Bad regulator?

Hi all,
First off Id like to say Im more than excited to find this site. I just got a 78 kz650, non running. It needed a new battery so I got one. I hooked up both the positive and the negative cables( the large ones) But it turns out that when I hook up the little red/white wire to the battery, it sparks like crazy and heats up. So I figured- its a short. To narrow it down I removed the fuse that hooks up the red and white wire. Still sparked like crazy, so I determined the short must be before it goes to the fuse. So I put the fuse back in and looked around on the diagram... The only other thing it could be was the voltage regulator.. So I unplugged the red/white wire from the voltage regulator and then connected the red/white wire to the battery, no sparks. I suspected theres either a short or maybe the regulator is allowing way too many volts through. So to confirm this I disconnected the red/white from the battery, plugged the red/white into the regulator, and then disconnected the negative side of the regulator (the plastic connector). I then reconnected the red/white to the battery: no sparking.

Check out this picture....
www.geocities.com/boardfu/help.JPG
Could it be a bad regulator? How do I test it?

Thanks guys

Post edited by: boardfu, at: 2006/11/20 05:18

boardfu wrote:

Hi all,
First off Id like to say Im more than excited to find this site. I just got a 78 kz650, non running. It needed a new battery so I got one. I hooked up both the positive and the negative cables( the large ones) But it turns out that when I hook up the little red/white wire to the battery, it sparks like crazy and heats up. So I figured- its a short. To narrow it down I removed the fuse that hooks up the red and white wire. Still sparked like crazy, so I determined the short must be before it goes to the fuse. So I put the fuse back in and looked around on the diagram... The only other thing it could be was the voltage regulator.. So I unplugged the red/white wire from the voltage regulator and then connected the red/white wire to the battery, no sparks. I suspected theres either a short or maybe the regulator is allowing way too many volts through. So to confirm this I disconnected the red/white from the battery, plugged the red/white into the regulator, and then disconnected the negative side of the regulator (the plastic connector). I then reconnected the red/white to the battery: no sparking.

Check out this picture....
www.geocities.com/boardfu/help.JPG
Could it be a bad regulator? How do I test it?

Thanks guys<br><br>Post edited by: boardfu, at: 2006/11/20 05:18

That is actually a regulator and rectifier in one unit.
You pretty much tested it the most definitive way. The rectifier portion is most likely shorted. You could also do the same test by disconnecting the black wire on the reg/rec, but it would be safer to do a diode check on the regulator. I think you'll need a new reg/rec. It is a single-phase reg/rec for a permanent-magnet alternator.

Here are some other KZ650 models using similar reg/recs.
1978 B2
1978 C2 custom
1978 D1 sr
1979 B3
1979 C3 custom
1979 D2 sr
1980 E1 LTD
1980 F1 custom
Some may use a different connector and some may have an additional brown wire. The brown wire just gets connected to a switched positive voltage source.

Post edited by: loudhvx, at: 2006/11/20 12:16

Ill try a new reg/rec. Thanks.
Anyone else agree?

boardfu wrote:

Ill try a new reg/rec. Thanks.
Anyone else agree?

Boardfu...if Loudhvx says it,I don't think too many will argue.He's one of the the electrical Guru's around here,and He certainly knows His stuff.
THAT...I agree on.

Welcome to KZR,btw!:woohoo:

OO Nice. In that case Im honored. Thanks guys.
Ill letcha know how it goes after I get the reg/rec.
Im new to motorcycles so hopefully I can say this KZ will be my first ride. Thanks,
John

I think if you get that baby running you will have a smile on your face from ear to ear. I still do!

Oh and by the way we must have pictures!!!!

Pics? Will do!