Overcharging

I recently experienced lights dimming out at night and checked my voltage output. It was 13.5-14V at idle. When I revved to 4000 it was at 17, I changed the voltage regulator out and I'm still experiencing this issue. Is it possible that it could be the separate rectifier? This is a brand new battery.

1977 KZ1000A

The rectifier shouldn’t cause this, what is the voltage on the brown wire at the reg when the bike is running? 

Clean all ground points and connector contacts in the regulator/charging circuit. A high resistance ground or connector can cause a regulator to increase voltage output.

You say your lights were dimming out BUT your voltage at battery shows 17V? That's counterintuitive. Some things to initially check. That "Brown" Regulator wire Wookie mentioned is included along with 3 more that are housed within the same "Green 6-hole connector Male connector" but only 4 locations are used in this block. These Junction Box connections are often problematic because of the thin barrel tinned terminals used. So verify this push-in connection is well... connecting. Also make sure the single Black wire running from the Regulator isn't just connected to the battery box. Battery box is NOT a good ground, it's isolated with rubber dampers so it "floats". Correctly Ground to either engine or frame as ckahleer was trying to say. Don't know what "replacement" you used? Often these days they sell combo Regulator/Rectifiers. These take the place of both units and package them as one. Change of original wiring required of course. The original Regulators have always been a weak point in these Z charging systems. They superseded them from the beginning because of symptomatic over-charging, that's why you see a lot of acid staining on a lot of ole bike pipes because the batteries boil over. When You replaced, did you just replace with another old used original unit? Keep up the faith, minimal components here! Have FuN!          

Here are a couple pics of what is going on with those 4 different colored female connectors behind it's bracket. Note Brown wire from Regulator also goes to the White/Rectifier Female connector but isn't connected to anything. What IS an important connection is where it routes to the Main Harness Brown female connector block. So you can have two points of weak/non-existent connections. Brown to Main Harness has that Q-tip resting on it. Just stuff you can see and understand before you rip into it.      

   Mama Kaw went through multiple iterations of those separate voltage regulators during the Z1 era because overtcharging.  KZ1K's should have the final version @ 14.5 v.  The only way to tell which is which is by an ink stamp on the paper tag.  The stamp is faded on the one in the pic, so there's no way to tell what version it is.  If the stamp can't be read, it's a crap shoot what one ends up with if buying used.

   Those separate regs were never designed to charge a low battery; they fry themselves passing that much current.  They're more like crude battery maintainers.  Our experience is, keeping the battery fully charged between rides will make those old-style regs last a very long time, provided every connection is electrically sound.

   There is a process to test the separate regs under power, but it requires an external, adjustable DC power supply, something uncommon in hobbyists shops / garages.

Good Ridin'
slmjim & Z1BEBE

I think unless you are "heavily wedded" to keeping it 100% original, switching it out for a later combined unit will be more reliable

It was replaced with a good condition oem regulator with verifiable stamp, but assuming by looking at the work that was put into this bike over the years this was an ongoing issue without resolve.  Soldered 10 gauge grounds to frame, it looks to me the connectors were cleaned, and dialetic grease applied. This bike looked great as it sat when I purchased it. But I'm getting the never ending project vibe from this machine. Full top end rebuild, spacers incorrectly seated in swingarm, bearings, etc. Ive owned my share of bikes but this one takes the cake. But when it runs this dog can still hunt.

Pleva87 wrote:

It was replaced with a good condition oem regulator with verifiable stamp, but assuming by looking at the work that was put into this bike over the years this was an ongoing issue without resolve.  Soldered 10 gauge grounds to frame, - why ?? a single 10awg ground is adequate for the whole bike except the starter. Won't the flux used during soldering cause the frame to corrode ? (running them back to the battery would have done the trick) Do you still have a 6awg or similar from the motor back to the battery ?  it looks to me the connectors were cleaned, and dialetic grease applied. This bike looked great as it sat when I purchased it. But I'm getting the never ending project vibe from this machine. Full top end rebuild, spacers incorrectly seated in swingarm, bearings, etc. Ive owned my share of bikes but this one takes the cake. But when it runs this dog can still hunt.

PS: bike looks great

I should have re read that message theyre bolted to the frame but longer grounding paths soldered rather than using crimp connectors. The guy was very through on checking the connections and also giving me a hosing on the engine. I understand its not the most viable option but im considering what I read in a previous forum. Removing the brown wire from the connector and spitting it with a switch and fuse to the terminal on the battery. I don't want to buy a aftermarket junk R/R and run into other issues as some hace reported.

I hope you understand I’m just trying to help, be careful what you take from Forums and check the credentials of the person offering the advice (I have seen some wild stuff on other sites) I am an auto electrician with over 40 years experience. As previously mentioned check the voltage on the brown when it’s connected and operating ( the brown is the main ignition live for everything so if you need to by-pass it on the reg you have a resistance issue that needs resolving 

Something to consider, givin' the bike is anything but original. Upgrade to a "series" type R/R replacing the ole "shunt" style. Ness has a whole write-up on it somewhere. I use them all the time on bikes like yours when "rivet" counting originality isn't soo important. I keep these two pieces on hand, R/R and it's matching cable in case i need them. And, it's Not a crappy Chinese Aftermarket replacement. You are correct though, lots of those 14.99 Amazon piles of poo out there ha. Superior "clipped" consistent output thru the rev range. Food for thought.. But like Wookie stated!! If bulb is dimming, probably headlight, for no other apparent reason. You have some sort of "other" wiring issues going on!!