XS 850 Special has no power when ignition is set to “on”

Just picked up a 1980 XS 850SG. Bike had two previous owners, both kept it in the garage, and in most immaculate condition. Booted right up when I picked it up (engine was cold). Rode it for about 10 minutes, grabbed lunch, then a 10 minute trip home.

Bike sat for about an hour as I worked on some cosmetic things. This bike has both electric start and kick start. I wanted to try out the kick start, so I gave it a couple pumps and it started. It was idling sluggish, so I gave it some “choke,” but the engine died. Then I tried the electric start, and it started up, but then immediately died. I noticed that my lights (headlight, instrument lights) weren’t illuminated like they’re supposed to be when the key is in the “on” position. I took the key out, put it back in, and still nothing - I should mention the bike wouldn’t even attempt to start either.

Left it alone for about an hour to do some research, and my girlfriend (bless her heart) went out and started pressing buttons and switches, and took the key in and out, and was able to get the lights to come back on (she was only fiddling with the key, the start button, and the run/off switch) - I should mention she has never operated a motorcycle. I was able to kick start the bike briefly, but it died when I put the choke on again. Lights were still on though, so I tried the electric start, and it cut the lights again. Once more, my girlfriend starts fiddling with switches and gets the lights to turn on (she might be some kind of motorcycle rainman), and I try using the starter button again, and once more the lights turn off and the bike reverts back to a 500lb paperweight.

Anywho, neither she nor I could recreate whatever magic she used to get the lights to illuminate again, the bike is back to being completely useless, and I’m at a loss for how to proceed. I’ve checked the fuse box (it’s set up like an XJ and has three 10A and one 20A main fuse) and I couldn’t find any faults, but I’ve heard that their could be a separate fuse somewhere else? I put the battery on a tender, and it said it was fully charged - and I was able to boot the bike up earlier with zero issues, so I don’t think it’s the battery (but I can still have it tested).

Suggestions?

 

My first guess would be that the ignintion switch is at fault.
Disassemble for cleaning, and maybe replacement.

 

I’m assuming replacing would require new keys? Think I’d be able to swap in the ignition from my XJ650 Maxim?

 

So I swapped the ignitions from my XJ to my XS, a simple plug n’ play. But I’m still having the same issue. However, my oil light will sometimes illuminate now when I turn the key, but when I press the starter button I hear the solenoid click, and then the lights die. Thoughts?

 

The oil light should come on when you press the starter button as a check that the light works.

The solenoid click is indicative of low battery voltage, or a starter that is in need of servicing.

You should also look at the fusebox to be sure that it's not the cause of the intermittent nature of the problems you are having.
Your Fuse Box -- A Ticking Bomb??? By: Rick Massey
HOW TO: Install an aftermarket fuse box
If you want to keep the original style fusebox the fuse clips are still available, as are reproduction boxes.

 

Barney needs a bit more help than I can give. I'm more of a hands-on person when it comes to fixing electrics.

@Rooster53 , do you have any imput about this?

Barney messaged me with:
So my issue is that my oil light won’t even turn on most times that I turn the key on. If my oil light turns on, I can kick start the bike, but if I try to use the electric start, it kills the bike completely - can’t even kick start it at that point.

 

I took a quick look at the XS850 wiring diagram and it is different than the XJ's in that the oil light is not part of the starter circuit. The only time the oil light should come on is when the crankcase oil is low closing the switch. The oil level switch may be stuck closed, but I would suggest verifying the oil level just to be safe.

Does this kill every light - tail, brake, head, neutral, instrument? If so the earlier suggestions of a defective fuse box or battery are high on the list of items to check. The battery voltage should be checked with a DMM at the battery terminals and the battery cables - a good cleaning of the cables may be needed both at the battery and at the negative ground attached to the engine. Also, look for a separate ground from the engine to the frame and verify a good connection exists.

If all lights are out and the battery and connections are confirmed OK then the main fuse and wiring should be checked using a meter. I would suggest starting by verifying 12V is reaching the main fuse, and if so verify it is exiting the main fuse; touch the meter lead on the fuse holder clips and not the metal part of the fuse to check.

If some lights stay on I would place the kill switch and ignition fuse at the top to the list since they provide power to the starter solenoid. Check the power at the ignition fuse with a DMM to verify 12V exists on both sides of the fuse - check on the clips as above.

If OK check at the R/W wire on the starter solenoid 2 pin connector. This is the output of the kill switch and should toggle between zero and 12V when actuating the run/kill switch.

 

So I thoroughly cleaned my battery cable ends, and all ground wires, eliminating any grounding issues ... unless of course there’s a fault in the cables themselves. Still no lights. So I guess I’ll have to bust out the multimeter and run some of the tests you mentioned. I’ll report back with my findings when I’m able.

 

Unless I missed it, have you checked the voltage of the battery at rest, and when you are trying to start it?

 

Consistent 12.5 v at rest (disconnected from battery). Starting the bike isn’t so much an issue as getting the bike to a point where I can try to start it. When the ignition is on, none of my lights turn on, which means I can’t even try to start the bike because I zero power.

 

Go test for power to and through the fuses first..... as well as the kill switch

 

MAJOR UPDATE ... sort of.

So I ran some DMM tests. I have to be completely honest, I’m still learning and not quite sure what I was supposed to be looking for ... or if I was doing it right. Tested the battery and got 12.2-12.5 volts off the bike. When connected to the bike with the ignition OFF I got anywhere between 9-10.5 volts (sometimes I got 12 volts, but it was rare). With the ignition ON (still no lights or anything) that dropped down to .5 to 3 volts.

When I tested the fuses for power, the main fuse would give me the same readings as the battery (higher when the ignition was off, and super low when the ignition was on). I tested the other fuses too, but was unsure what voltage readings I was supposed to get - and I’m not entirely (read: not at all) familiar with testing for continuity.

Interestingly enough, I was able to get my lights to turn on while testing my battery and fuses with the multimeter. I thought this was a fluke, but when I disconnected my battery to test for volatage and then reconnected it, my lights failed to turn on when the ignition was on - until I began fiddling with the multimeter again. This must mean something?

Once I got my lights to turn on, I made several attempts to kick start the bike which may have worked, but I believe it was foiled because I removed one of the vacuum port caps to gain access to a stubborn screw and forgot to put it back on (my petcocks are gravity fed instead of using vacuum lines [previous owner], and the vacuum ports are all capped off).

I ended up throwing in the towel on kickstarting it because I was getting tired, and I noticed my lights starting to dim. So again I popped off the battery to test for voltage and to throw it on a tender - voltage was normal and the tender indicated that it was fully charged. I then connected the battery to the bike again, and used the DMM trick to get my lights to turn on, but they were still dim, and then randomly bright again, but then almost immediately completely dim (to the point where you could barely see them in the dark).

I really hope this sheds some “light” on my situation. Thoughts?

 

First thing is to take your battery and have it load-tested.

Sounds like a bad battery, first.

If battery tests good, then we look elsewhere

 

Took my battery to get load tested - it was bad. Popped a new battery on and the bike sprang to life. Thanks everybody for all of your help - you’re a great bunch!