TOPIC:

Ok so i'm doing some re-wiring on my KZ750 Twin, and i've got a couple questions. I've been reading through the posts for the last week and just havent found what i'm needing to know so excuse me if it is somewhere in the gigantic library of info on this site and I happened to miss it. So the regulator/rectifier unit has 5 wires coming out of it. 2 yellow, a white with red stripe, a black, and a brown. So the the black is obviously ground and the two yellow go into the rear of the motor. The white looks like it is going to a Y connector and being routed to the starter relay. The brown is going into a box containing three fuses. Basically the brown goes into the fuse and comes out a red/blue wire and the is not connected to anything, so my question is, where is the red/blue wire supposed to go? any help would be great, thanks.

Sounds like you nearly have it figured out. The brown wire goes to a switched battery voltage connection. This means like the Ignition or tail light circuit, something that turns on with the key. Just be sure that the circuit has the same voltage level as the battery, within .5v or the battery will end up being overcharged. The R/R uses this wire to Sense how many volts to deliver back to battery.

So could I run the red/blue that follows the fuse from the brown wire from the regulator through say the Ignition key on/off, so when the bike is turned on it will be switched on? or is there a better location? like maybe connect it with the tail light positive wire like you mentioned? Also how can you tell if its the same voltage as the battery? arent all the lights and accessories pretty much going to be running at 12 volts give or a take a little?

You have to take a volt meter and measure the voltage at the battery, then on the circuit under load, switched on bike running. There can be a drop in voltage do to poor connections, dirty switch contacts, wires that have corrosion, etc. If the brown sense wire sees, say 11 volts, it will think the battery is low and put out much higher, probably 15+ which will overcharge/ boil the battery.

Alright thanks for all the help you have saved me a lot of time and frustration, I'm going through the whole bike replacing the spaghetti nest called the wiring and this one wire got disconnected before I had a chance to see where it went. With its location i'm assuming now that the previous owner had it hooked up through the tail light wire. Also being that it came disconnected as easy as it did it was probably not functioning properly and could possibly explain the fact that the battery is toast from boiling over. I will probably move it over to the key switch. What post would I use on the key switch? the "acc" post? Thanks again for your help.

Its needs to get hooked up so it gets switched on with key when bike is running. The tail light circuit May have less voltage drop than say the Main Ignition circuit. Acc I believe does not turn on the Ignition coils, so would not run in that Position. But if its been rewired all bets are off.

Alright so it sounds like that is gonna be the best bet to go with the tail light circuit after checking the voltage of course. Thanks.

So i'm getting to the part where i'm hooking up the red and blue wire that is fused and origanlly the brown wire from the regulator/rec. and i'm thinking, the red and blue wire comes out of the fuse box and is parallel with the blue power wire also out of the fuse box for the tail light. So they are both essentially going to the same thing right? could I just connect the blue and the red/blue wire and run them to the tail light connection?

Here's link to one of the KZ750 twin wiring diagrams included in KZr FILEBASE.

www.kzrider.com/filebase/doc_download/283-z750b3

Good Fortune!

It would help if you could put the exact model and year in your signature. There were at least three variations on the KZ750 twin's charging system.

Judging by your reg/rec, it sounds like you possibly have an 80 KZ750 G1 or 82 KZ750 M1 twin.

The brown wire is switched 12v from the ignition switch. The brown wire from the ignition switch feeds the reg/rec and many other things like brake light switches, warning lights in the gauges, turn signal flasher, headlight fuse, and more. It also feeds the fuse that then feeds that red/blue wire which feeds the marker lights, gauge lights, and back to the ignition switch to feed the tail light. (The tail light has it's own circuit in the ignition switch since the tail light is also a parking light.)

Just make sure that brown wire has 12v on it anytime the bike is powered up, other wise you can melt the electrical system.

skidooman wrote: So i'm getting to the part where i'm hooking up the red and blue wire that is fused and origanlly the brown wire from the regulator/rec. and i'm thinking, the red and blue wire comes out of the fuse box and is parallel with the blue power wire also out of the fuse box for the tail light. So they are both essentially going to the same thing right? could I just connect the blue and the red/blue wire and run them to the tail light connection?

This is difficult to answer without knowing how original the rest of the wiring is.

No fuses are wired directly to the tail light (in the stock configuration). The tail light gets power from the ignition switch. The fuse for the tail light feeds the ignition switch.

The fuse with the blue wire and blue/white wire is for the headlight only.

skidooman wrote: Ok so i'm doing some re-wiring on my KZ750 Twin, and i've got a couple questions. I've been reading through the posts for the last week and just havent found what i'm needing to know so excuse me if it is somewhere in the gigantic library of info on this site and I happened to miss it. So the regulator/rectifier unit has 5 wires coming out of it. 2 yellow, a white with red stripe, a black, and a brown. So the the black is obviously ground and the two yellow go into the rear of the motor. The white looks like it is going to a Y connector and being routed to the starter relay. The brown is going into a box containing three fuses. Basically the brown goes into the fuse and comes out a red/blue wire and the is not connected to anything, so my question is, where is the red/blue wire supposed to go? any help would be great, thanks.

This was the start of your thread, where is this other wire? Red/blue.
OK I downloaded and looked at the link Patton has so Kindly provided. The Red/ Blue wire will come off of the Ignition switch as hot when key is turned on, which is exactly what you would like. Verify it with your meter or test light. Remember to test for the actual voltage on the circuit, and get as close to the same voltage you measure across your Battery terminals. You may still need to clean your connections, fuse clips and the wiring there for the 20 amp main fuse is a very common problem spot.