No electrical power

[QTreiber]

Finally the snow is gone and I was getting ready for a ride on my 1979 XS1100F.

I kept the battery charged with a trickle charger.

As always the bike started up right away and - as almost always - the engine died after about 2 seconds. Normally I just hit the starter button again and the bike starts again and runs just fine.

Not this time. There is no electrical power whatsoever. No blinker, lights, horn.

The kill switch is in the RUN position, all fuses are OK, the battery has 13.1 Volts.

Because there is battery power and nothing works is the ignition switch the next item to check? If yes, how...?

Any help is appreciated!

Greetings from the Front Range,
Armin

[BA80]

Check your battery connections, you may have a corroded or loose connection.

Your main power fuse may have blown or gotten a bad connection also. I know it's under the left cover on an 80 special but I've actually never looked on my 79.

[TopCatGr58]

Greg I'm surprised!

The main fuse for the 79's is in with the other 3 fuses in the block, it got moved to a separate circuit like you said in 80!

As has been suggested, check the grounding cables for corrosion, however as you stated, it DID start. So..either main fuse...most likely especially IF you haven't done the solid ATCO fuse block MOD and are still using the glass fuses and OEM holder, or your main key switch has gone bad/corroded!!

However, 13.1 volts may still be just a surface charge, how old is the battery? If 3 years or so, it could be suspect and you may need to get it load tested!

T.C.

[BA80]

Greg I'm surprised!

T.C.

Gimme a break. I haven't even LOOKED at the SF since last september. Gotta get to work on it also.

That's where I thought it was but wasn't sure enough to send him there.

If there are no lights or anything it most likely lost connection somewhere. If it started once it should at least have the voltage to light the twinkles.

[QTreiber]

Greg I'm surprised!

As has been suggested, check the grounding cables for corrosion, however as you stated, it DID start. So..either main fuse...most likely especially IF you haven't done the solid ATCO fuse block MOD and are still using the glass fuses and OEM holder, or your main key switch has gone bad/corroded!!

However, 13.1 volts may still be just a surface charge, how old is the battery? If 3 years or so, it could be suspect and you may need to get it load tested!

T.C.

Thank you for your quick responses!

The main fuse is fine. I also checked it with an Ohm-Meter. I bought the bike with an aftermarket fuse block (no glass fuses). Looks OK.

I tightened the battery and ground connections.

The connections should be good. I checked with the voltmeter: I held the black cable probe to the engine block and the red wire probe to the red cable at the starter solenoid and it read 13.0 Volts.

Can main key switches fail suddenly or are there any other potential causes?

What is the best way to check the main switch? Do I have to remove it?

Armin

[crazy steve]

Can main key switches fail suddenly or are there any other potential causes?

What is the best way to check the main switch? Do I have to remove it?

No, you don't have to pull the switch. Take out the headlight and locate the plug to the switch. With the key off, you should have battery voltage on the red wire going to the switch. If not, the problem is the fuse/fuse panel/or the wire from the fusebox. If you do have power, turn the switch to on; now you should have the same voltage on the brown and blue wires. Check by sticking your meter probe into the plug next to the wires, and check both sides of the plug; sometimes the plugs go bad. No power out of the switch or if the voltage is lower by more than a few tenths of a volt, you'll need to replace or rebuild the switch.

[crazy steve]

One other thing to check; pull the fuse and make sure you have battery voltage to the fuse. There's a wire coming off the positive battery cable that's the main feed to the bike. There's another plug connection in that wire, make sure it's good...

[QTreiber]

One other thing to check; pull the fuse and make sure you have battery voltage to the fuse. There's a wire coming off the positive battery cable that's the main feed to the bike. There's another plug connection in that wire, make sure it's good...

This one I checked... There is full voltage going to the fuse.

I will check the main switch. Are OEM main switches still available? Are they hard to rebuild?

The battery is of unknown age. It came with the bike when I bought it 2 years ago, so it is a suspect. However, shouldn't at least some lights come on?

It cranked the starter without any hesitation right before the power went out.

Thanks again for all your help!

Armin

[QTreiber]

No, you don't have to pull the switch. Take out the headlight and locate the plug to the switch. With the key off, you should have battery voltage on the red wire going to the switch. If not, the problem is the fuse/fuse panel/or the wire from the fusebox. If you do have power, turn the switch to on; now you should have the same voltage on the brown and blue wires. Check by sticking your meter probe into the plug next to the wires, and check both sides of the plug; sometimes the plugs go bad. No power out of the switch or if the voltage is lower by more than a few tenths of a volt, you'll need to replace or rebuild the switch.

OK, I have full voltage (same as on battery terminals) on the red wire in the headlight bucket on both sides of the plug.

When I turn the switch to ON the voltage interestingly goes from 0.00 to 0.05 at both the blue and the brown wires and that's it.

New switch...? Are OEM switches still available or is it worth making the effort to rebuild the switch?

I am just glad this happened in the garage and not somewhere in the canyon!

Armin

[fredintoon]

New switch...? Are OEM switches still available or is it worth making the effort to rebuild the switch?
I am just glad this happened in the garage and not somewhere in the canyon!
Armin

Hi Armin,
one time I had to get trailered 150 miles back home after a total electrical failure. Turned out that squirting the ignition lock with contact cleaner was all that was needed. Guess what Mr. Stupid didn't pack in his toolkit?
If your switch is fubar MikesXS has one that should work for you.
Or my son's fragged XS750 may still have a good switch he'd sell you.

[QTreiber]

Hi Armin,
one time I had to get trailered 150 miles back home after a total electrical failure. Turned out that squirting the ignition lock with contact cleaner was all that was needed. Guess what Mr. Stupid didn't pack in his toolkit?
If your switch is fubar MikesXS has one that should work for you.
Or my son's fragged XS750 may still have a good switch he'd sell you.

Thank you, fredintoon,

I just went to the garage and squirted the ignition switch with contact cleaner: no immediate effect I'll check again tomorrow morning.

I have never opened/cleaned an ignition switch. Is this pretty straightforward?

Armin

[crazy steve]

...I have never opened/cleaned an ignition switch. Is this pretty straightforward?

I haven't personally done one, but there is a thread somewhere about rebuilding one; you'll have to do a search. But you can still get new ones (I see them on eBay all the time for about $30) if you don't want to hassle with it. The only downside is you can end up with multiple keys....

I'd take a shot at rebuilding it, what have you got to lose?

[CaptonZap]

Thank you, fredintoon,

I just went to the garage and squirted the ignition switch with contact cleaner: no immediate effect I'll check again tomorrow morning.

I have never opened/cleaned an ignition switch. Is this pretty straightforward?

Armin

Howdy Armin,
Yep, get a baking pan, line it witha towel, get a selection of screwdrivers, and REMEMBER the order and orientation of the parts.
You can even take the lock apart, and rekey it, with some patience
One of the things that endears these bikes to me is that you can take them apart, repair them, and put them back together with common tools. Yell if you get stuck. CZ

[CatatonicBug]

Rebuilding the switch is not all that difficult. Here is a thread with a link to a pictorial. Just follow it step-by-step, and you'll have a nice, clean switch. Even if that's not the real problem, it never hurts to clean out the old electrical connections on these bikes.

[ManagerMike]

Disassembling and cleaning the switch is rather easy, however after the first time I did it, it started misbehaving again after about 4 months (bike would shut off on its own without warning).
After the second cleaning the following season, it went gremlin on me again after just a few weeks
Now I have a toggle switch hidden behind the RH side cover that can only be found by touch (without removing the cover of course) and a nifty place for a clock