Black rubber box behind battery?

[Maxx650]

Hey guys,

I was putting on a new tach and speedo this weekend and also fixing a few wiring issues at my console/headlamp while I was at it. I'm looking to totally rewire the thing this winter to clean it up as it has a million extra wires and dead ends and who knows what from the PO.

I was tracing back some wires - I believe my console 'brake tail light' wire, a black one with a red strip and it went back to a group of wires behind my battery to a plug I realized was kind of tucked away and not too noticeable - I noticed it was unplugged from it's female end which ended up going to this black rubber box behind the batterybox and just ended there -a few wires ended there.

All I could make out from the black box was "Rotto 12V" or possibly "Rolto 12V".

Any clue what this is?? I didn't pull it out because it was kind of a hassle to and I plan on doing the wiring in a month.

Forgot to mention:
1979 XS650 Special

Thanks!

 

[racerdave]

Reserve lighting device I think

 

[angus67]

those are grey.
Is it about 1 inch by 3 inches? with a opaque yellow end to it? looks like epoxied shut?

 

[gggGary]

Sounds like the lighting checker, one of those "not so" good ideas.

 

[Maxx650]

You nailed it gggGary - that's exactly it. What is its purpose?

 

[racerdave]

light checker or reserved lighting device as I called it, don't they turn on the high beam if the low beam burns out?

 

[gggGary]

In 79 they had both reserve lighting and light checker. I think it mainly lights the brake and tail light bulb out warning light. WTH???

View attachment 527

 

[racerdave]

Ok, both of mine are in a box of "WTF do I do with this stuff" now

 

[gggGary]

Yeah, if you rewire, that's a good spot for them till you get tired of tripping over it and trash can it all..

 

[angus67]

big bertha that pos into the neighbor's yard

 

[bluebikerblan]

Self Cancelling Turn Signal Unit, Reserve Lighting Unit, Light Checking Unit (SCTU, RLU, LCU). Three separate units. The first two are plagued with reliability issues. Each/all have marginal utility versus reliability issues especially as a function of aging.

SCTU ...just unplug and remove. RLU...unplug, remove and connect blue/yellow to blue/black. LCU...unplug, remove and make new connection to supply power to tail light from blue wire circuit of choice depending on when you want tail light to come on (when ignition circuit is activated or after starting).

Trace out a surprising number of now unneeded/unnecessary wiring and want to build a very pretty pile of multi-colored wires.

Of course you are going to be left with some new responsibilities like:

Turning your turn signals ON and OFF manually with your left thumb and looking to see if your Headlight is ON or OFF. Ditto your tail light.

With practice, I assure you that these challenging new tasks can be mastered and in time you will know why so many call these near useless sources of electrical reliability issues were called the "bells & whistles" of the XS 650 "Specials".

Ditto also the side kickstand down ignition cut out switch of the later year "Specials" whenever that was introduced and whatever it's actually called? I've never had one or dealt with removal.

Opinion: Unless you have strong desire to preserve the bike and all it's apparatus in it's pure stock state, a lot can be gained by simplifications along these lines and then doing some good cleaning, re-soldering connections as necessary and protecting the contacts and connectors with di-electric grease. Replacement of the old style glass fuse box with the new blade type with box is also a given.

Blue