John Vine Posted January 5, 2020 Share Posted January 5, 2020 Sounds more and more like either (a) a faulty dip switch or (b) faulty or detached wiring between relay and dip switch.JV Link to comment Share on other sites More sharing options...
Toby S Posted January 5, 2020 Share Posted January 5, 2020 My 1992 1400 Supersport had the same problem you mentioned in #1 a few years ago and it turned out to be the switch - your switch looks pretty similar from a dashboard view.I popped the switch out and disconnected the white wire plastic holder at back - then dismantled the switch (levered the tabs at side with a flat blade screwdriver and then pulled apart) and it was crud (green oxidisation) on the metal copper strip - cleaned up and put switch back together and refitted and hey presto everything worked - 10 min job - switch is a very simple affair just a copper strip, slider and copper contact points Link to comment Share on other sites More sharing options...
Jonathan Kay Posted January 5, 2020 Share Posted January 5, 2020 (a) a faulty dip switchI interpreted the voltage readouts as showing no feed to the main/dip switch. Happy to be wrong again if it speeds the solution.Jonathan Link to comment Share on other sites More sharing options...
John Vine Posted January 5, 2020 Share Posted January 5, 2020 Re #28:Yes, just looked at the table again and you're right, Jonathan. I'll stick with (b) if it includes the relay itself! JV Link to comment Share on other sites More sharing options...
goodcoffeecode Posted January 5, 2020 Author Share Posted January 5, 2020 Thanks John and Jonathan. Do you happen to know which of the 3 pins on the dip switch should be receiving the voltage (top, middle or bottom)? Link to comment Share on other sites More sharing options...
Jonathan Kay Posted January 5, 2020 Share Posted January 5, 2020 No, but you can work it out by either:Identifying the colours of the wires connected to each terminal, orLABELLING THE CURRENT CONNECTIONS CAREFULLY then disconnecting everything, switching your multimeter to resistance or continuity and testing which terminals are connected to each other as you select the switch positions. The terminal that's always connected to one or other of the others is the input terminal.JonathanPS: Thanks, John.PPS: I rotated my switch 180° from the way it came from the factory. Seemed more natural. Link to comment Share on other sites More sharing options...
EEK Posted January 6, 2020 Share Posted January 6, 2020 I suspect you will find the issue is in the three way switch, as the third position is only supplying a low current to the relay then any resistance on those contacts will easily kill current flow. Link to comment Share on other sites More sharing options...
goodcoffeecode Posted January 6, 2020 Author Share Posted January 6, 2020 Hi Eek,The 3-way main switch measures ~12.5v on all pins when in position 3. Is that not expected? I understand the idea that low current might get stopped by resistance, but none of those are low are they? Link to comment Share on other sites More sharing options...
goodcoffeecode Posted January 6, 2020 Author Share Posted January 6, 2020 SUCCESS!!! It was the relay.I switched 2 identical relays and the lights worked as expected. Switched them back again (to rule out a random seating issue) and they failed again.Thank you all SOOOOO much for all your help. I've learnt a ton of stuff and had fun doing it. I think if this had happened on my old 911, I'd be bricking it!Where's the best place to source new relays? Is this the correct replacement? Link to comment Share on other sites More sharing options...
SM25T Posted January 6, 2020 Share Posted January 6, 2020 Call Chris at Redline Components 01883 346515. He can post the right one at the best price. Link to comment Share on other sites More sharing options...
John Vine Posted January 6, 2020 Share Posted January 6, 2020 Well done! A good bit of detective work.Do you happen to know which of the 3 pins on the dip switch should be receiving the voltage (top, middle or bottom)?For the benefit of others who may happen across this thread, it's the middle one. These are the connections:Main beam - blue/white (UW) 12v supply - blue (U) Dipped beam - blue/red (UR)This switch is in the "dipped" position.JV Link to comment Share on other sites More sharing options...
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