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1978 cb750k rained on now all the lights only come on halfway bright

snakemantim

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As the title says I just bought a 1978 cb750k and it ran fine except that one of the carbs was just spewing gas out the bottom. So I decided to do a rebuild. Got the kits stripped it cleaned it all good. During the cleaning process I left my bike out and it got rained on ( they were not calling for rain) I promptly covered it and waited for a new throttle cable. About a week later i put my ( I thought fixed) carbs back on and tried to start it up. I put the keys in and nothing. No lights won't kick start nothing. So I attemped to charge the battery, I think I put the trickle charger on backwards though it did not light up to tell my I had the polarity reversed. Now I can get very very very very dim lights but they are all on all the time even the blinkers. I replaced all the fuses that I could find. Including the flicker fuse. I still get nothing. I am an amateur and feel very in over my head. Any help would be greatly appreciated.
 
It sounds to me like you have a loose/corroded connection somewhere or maybe a short to ground. Disconnect the negative side from your battery and go through your wiring harness. Clean each connection. Use contact cleaner if you desire. Be sure to wear eye protection.
Oh, and check you ground(s) for continuity.
Edit: if you don't own one; get a volt meter. They're $10.00 on Amazon.
 
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No but after disconnecting and cleaning all connections and reassembling them I tried to crank it up and the 2 pin connector straight off the battery started smoking
 
You likely have a short somewhere. That can be a real can of worms to somebody with no electrical experience. Lights being on all the time but dim say the same. The entire system has to be broken up and examined and tested piece by piece. Looking at a possible fire hazard there.

You pretty much always have to charge a new battery unless someone already did it for you. If you yourself poured the acid into it it needs charging.
 
I'm charging it now ( correctly this time), but after detaching and cleaning all connections I get no lights at all. So at this point would it be better to just re-wire the whole thing? The motogear m.2 module seems appealing would that be a good choice?
 
20171120_163705.jpg here is the wire, it is the one disconnected this is the left side while on the bike
 
I think at this point you are so lost that any thoughts of changing up your system are highly misplaced. You are incredibly over simplifying by simply showing us one wire, and the pic shows about 50 of them so you still haven't said anything, meanwhile asking for the 500 page book of wiring.

By your own admission you should be probably looking for someone else to do the work. No insult intended or implied at all but to work on them there is at least a certain amount of basic skillset required and you apparently don't have that. The wire that began to smoke may have done it based on something wrong several feet away from that wire so you have the entire system suspect at this point. That does NOT mean to tear it all out as most likely the problem is local and small but needs somebody with enough smarts to locate it.

Smarts? If the new battery had enough power to smoke the wire then flipping the current around to charge it just damaged THAT one too, you CAN'T do that. The battery needed to be run 100% fully dead before you flip charge or you create a short inside the battery itself. You may not have done that but what I'm talking about here, there's not enough information coming out of the OP because he has not a clue as to what to even post about.

If your skills are the same on carbs I see BIG trouble on the horizon. Not trying to be mean at all but the reality of it.
 
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You need to learn how to check for continuity (to ground). Start with the plug that is giving you problems. If you get continuity to ground, then you most likely have a short. I would not advise you to trouble shoot with power applied as AMC stated. See if you can print out the wiring diagram then, in a VERY methodical manner, start checking the wiring harness. Example, pin 1 on one connection to the connector on the other end, pin 1. You should get continuity. Take your time.

Good luck,
Al
 
I think at this point you are so lost that any thoughts of changing up your system are highly misplaced. You are incredibly over simplifying by simply showing us one wire, and the pic shows about 50 of them so you still haven't said anything, meanwhile asking for the 500 page book of wiring.

By your own admission you should be probably looking for someone else to do the work. No insult intended or implied at all but to work on them there is at least a certain amount of basic skillset required and you apparently don't have that. The wire that began to smoke may have done it based on something wrong several feet away from that wire so you have the entire system suspect at this point. That does NOT mean to tear it all out as most likely the problem is local and small but needs somebody with enough smarts to locate it.

Smarts? If the new battery had enough power to smoke the wire then flipping the current around to charge it just damaged THAT one too, you CAN'T do that. The battery needed to be run 100% fully dead before you flip charge or you create a short inside the battery itself. You may not have done that but what I'm talking about here, there's not enough information coming out of the OP because he has not a clue as to what to even post about.

If your skills are the same on carbs I see BIG trouble on the horizon. Not trying to be mean at all but the reality of it.

See the reason I posted on here was because I want to learn how to do it and don't have the money to pay someone $1000 plus dollars to fix this bike. I am aware I don't know what I'm doing. I am also aware of how electricity works my problem is that I don't know how all the components on this particular motorcycle fit together and which parts are likely to be causing a problem. That picture is fairly obvious which wire I'm talking about its the only one disconnected. You make it sound like if I don't know don't try and don't learn and don't ask for help. I didn't come on here to be told to just pay someone to do it. That defeats the entire point of maintaining a classic bike as a hobby. Though unlike most people you must have just been born with all the knowledge needed to completely rebuild motorcycles from scrap metal and surely didn't learn anything or ask for any help for your entire life.
 
It could mean that. If you don't get continuity between two ends of the wire, then check both ends of that wire to ground. If you do get continuity to ground, that is your short to ground. Trouble shooting can be very tedious. That's why you need to be very methodical, take your time, document your progress and think. I can be challenging and it can be a complete PITA!
 
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