Author Topic: Low voltage from start button  (Read 4571 times)

Offline Doodaadog

  • Motobrick Curious
  • Posts: 26
Low voltage from start button
« on: June 22, 2018, 09:59:25 AM »
Helppp....hello fellow Bricksters.....almost at the end of my recommissioning of a 92 K1100 LT...
It had been stood for 9 years...yup 9 years.
Have managed to get it running and MOT’d after many a trial and tribulation.

But....it has developed a fault at the start button....I’m only getting 6v (ish) through.....managed to bypass it and rigged up a temporary start button....which throws 12v (fused) direct from battery........but would love to fix it.

Things I’ve tried...
Dismantled handle bar switch, cleaned contacts, checked spring etc. I do get a continuity when I put my meter across the terminals....when I check Volts I am only getting 6v.....?

Checked for loose or corroded terminals / connectors

Checked for chafing / mouse nibbles etc.....

All test OK

Any help appreciated

Regards Greg
  • Lincoln, England
  • K1100LT 92
Ducati Monster 1200s
Montesa 315R
BMW K1100 LT

Offline The Mighty Gryphon

  • Administrator
  • ^ Quintessential Motobricker
  • Posts: 6843
Re: Low voltage from start button
« Reply #1 on: June 22, 2018, 10:51:20 AM »
You have cleaned the pushbutton contacts inside the switch with Deoxit, haven't you? 

Are you getting 12v to the start button contacts?
  • In my garage in Marilla, NY
  • '91K100RS White/Blue
Current:
'91 K100RS16V "Moby Brick Too"

Past:
'94 K75RT "Ilsa, She Wolf of the SS"
'92 K100RS16V "Moby Brick" (RIP, deceased in a vehicular assault)
'94 K75S Special Edition Dakar Yellow "Cheetos"
'89 K100RS Special Edition "Special Ed"

Offline Doodaadog

  • Motobrick Curious
  • Posts: 26
Re: Low voltage from start button
« Reply #2 on: June 22, 2018, 02:55:13 PM »
Haven’t tried deoxit not seen it here in UK, have ‘scratched’ contacts, I’m hoping that it will be as easy as the contacts....
Thanks for taking time to reply...
Regards Greg
  • Lincoln, England
  • K1100LT 92
Ducati Monster 1200s
Montesa 315R
BMW K1100 LT

Offline Laitch

  • Faster than a speeding pullet
  • Administrator
  • ^ Quintessential Motobricker
  • Posts: 11299
Re: Low voltage from start button
« Reply #3 on: June 22, 2018, 03:09:38 PM »
Haven’t tried deoxit not seen it here in UK . . .
It's there somewhere, apparently. Your ignition switch might need cleaning also. Instructions are on the site. Check the incoming voltage to the switch as Gryph has indicated.
  • Along the Ridley in Vermont.
  • 1995 K75 89,000 miles

Offline Martin

  • ^ Quintessential Motobricker
  • Posts: 4475
Re: Low voltage from start button
« Reply #4 on: June 22, 2018, 03:33:07 PM »
Try Jaycar UK for the DeoxIT. It now comes as a two part spray first one cleans, the second one gives it a coating to aid conductivity.
Regards Martin.
  • North Lakes Queensland Australia
  • 1992 K75s Hybrid, Lefaux, Vespa V twin.

Offline Inge K.

  • ^ Quintessential Motobricker
  • Posts: 1451
Re: Low voltage from start button
« Reply #5 on: June 22, 2018, 04:00:26 PM »
Check the voltage at the black/green wire on the multi connector for the RHS switch assy which you find
under the fuel tank.
Measure on both sides of the multi connector while pressing the start knob, and then pull the clutch and
see if that makes any difference.
  • Norway

Offline stokester

  • ^ SuperNatural Motobricker
  • Posts: 847
Re: Low voltage from start button
« Reply #6 on: June 22, 2018, 07:03:46 PM »
Check the voltage at the black/green wire on the multi connector for the RHS switch assy which you find
under the fuel tank.
Measure on both sides of the multi connector while pressing the start knob, and then pull the clutch and
see if that makes any difference.
As Inge mentions, check for voltage under load. 

A meter will show the proper voltage with corrosion on terminals and with all but one strand broken until put under a load.
  • Yorktown Virginia
  • '94 K75S Dakar Yellow - '93 K75S Seiden Blau - '91 R100RT Bermuda Blue- '78 R100S Smoke Red

Offline Doodaadog

  • Motobrick Curious
  • Posts: 26
Re: Low voltage from start button
« Reply #7 on: June 24, 2018, 05:04:21 AM »
Thank you for your ideas...will try them out and report back
  • Lincoln, England
  • K1100LT 92
Ducati Monster 1200s
Montesa 315R
BMW K1100 LT

Offline DEcosse

  • Motobrick Curious
  • Posts: 28
Re: Low voltage from start button
« Reply #8 on: June 26, 2018, 01:50:15 AM »
....  pull the clutch and
see if that makes any difference.

This part is a key component in identifying where the fault lies:
The 'start enable' (which is the INPUT to the Start Switch) has two possible sources;
EITHER the Transmission is in Neutral OR you have the clutch pulled.

So ....
Pulling clutch makes no difference - problem would be in the start switch itself, oxidation/pitting of the contacts
Pulling Clutch DOES make a difference - problem would be in the Lunch Box
  • CA, USA
  • Triumph Daytona 955

Tags: