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Discussion Starter · #1 ·
For a while I have wanted to add a facility for hazard flashers to my Bonneville SE. I have read a couple of threads on this forum about the subject but not found anything which works like hazards should. I have therefore devised my own add-on system, which although is more involved to do compared to those on other threads, is a proper full hazard system and like the others can be applied to any vehicle.

The hazards will work with the ignition off. Some people may not like the idea of this too much, but I for one wouldn't like to be stranded in an awkward situation, in heavy traffic, where I had to leave the bike to fetch help with the keys in it. My car's hazard flashers work without the keys in and so should those on my bike. However, if you are not comfortable doing this you can always wire the hazard switch to a switched supply (more on this later).

Here is my circuit diagram:



How it works:

Firstly I got one of these...

http://compare.ebay.co.uk/like/260986287640?var=lv&ltyp=AllFixedPriceItemTypes&va r=sbar&adtype=pla

The hazard switch supplies power to a SPCO (single pole change over) relay, energising it and switching in the diodes, and at the same time switching out the turn signal switch and supplying power to the flasher unit. The relay is from Maplin Electronics and cost £2.29, order code N00AW.

The diodes need to be heavy enough to handle the current drawn by all 4 indicators (21Wx4+2.6W = 86.6W. 86.6W/12V = 7.2A). P600A diodes rated at 6A are more than adequate since each diode in the pair feeds 2 lamps and collectively will handle 12A. I used 4 x P600A diodes for the relays and 2 x 1N4007 diodes to modify the idiot light. For clarity the modification to the idiot light is not shown (except on the schematic diagram). This is discussed in another thread:

http://www.triumphrat.net/twins-technical-talk/162303-led-turn-signals.html#post1776477

The diode D1 in the diagram has been spliced into the orange/green wire which comes from fuse 7 in the fuse box and goes originally to the flasher relay. This diode prevents other wiring becoming live when power is applied to the flasher unit from the hazard switch while the ignition is off, since fuses 7,8 and 9 are all linked together in the fuse box and are supplied by the blue/yellow wire from the ignition switch. Similarly the other diode of the pair, D2, prevents the SPCO relay from activating via fuse 7 when the ignition is on.

In order to work with ignition off, the hazard switch needs an unswitched supply. Since I have no accessories and do not plan any, I have used the wiring for the accessory socket, which normally just hangs disconnected under the tank with no insulation - even though it is permanently live. Nice one Triumph. This wiring goes back to fuse 3 in the fuse box (10A). I made the connection to that by insulating the crimp part of a male Lucar connector with heat shrink tubing and just plugging it into the accessory connector block. The whole thing was then wrapped in insulating tape.

Note - If you only want the hazards to work with the ignition on, connect the hazard switch to the orange/green wire instead of the accessory power connector.

Most of the wiring is done between the two relays, so I found the most convenient way, and to avoid cutting the wiring harness wherever possible, was to mount the SPCO relay in place of the Flasher relay, then the Flasher relay was mounted to the frame under the seat with a sticky pad. This way only 2 wires in the rear fender harness need to be cut. The original wiring, which would normally go to the Flasher relay now goes to the SPCO relay. Here is a simpler diagram which shows the actual wiring:



To avoid cutting the Flasher relay wiring, the wires are removed from the flasher relay socket. If you unplug the flasher relay and look at the socket you will see a small square hole by each of the 'slots' that the relay blades go into. By inserting a small screwdriver into this hole by each connector and releasing the barb on the connector the wire will pull out from the back. The connectors are then insulated with a piece of heat shrink tubing.



There are originally 3 wires running to the Flasher Relay, these are (including the connection numbers):

Orange/Green - Power (49)
Green/Brown - Turn Switch (49a)
Black - Ground (31)

The added wiring can have any colours you like, I used a length of trailer cable with the outer cover stripped off, which was just the right wire gauge that I wanted, and there were 7 colours. Connectors used were brass crimp Lucar 'spade' type with rubber covers. A dab of solder was applied to each after crimping to ensure a good lasting connection, though this is not essential.

The SPCO relay fitted to the bike.



The new position of the Flasher relay.



All working.

 

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Discussion Starter · #5 ·
Fantastic post, thanks. Top class content and presentation :)
Thank you Forchetto. You know what they say, that imitation is the sincerest form of flattery. I have learned such a lot from studying your posts and my photos show the Forchetto influence :)
 
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