TOPIC:

Can anyone let me have a simple wiring diagram for the relay mod to turn the headlight off when starting please?

I have searched but can't find it.

Is there a download section somewhere that it's hiding in?

Many thanks Pete

Hello Pipes66

I made a little drawing for you. I hope it is a little help for your head light power off mod.

Many thanks Scirocco,
2 queries,is it definitely a normally open relay?
Where is the best place to cut the headlight wire?

Regards Peter

Hello Peter

The 5 pin relay do both, opening the circuit on pin 87a and switch to close circuit on pin 87 if you power 12 Volts+ to pin 86 and negative or ground
to pin 85. Your head light bulb connector should have three single bullet connectors to the wiring harness you can Loop in the pin 30 and 87a.
Pin 86 get the 12 Volts from the starter button and pin 85 negative from the black/yellow connector. The relay should fit into the head light housing.

Michael

Be aware, there is also a dual-87 relay that looks the same as the one with the 87A contact.
You don't want the dual-87 version.

The text of the image indicates that the one on the right should be dual-87, which would be a 5-pin relay, but the image only shows a 4-pin relay with a single 87 pin.

The 87A contact is normally closed.
The 87 contact is normally opened.
The dual-87 relay has two normally open contacts instead of one-closed /one-open.
Contact 30 is the common contact .
85 and 86 are for the coil, and can be operated with either polarity.
It makes you wonder where the other 83 or so pins would be?

The 5-pin relay part number 330-070 by Bosch or Tyco usually (if not always) have the 87A contact.
Use socket 330-075 for that relay.

Don't hard-mount it to the frame as strong vibration can activate/deactivate the contacts.

Pipes66 wrote: .... is it definitely a normally open relay? ....

Scirocco is indicating to use the normally closed option on the 87/87A type of 5-pin relay (which has both a normally-open and normally-closed contact).

Before you do anything, make sure you have enough space for your relays inside the headlight bucket. There isn't much space in there, so you might be able to get away with miniature relays, but I couldn't find any that would fit in the bucket of mine.

I ended up using waterproof relays and mounted them just under the tank, and ran the wires up into the headlight bucket.

I've never heard of this mod to switch them off when starting, I installed mine to just improve my headlights.

The advantage of an relay is you can switch a high current device with a low current remote switch.
This protect the switch contact from burning away or melting together.
In Pipes66 case he want to switch off the unnesseseary main head light automaticly , (he can´t switch off manually), to get more battery current
for the e-start motor and ignition to start the bike .

Pipes66, I did this to my 750 Twin model that is notorious for eating batteries. Before installing relay I was replacing conventional battery every 2 years. I have 4 + years on the current one and it is still working fine.
No cutting of wires necessary if you make some pigtails that plug into the factory bullet plugs.
Attached is what worked for me.

Good luck,
Jim

Thanks for the answers guys.
Sorry I havnt been on in a while but the good news is the bike is starting loads better. I’ve taken over looking after this bike for a girl in the club. It turned out her starter motor was absolutely shagged,the brushes were down to the springs,god knows how it was working. It was also full of thick carbon sludge,a seal must have been gone on it. So I got a good used one,fitted a new starter clutch instead of another repair kit and did the relay mod for the coil. I decided not to do the headlight relay mod as it was starting better and thought it’d be better to possibly fit new switchgear with a light switch on it. Also got her to buy a quality new battery.
I’ve been adjusting the mixture screws little by little and it seems pretty good.
I was going to put some new rings in this winter but I’m not sure if it needs it. I’ll have to check the compression again but iirc it was ok.
I changed the base and head gasket and had the head skimmed,new valve stem seals,shimmed it after lapping the valves. I checked the rings in the honed bore and I could get a 0.5 feeler in,the limit is 0.7. There’s no sign of oil coking up the cylinders but I have been suspecting an extra bit of compression would help starting.
Unfortunately the cam cover gasket has started weeping again,no other oil leaks but the gear change seal is making up for it!!
Another reason to be cheerful,she’s won the most mileage prize in the club this year which she tried for last year
Tbh I’ve got so much other stuff to do with my race bike I wish I hadn’t mentioned doing the rings,fz750,20 valve head which after doing the shims,cams out 3 times!!,I’ve found compression down on 3&4 so it’s all got to come out again and get the head off.
Anyway,I’d welcome your thoughts,all the best,Pete