R80ST Electrical Problem--please help

[KatieR80ST]

I have a 1983 R80ST in very good condition. It just moved from Atlanta to Rhode Island...along with me...courtesy of United Van Lines. They removed the cowling and disconnected the battery. The bike was crated. Upon arrival here we reconnected the battery and the bike is dead. The accessory plug works but there is no power to the ignition. We tested the battery--it's fine--as are the two fuses. We took the gas tank off and looked for any wire breaks but found none.

The bike ran fine three weeks ago. I'd really appreciate any thoughts you guys may have. Thanks.

[SteveD]

Welcome Katie.

I'm not too familiar with the st, but here are the things that come to mind.

Kill switch? Jiggle it lots to clean its contacts.

Has something come off the ignition switch when they removed bits?

Jiggle the fuses in their holder, or replace anyhow. Sometimes the older connector surfaces can play up. The st has more modern fuses than the usual 8amp ceramics that were used doesn't it?

[Airbear]

Hi Katie, and welcome aboard. Think of it as an opportunity to get to know your bike's electrical system. It will probably be something simple.

My suggestion is to get one of these if you don't already have one. Only a few dollars from your local auto shoppe.



With the alligator clip attached to the frame or engine, you can probe around to see where you have 12V power. The ST has a red wire going from the battery positive to a 7 way junction somewhere, and all power for ignition, lights, etc is derived from this. There are also a couple of multi wire 'earth' junctions that, if detached, will mean no circuits can work. It will probably be something simple.

Do you have a wiring diagram for your bike? There is a good colour one in the Haynes manual. If you don't have that, shoot me an email and I'll scan it and send by return message.

[ME 109]

I'm thinking the key ignition switch.
A wire off, or incorrectly placed, or loose.

ZM, 'electrical' thoughts!
(Pre-emptive strike)

[Airbear]

ZM, 'electrical' thoughts!
(Pre-emptive strike)

Excellent!

[Jean]

Airbeear, the 12v testers you can get in the US don't look like that one you show;
they are usually an "Ice-pick" arrangement with a huge plastic handle that encloses the little test lamp.
If Katie goes out looking for one of what you have in your photo, she will need to hop a plane to the Old-country!!

I think when they removed the cowling (WHY did they want to DO that???) they disconnected something...rather carelessly.
FIRST guess has to do with the neutral switch/light terminal on the start relay. That might have gotten pulled off the start relay...it gives "permission" for the starter to operate. since the neutral light is on the cowling, it is the thing that springs to mind...The HAYNES sechematic shows this wire set as brown with black tracer.
Likewise, the clutch switch might have gotten pulled out of its housing at the clutch lever. Same trouble as with the neutral switch.
Does the neutral light come ON when you turn the key ON and the trans is in neutral??
BTW, the HAYNES also indicates the R80T only goes thru 1984, but depending on when the bike was bought and titled, the year can change.

[Airbear]

Airbeear, the 12v testers you can get in the US don't look like that one you show;
they are usually an "Ice-pick" arrangement with a huge plastic handle that encloses the little test lamp.
If Katie goes out looking for one of what you have in your photo, she will need to hop a plane to the Old-country!!

Jean, I found it hard to believe that the good ol' US of A couldn't supply little 12V test lamps, so I googled "mini 12V test lamp" and turned up one from Walmart and another from Autozone. If you don't have one, you are missing out. The one I have (pic above) is particularly useful. With the screw-on brass cover fitted it will securely wedge between the jug fins when doing the static timing.

AND, the little sharp point is useful for getting that last pickle out of the jar.

Getting back to Katie's problem - yes, I wonder if the carriers let some smoke out when they removed the cowl, and that was the reason for disconnecting the battery. Something that is seriously lacking for most of our old airheads is a decent fuse in the red main power wire that goes to starter relay and headlight.

[Major Softie]

Oh yes, we have them. Jean's point was that they won't look like the classic piece in your photo - more like this (Home Depot):




Or this (Amazon or many automotive stores):

[ME 109]

Oh yes, we have them. Jean's point was that they won't look like the classic piece in your photo

Classic piece?? That's state of the art over here.

[KatieR80ST]

Hey thanks to all! The only power we've been able to trace with a handy little doomajig as suggested here is power to the accessory plug (by the luggage rack on the right) and, strangely enough, to the clock. The bike is dead as a doornail (if in fact doornails are dead--that is open to discussion). There are no lights of any kind--no generator light, no headlight, no signs of life of any kind. I have jiggled the kill switch to no avail. Best guess is that it's a wire to the ignition switch but that was far easier to disconnect than to reconnect. And--I agree that it was beyond stupid to take off the cowling, but I wasn't there...