Need help with wires getting to hot on my Xj750?

So had this bike in my garage growing up and I never really knew what it was. It was always just a motercycle to me that was always there. Now that I'm older Ive been dreaming of getting a project car or some kind of project to work on. Turns out it was in my garage the whole time. It's such a beautiful bike with only 5k on it. It was my grandpa's and he gave it to me dad. He worked on it a lot when I was growing up but never rode it. I have decided to take the project on and make this bike run.
We have been able to get it running just fine. The last issue my dad had with it was some of the wires up front started melting as well as the 3 white wires on the other end of the generator. Going to the regulator. We have tested almost every wire and can't figure out what is going on. We know for sure it's not the generator putting out to much and the regulator is working that's brand new we replaced that part and we still are getting hot wires. The wires I could find up front that were getting how were red and blue looked like they went into the ignition but we took that apart and it was all clean.

I'm curious if anyone has had this problem before or would have any idea where to check next? As it always goes with electrical it only take one bad ground to mess it all up.

Just as an add on this bike has all the ferrings so it has extra wiring that goes to the lights and ciggeret lighter.

- Jacob.T

 

start with the 3 white wires, look at the plug, does it look like it's melted at all? that plug gets corroded and hot. you can replace it with 3 separate connectors or get a original
from chacal at xj4ever.com
the fuse box on these is just old, it's best to just replace it. those things might fix the other problem

 

Thank you, the connector isint burnt up it might be dirty though. For the fuse box everything seems fine as far as I can tell. I'll take a closer look at it all though.

 

heat is there because of excessive amp draw. dirty connectors bad battery old glass fuse box every contact point creates resistance and heat dirty contacts more resistance more heat.
clean battery connections motor ground and any other connectors.

 

More resistance equals less current...
You have a short circuit somewhere - is the regualator good - disconnect the output and try it again. If the white wires are not getting hot your problem is after that - look at the feed wires to your main fuse and to and back from the main switch. Ultimately your fuses are there to stop this happening, so maybe someone bypassed one of them? They are pants though - get a blade upgrade asap, and get to know your manual and wiring diagram.
I will say again - you have a short, not a bad earth or dirty fuses.

 

The resistive heater in my garage makes a lot of heat with very little current draw. Dirty connections do get hot.

A short circuit should also be checked for though.

 

"The WIRES are melting, not the connector, simple physics. What has your garage heater to do with this kmoe?

 

I cleaned the connectors and we started the bike again same issue as before. This time we found that the main wire in the fuse box was getting hot as well so we need to upgrade that. Where would you find a blade fuse box for this bike? I searched Dennis Kirk and found nothing as well as service Honda. Any information is appreciated.

- Jacob T

 

www.xj4ever sells a nice kit . His site has an. Email address.

Bike charges battery through main fuse. Check out battery conditkion and connections.
http://www.xj4ever.com/clean and lube the ignition switch.pdf
Above link is how to clean ignition switch.

 

You don't need to upgrade any wires, just the fusebox itself. - any blade auto fuse bix will do, but if Chacal has one I'd buy that. @XJ550H has a good point about the battery - try charging it on a charger see how it likes it. Something is loading up your system, and it could be the battery, on the other hand it it could be a wire trapped somewhere or someone has added something. Fixing the fuses will make it worse, ironically.
I did suggest you got a wiring diagram, and learned to read it - did you and can you?

 

Yes I have a manual for the bike and I have been looking at the diagram it helped us pin point where the issues could be but when we look for shorts we cant find any. The main fuse box wire has been getting hot as well so ill get an upgrade for that. One other spot I am curious about is the cigarette lighter its like my dad disconnected it at one point and I can find where its supposed to connect if it needs to be at all. Is this something that needs to be connected? the ground wire seems to be connected but there is a positive wire that is just sitting there free.

 

no cigarette lighter came on the bikes.

what wires are getting hot melting?

pull the headlight and signal fuses this will eliminate them as the system pulling amps.

what 750 do you have?

what is the voltage with bike at idle and at 2k rpm?

have you ohmed out the charging system? checked diodes in voltage rgulator?

by up front do you meen in headlight bucket?

red is it solid red? blue dark blue soild color?

 

It is a 750 seca. The wires that are getting hot are the three white wires on the regulator side not the ones coming from the generator. The other wires are the ones that go to the ignition. The main red and brown and blue (all of them are solid color) The lighter is on the front ferrying. it is aftermarket to my knowledge.


hopefully these pictures help. Im sorry I cant give the best resonances this is all a big learning experience for me.

 

Now this latest post is a mystery - the three white wires ARE the ones from the generator. They are the ac output from it.
Ac 3 phase in, dc regulated out. Or at least that's what should be happening. Now, you could have a duff rectifier/regulator, which is putting out AC, which would not go down well with the battery, and might well cause an overloaded dc wire, but I would expect at least 2 of the white wires to also complain?
Did you disconnect and put a charger on the battery?
If you did, and it was Ok, try the same thing on the bike, battery connected, ignition on but bike not running - what does the charger amps show? If all is good with this test I would be seriously doubting the rectifier/regulator.

 

I thought he mentioned that the melting was occuring to the wires at the connectors.

 

Well if you can't find a short after the switch it must be the regulator or the battery......
Please let us all know?

 

Hola. Sé que es una publicación anterior, pero tengo curiosidad de cómo se resolvió ya que tengo el mismo problema con esos 3 cables blancos. Gracias

 

you say you replaced the regulator/rectifier, are you sure it is the correct one for the bike, and are you sure it is not faulty. test the rectifier with a multi-meter ,for a short to ground, on the pins with it disconnected, theres a guide on here somewhere on how to test out the charging system.

 

I don't see any mention you measuring the voltages in the charging system. I'd say it's time to get a voltmeter and start testing. I always recommend using this fault finding diagram from electrosport (start at D) https://cdn.shopify.com/s/files/1/1091/5694/files/fault-finding-diagram.pdf?235929069374954073

The white wires from the stator should be rated to handle the current output of the stator. They may get warm, but not hot. Usually the insulation will protect the wire from deterioration, but the ends where the connectors are crimped can start to corrode. On my Turbo, I ended up recrimping (i.e. shortening or replacing) just about every wire in the charging system to reduce resistance in the connectors. However, if the AC voltage output is too high from the stator, this could also heat the wires. The stator is regulated by the brown wire, and if this wire isn't close to the battery voltage, it can cause the RR to overperform. But that's just a guess and you should perform the testing above.

 

Muchas gracias por tus respuestas y por el archivo, es muy didáctico. Me pondré manos a la obra y luego te cuento.

 

Problem solved, it had false contacts in connectors and parts with sulfate.
Thanks a lot!!