Was left stranded, XJ750 Seca no power to anything need help.

Hey guys new-ish to the forums and in need of some divine intervention. I recently purchased a 1982 xj750 seca for $1100 running and driving (my first bike ever), I've cleaned her up and did some regular maintenance and everything was working. All lcd warnings were taken care of and she was running 100% I rode a couple days then when I was low on gas headed over to my local non-ethanol pump. I turned the key to off filled up and turned the key to the on position and nothing she left me stranded. I have brake lights, license plate light, instrument cluster illumination lights and nothing else no starter no neutral light no lcd warnings, nothing. Normally I would hear something click when messing with the kill switch but nothing now. Shes dead Jim.

Things I've Checked
-All fuses are good tested with multimeter, although one of the wires doesnt show any voltage all others have juice. (fuse box was removed by last owner and replaced with inline fuse holders also not labeled)
-Battery is charged and even tried a brand new one, no change.
-Yes the kill switch is in the run position.
-Jumped the little solenoid connected to the positive terminal and the starter runs but wont start (my guess is no spark)
-Ground connected to battery and engine seems like a good connection.
-Replaced the positive cable with the solenoid attached no change.
-Doing a once over on everything nothing appears burned or damaged
-Push starting was a no go

So, yeah what could cause such a massive loss to power? Main fuse it good when I remove that I lose all other lights. Electrical is such a pain especially for someone new to the motorcycle world. I'm hoping its something easy to repair that I can do, we have a local shop that works on motorcycles but i'll use them as a last resort.

 

Hey Joeoeo,
Your profile indicates you are in North Carolina, where in NC are you? There are several of us local to the Raleigh area that can help. It sounds like you might have a lead on the issue with the no power on the one wire.
John

 

Im in the black mountain / swannanoa area. Raleigh is a bit of a drive lol

 

sounds like the fuse showing no voltage it the ignition fuse.
start be iding your fuses 30 amp main 10 amp headlight 10 amp signals 10 amp ignition and a 5 amp fuse in the headlight bucket.
main fuse should be a 30 amp fuse the main fuse when pulled out will always have a hot side as it comes directly from battery.
the main fuse feeds the key switch.
when you turn on the key the key switch feeds the other fuses.

does your headlight come on when you turn on the key?
if it does then pull fuses untill it goes out label it headlight fuse.

do your directionals work?
if they work pull the other fuses untill they stop working , label that fuse signal fuse

that will leave you with the ignition fuse

this sounds like it may be a sidestand switch problem. when bike is in neutral you should hear 2 clicks the side stand relay and the starter safety relay

find the sidestand relay and remove it it should have a blue mark on it
location
Sidestand (kickstand) relay (blue): frame bracket outbound of LH frame tube, just behind the left side ignition coil.

 

No power to headlight until she runs from what I remember when the bike was up and running, same with turn signals. only have brake running light license plate and cluster illumination. stepping on the brakes wont even turn on the other brake filament.

 

you said you had a fuse , although one of the wires doesnt show any voltage all others have juice.

you have a headlight relay if you use the solenoid to turn bike over the head light should come on.

you may have missed this edit
this sounds like it may be a sidestand switch problem. when bike is in neutral you should hear 2 clicks the side stand relay and the starter safety relay

find the sidestand relay and remove it it should have a blue mark on it
location
Sidestand (kickstand) relay (blue): frame bracket outbound of LH frame tube, just behind the left side ignition coil.


you need to fix the fuse with voltage only on one side bad fuse or fuse holder

 

pull sidestand relay turn key on bike in neutral and see if you have 12 volts at the tci red/white wire. this is feed from ignition fuse to kill/run switch.
it is also what powers the starter safety relay.

 

all above lights not working is run from signal fuse


running light plate lightcluster light run from main fuse directly from key switch.

your key switch has 5 wires 1 wire is from main fuse then when you turn on the key a blue wire turns on plate light tail light . there is a 5 amp fuse in headlight bucket that does cluster lights. there is a brown wire that feeds the remaing fuses

 

ok cool so when I get home from work ill try removing the sidestand relay and see if its getting power. I'll also check the one in line fuse holder thats not getting any power. thanks for the help XJ550H ill keep you guys posted on this thread as I get the bike working.

 

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Ok so no power to side stand relay (red/white) also no power to the ignition fuse on 20vdc reading shows 0.1 (red/yellow) also tested ignition wire before the fuse holder. So it's not the actual holder. Where does this red/white wire run to? I'm guessing battery but I've already replaced the positive cable with the little solenoid. Also have no power coming off of new and old starter relay (blue/white and red/white) connected to positive terminal

 

on the connector that goes to the solenoid blue/white wire goes to the starter button when you press the starter button it makes a connection to ground

the red/white wire goes to the starter safety relay output.

the 10 amp ignition fuse runs up to run/kill switch then down to input side of starter safety relay. when the relay closes the red white wire input is connected to the red/white output wire which runs to the solenoid

do you see the Br(own wire running from key switch to the fuse?
that brown wire feeds the fuses except main fuse. the main fuse feeds the key switch.
find the connector that is on the cable harness coming from the right controler (the one with the run/kill switch).
there should be 2 r/w wires at the connector one wire will be 12 volts going into the run switch the other r/w wire is coming out of the kill switch.
the output r/w wire should be hot with the switch in center run position and no voltage when switch is to left or right of center. check for 12 volts in and 12 volts switable out.

in the wiring diagram run switch is called engine stop switch

 

the starter safety relay (starter cutoff relay gets its 12 volts from the run switsh then grounds through the neutral switch


if bike is in gear and sidestand must be up to close sidestand switch . then the starter safety relay grounds through the clutch switch going into the sidestand switch to ground. that would be the L/Y wire in above drawing

 

I have a question about your battery you said you have a new battery in the bike.

my battery for my 750 has the plus on the right hand side not the left.
what brand battery do you have? and is it hooked up backwards?


the original battery used in the bike had plus terminal on left side as your photo shows.

 

So when I bought the bike the PO had just picked up a new in box battery from walmart its a bit shorter than the stock size with reversed terminals its an everstart, it has enough CCA's compared to the original size. I work at an auto parts store so i also tried the proper size battery with correct terminal orientation and there was no change.

 

My vote is for a fractured main fuse holdng clip. Small cracks cause big problems.

 

And also check ignition switch contacts

 

Clean and lube the ignition switch

 

Thanks for the help guys got a kinda hectic work schedule so I'll try all these on monday and see what I can figure out.

 

Ok so brown wire and red wire connected to the key switch is getting solid power. There is no 12v at either r/w wire from kill switch when the key is in off or on position. With the red kill switch in the not run position and key on one of the r/w (in picture) voltage jumps up from .01 to .1 v I'll take apart the ignition lock assembly and clean the contacts. Still pulling my hair out with this thing guys.

Upon further inspection no fuse other than main 30a is getting 12v. They all read .05 or .1v

 

Took a good look at how the PO put in the inline fuse holders and to my surprise was done properly soldered and heatshrinked

 

Ignition switch looks really new. contacts and all internals were super clean. I believe this is a Maxim style ignition switch, would that cause a problem with my bike being a SECA model?

 

po could have done bad job soldering or just twisted wires together cut back the heat shrink to find 3 live feeds from brown wire.
if you get no voltage after that you may have to unwrap harness tape to find splices to brown wire .
all 3 failing I would clean and inspect the key switch first

 

Right I have already cleaned ignition switch and contacts. it seems really new. Guess now I have to find where the hot 12v brown wire splices off. It doesn't appear to be in the headlight bucket mess. Will do it bright and early tomorrow as it is dark already.

 

it splices someplace inside the main wiring harness.

unfortunetly that same brown wire goes to computer monitor and alternator and rectifier.

 

when you pull the ignition switch put a jumper wire from red to brown on the harness connector that goes to the switch see if you have power at fuse

 

Yeah I had put everything back together after messing around with the fuse wires and ignition switch wires and noticed the red (or brown i forget) was melted on the connector. I cleaned the connector to the best of my ability and everything electrical works now. I have ordered some new connectors and will do it up professionally when parts are in. Today I wired in a new voltage regulator and tomorrow will upgrade the fusebox. hopefully electrical will be done and I can move onto new brakes.

 

update: New regulator I ordered was defective (should of bought from xj4ever ) for fun I hooked up the old voltage regulator and cleaned / fixed all melted charging system connections. with a new multimeter seems like 14.8 is the max charging volts when revving the engine which is in spec. Removed alternator cover and cleaned the copper rings and the 2 brushes were in spec. How important is the gasket that goes in between the cover and the engine? should I remove all gasket material and replace or just leave it? pic is before cleaning

 

That gasket's main job is to keep water out of the housing. I wouldn't run that cover without one but it's hard to tell from your picture what shape yours is in. If it's in one piece then I'd say run it. you can put a little sealant on it, make sure you don't block the weep hole at the bottom as this allows any moisture that accumulates in there.

 

This here along with cleaning usually fixes many charging issues. You can buy just the connections and replace them. I will usually crimp and solder these followed by some heat shrink. Pic is just for reference, might not be the correct part.