.com/tech/schematics_h.htm

They're huge and this little laptop screen is getting a little blurry after all of this searching....
-Alan

[Pinhead]

Thanks, Alan. I'm going through the diagram for the '74 to see if the regulator should be wired the same but they're in a different "format" than I'm used to so it may take me a little while.

[Slams77]

I really didn’t get a clear answer from the clerk other than it should work for Ford vehicles ranging from 71 to around 84.

[Alan F.]

I'm going through the diagram for the '74 to see if the regulator should be wired the same but they're in a different "format" than I'm used to so it may take me a little while.

Yeah, if it was the same format I'd have gone deeper into it myself.  But on a little laptop screen it was pointless to even try.
-A

[vbtiki750]

I am finally getting back to try this setup again and i just wanted to recap some of the info i've received.  First of all I am rebuilding a 76 750 that hasnt ran since i've owned it, the wire harness is missing so I  have to make a harness for it.  I've got the bridge rectifiers and the vr730.  Queeg helped me out on the fuse in the vr730 battery+ wire and the 15 amp fuse on the rectifier battery+ wire.  Now i just need to know if I need to bypass the oil light and the neutral light wires coming from the rotor plug to fire the bike for the first time I thought I heard somewhere that if the neutral switch wasnt engaged the bike wont run the starter.  I dont plan to have any indicator lights so i've got to get rid of these wires. 

I was also curious if the starter case being off the bike while i tried this would make the starter not ground out.  I thought maybe the starter grounded out from the case bolts that run through it. 

Can I combine the wires coming from the vr730 and rectifiers that go to the place, i.e. battery + wires grouped together and batt - wires grouped together. 

Thanx for any input

[vbtiki750]

BTT

[Pinhead]

I am finally getting back to try this setup again and i just wanted to recap some of the info i've received.  First of all I am rebuilding a 76 750 that hasnt ran since i've owned it, the wire harness is missing so I  have to make a harness for it.  I've got the bridge rectifiers and the vr730.  Queeg helped me out on the fuse in the vr730 battery+ wire and the 15 amp fuse on the rectifier battery+ wire.  Now i just need to know if I need to bypass the oil light and the neutral light wires coming from the rotor plug to fire the bike for the first time I thought I heard somewhere that if the neutral switch wasnt engaged the bike wont run the starter.  I dont plan to have any indicator lights so i've got to get rid of these wires. 

I was also curious if the starter case being off the bike while i tried this would make the starter not ground out.  I thought maybe the starter grounded out from the case bolts that run through it. 

Can I combine the wires coming from the vr730 and rectifiers that go to the place, i.e. battery + wires grouped together and batt - wires grouped together. 

Thanx for any input

I don't have a CB750 so I can't answer your first few questions.

However, you can combine the wires that all end up in one spot (i.e. battery + and battery - ). Remember, however, that the "combination" will be carrying the collective current from all of the components so larger gauge wire may be needed.

[Alan F.]

Hey Doug did the diagram from the 74 ford reveal anything?

[Pinhead]

Hey Doug did the diagram from the 74 ford reveal anything?

It revealed that I don't really know how to read the old-school diagrams. 

I'm trying to go through it again right now though so I may come up with something.

[Joel]

Is there any way to calculate how much heat these rectifiers dissipate?

http://www.guerte.com/en/Products2/PDetail.aspx?ID=12497

[TwoTired]

Is there any way to calculate how much heat these rectifiers dissipate?

http://www.guerte.com/en/Products2/PDetail.aspx?ID=12497

Yes, but not with those specs.
You need to know what the forward v drop is, and the current passing through it.  That will give you a watts consumed/dissipated, which you can convert to BTUs.

But, that seems like an odd request.  What are you going to do with a BTU per hour specification?  You installing an Easy Bake oven on your bike and going to heat it with the rectifier?

[Pinhead]

Is there any way to calculate how much heat these rectifiers dissipate?

http://www.guerte.com/en/Products2/PDetail.aspx?ID=12497

Yes, but not with those specs.
You need to know what the forward v drop is, and the current passing through it.  That will give you a watts consumed/dissipated, which you can convert to BTUs.

That's what I was thinking but you beat me to it.

But, that seems like an odd request.  What are you going to do with a BTU per hour specification?  You installing an Easy Bake oven on your bike and going to heat it with the rectifier?

LOL!!!!

[Ryan6838]

 Is the VR730 a solid state regulator? And in the one diagram it shows to rectifiers is there a modal that can be used to just run one. I just learning on wiring so im a little lost here. Im replacing all the connectors on the bike and was wandering if i can wire these up using the stock wiring alone? Sorry if i ask something thats been answered here somewhere.