Topic: Rectifier Regulator Smoked burned - could it be caused by

[Spanner 1]

Don't open your alternator !... if there is no voltage on the White wire from the reg/rect unit then no proof anything is wrong with the alternator ( very rarely is ). The Green wire from the rect/reg must be grounded as does the Green wire from the field coil. I would connect the R/R Green to the field Green that comes out of the alternator ( It's the green wire in the 8-way connector-has 3x yellow , white, light green/red and brown/red ) and MUST connect their junction to a solid ground .
7.5 ohms is a perfect reading for your field coil ( it's not a rotor ), so that's good .
I hope I'm explaining this good !... See the Green wire that comes out of the alternator goes to one end of the field coil winding ( White being the other end ) BUT the Green wire does not connect to ground in the alternator, it has to connect to ground externally, and it does in the stock wiring set up but NOT if you just connect it to the new R/R green which also must go to ground... phew 

[Knightro]

spanner one, thank you for your response. I would agree with your advice opening up that part of the bike should only happen if you really need to... I did before I read your post... realised I was able to test everything fine without doing that and my tests were coming back good.  That being said, my clymers manual says to open that puppy up to do any tests on it... bad advice... shame clymers.

SO, your post is a little confusing. You see my reg/rec up above, (i posted photo) there is only one green wire, and that fits into the stock wire block which before went to the stock rectifier... That is where the green ground field coil wire connects in the stock set up... ... or is this where i'm getting confused...
the green wire that would normally connect to the stock regulator (Which i thought went to ground, but is that the green that is supposed to connect to the field / green from the alternator/generator?  In my new reg/rec there is no connector for that green ground which was before on the stock regulator. The best I can find online is that the unit grounds through the body of the reg/rec. So I have taken that green wire from the old regulator, put a different connector on it so that it fits nicely onto a mounting bold for the reg/rec and i'm using that as the ground at this point for the reg/rec. (though, again, I can't get it to work properly when set up this way)....   YOU say that field coil wire should not go into the block connector but that it should go straight to ground, and then i presume you suggest the green wire from the reg/rec should also go straight to ground?  Have you used this reg/rec before? and that set up worked?

After reading my response is it more clear what i'm doing wrong/right?

others suggested it was a ground issue early in this thread.... All my grounds have very low resistance...    .002  or .0018.

[Knightro]

I did want to mention here, though this sounds like a plug, it is just a fact... www.vintagecb750.com the place I got the original reg/rec combo unit which started smoking... has responded to my complaint. They are sending me a  Rick's Electric with instructions. they said if that one burns, its cause of my bike, but i think my bike checks out... so I hope this is all because of a bad reg/rec. ...

Still. I now have 2 of these reg/recs and I would like to just get it to work... especially seeing as how I have another old bike that could use an update.

So I have to say, I am very happy with Vintagecb750 and would recommend them to anyone especially a Canadian as they are in Canada, we don't pay duty but we do pay american which is a pain in the but...

[Spanner 1]

That R/R unit does not ground thru' the case mounting screws, that's why it has a green wire needing to be connected to ground. Same with the field coil green, it must be connected to ground.

Lets recap on what wires go where. First cut off that white connector.
The 3x yellow go to the 3x yellow in the 8-way connector ( the half of the connector whos wires go into the alternator ).
The Green wire goes to ground.
The Red wire goes to the battery +
The Black wire goes to any convenient Black wire on the bike
The White wire goes to the White wire in the ^ above connector and
The Green wire in the ^ above connector also goes to ground 

[Knightro]

thank you for the clarification.

one last thing which may be causing my rec/reg to burn out... is this tidbit of info which I get from Ricks motorsport electrics.... however I don't really see a 'cause/fix' anywhere for this occurrence.

The occurrence is this:
- The voltage on the black sensor feed wire is greater than a .4Volt drop from the voltage reading I'm getting between the batter terminals. It's more like a .6v drop. that from what I understand, will cause my alternator/rec/reg to constantly try to send increased voltage to the battery. causing early fault in the battery and possibly burn out the Reg/Rec.

I believe the info I have says this is due to loose or corroded connection somewhere on that black sensor wire... but that is part of my whole bike harness....    Is the fix for this simply running a fresh wire from ignition hot (black wire) to somewhere on the bike... somewhere ... remains to be determined by me...

Or am I missing something...

[TwoTired]

What you are missing is attention to all the connectors and switch contacts between the battery and the black wire connection to the regulator.

Cheers,