Electric fault

[Greg65]

I have a GS 1000 1978 UK bike. When I first brought the bike it was fitted with small after market cheap indicators. Having sourced a set of originals I fitted them last week. Checked the earthing which had been adapted by me to a single point earth and all was good. So powered up and got a few flashes on one side and then nothing. Main and Head light fuse blown!

So have spent the last few days trying to work out what is going on. First fault I found was the fuse box had been filled, I guess to avoid corrosion but this had retained moisture and copper had leached into and shorted the system. Unpicked all the sealant and proceeded to then check continuity of various circuits. Have discovered that the feed to the indicator relay had been cut from the original feed and spliced into the Head light feed! The general poor state of the wiring Leeds me to wonder why this had been done?

The question I have at this stage is this. I have removed all the fuses, battery and ignition is off, when I use the multi-meter and touch the indicator fuse holder and single point earth I get a circuit. If I then disconnect the 9 pin plug that feeds the tachometer/speedometer the circuit is broken. Is this normal? If so I will just correct the feed error.

Comments, advice and suggestions as always appreciated.

Greg

[Nessism]

Not sure if this is related but the pre-1980 turn signal control units were garbage and failed often. I've not heard about them causing fuses to fail before but who knows?

[Big T]

Ed, in 78, only the E model had the notorious TSCU.
But, I think all the UK bikes are E models

Greg, you have a wiring diagram for the bike?

[Brendan W]

Assuming there was some logic in the POs actions, , why would you splice a feed into another circuit?
Because there was no power on the signal supply and there was on the headlight?
Then rather than address the signal, possible fusebox problem, they took a shortcut and loaded up the headlight fuse with the signal load as well?
Maybe the small signals worked because they were lower load and when you put back original type the fuse blows?
Unfortunately, when starting from an unknown baseline I don't see much option other than tracing every wire from the main fuse to the ign switch, back to the fusebox and so on. If you get lucky that systematic approach could turn up a find in an unexpected place sooner rather than later.
If you don't have it already the service manual for the E is here

http://members.dslextreme.com/users/bikecliff/

[Rijko]

I have a GS 1000 1978 UK bike.

The question I have at this stage is this. I have removed all the fuses, battery and ignition is off, when I use the multi-meter and touch the indicator fuse holder and single point earth I get a circuit. If I then disconnect the 9 pin plug that feeds the tachometer/speedometer the circuit is broken. Is this normal? If so I will just correct the feed error.

Comments, advice and suggestions as always appreciated.

Greg

Yes, that is normal : you are getting continuity via the turn signal indicator lamp in the dash.

I don't have a good GS1000 electric scheme handy but check this one for instance, follow the green wire :
gs450wiring.jpg - OneDrive (live.com)

[pdqford]

If it is true what the OP posted, “I have removed ALL the fuses, battery AND ignition is off....”, how is any current getting to the turn signal indicator fuse holder? Is that normal? (But then, I don’t have A UK GS1000 wiring diagram., but am trying to follow along as best I can.)

[Greg65]

Sorry for the slow response my beekeeping hobby in the shape of a swarm has otherwise occupied me.

I should have said indicators were off however I’m wondering if the circuit is being completed via the low oil pressure light since the engine is not running?

Will dig into it in a few days as I have my parents are arriving for a few days and hiding in the workshop is not permitted.

Cheers,
Greg

[Rijko]

If it is true what the OP posted, “I have removed ALL the fuses, battery AND ignition is off....”, how is any current getting to the turn signal indicator fuse holder? Is that normal? (But then, I don’t have A UK GS1000 wiring diagram., but am trying to follow along as best I can.)

You are right, there is no current present the way OP is measuring.
Greg is measuring continuity, not voltage/current.
I was wrong about continuity through the turn signal indicator lamp though.

Sorry for the slow response my beekeeping hobby in the shape of a swarm has otherwise occupied me.
I should have said indicators were off however I’m wondering if the circuit is being completed via the low oil pressure light since the engine is not running?
Will dig into it in a few days as I have my parents are arriving for a few days and hiding in the workshop is not permitted.

Cheers,
Greg

Oil pressure switch, neutral switch, or fuel gauge, i think.

GS1000 wiring diagram.jpg