How to Wire a Light Bar Relay (and not drain your battery)

[The Vol-can]

Electrics are giving me headaches. Added new light bar and brake light modulator to my 2005 800 classic. Light bar is on its own 30-amp circuit with a separate relay fed with the ignition switch. Had some light issues which I thought I fixed by re-organizing the relay connections. BUT now am on my second battery and in the space of three days the new one has gone flat - won't even light up my circuit tester across the posts. Will open up the headlight tomorrow to see if that wiring is the problem. This is no fun.

[anamosity]

sorry penguin. Electrical is not my forte. Good luck on finding the problem.

[GREENISBEST]

Hi,
Can you discribe exactly how you have wired up the light bar circuit with bulb wattages and all connections esp your relay cons

Ta

[zedx11]

one sure way to tell if your new wiring is the drain on the battery is to disconnect it. that would either eliminate or confirm if that is the problem.

[The Vol-can]

OK. The light bar is fed from its own circuit independent of that used for the headlight and turn signals, per the recommendation of Wolf and others. I'll try to explain the setup by following the flow of current starting at the battery.

The positive terminal of the battery leads through a 30-amp in-line fuse to the 30-amp relay (post 85). Post 86 leads directly to the negative terminal of the battery. The switch on the relay (post 30) is fed directly from the ignition switch. The lone wire from the light bar is connected to the relay on one of two posts marked 87. The lone wire then leads to the front of the bike where it feeds into one side of the on-off switch located on the light bar itself. The other lead of this switch is connected to the single leads coming from the two lights on the light bar. Since there is not a second wire coming from the lights on the light bar I am assuming them to be grounded to the frame. The turn signals are wired together at the headlight with the negative leads (black/yellow wire) connected to each other and the gray wire is connected with its blue or green counterpart.

Have checked continuity throughout the setup and it all checks out. Used circuit tester to test relay with ignition switch both on and off and it checks out. New battery was picked up already charged last Tuesday. Have had two minor runs on the bike since then. Unplugged battery from bike last night because it seemed so drained of energy. Reconnected it today and all I could get when attempting to start the bike the first time was some rattling in the starter relay. Engine would not turn over. Lost even that much activity in the starter relay very shortly thereafter.

Question: Does the 30-amp relay used in the light bar circuit have to be connected to both the positive and negative post of the battery? Would removing the connection to the negative battery post and grounding it to the frame make any difference?

Question 2: why do I have to switch the turn signal positive leads in order to get the proper turn signal sequence for each turn signal light?

Also added a Back-Off brake light modulator to the electrical system. Negative lead connects to the negative post of the battery, the red lead connects to power coming from the wiring harness, and the white-red lead connects with the wire coming from the taillight that lights the brake lights.

When fully connnected, there are two leads arising from the positive battery terminal (wiring harness and light bar circuit) and three leads connected to the negative terminal (wiring harness, light bar and tail light modulator).

Sorry for such a long post. Wanted to be sure I explained the wiring situaitn in enough detail for you to get a handle on what I face. Should you need more information, just ask and I will get back with you as soon as I can. Any help would be most appreciated, as the outdoor weather is getting really nice...

[GREENISBEST]

Ok lets run through the relay wiring for your circuit as i see it should be..

1) Battery Positive feed to 30amp fuse connect to terminal 30 on relay.

2) Light bar feed wire connect to terminal 87 on relay.

3) Battery earth connect to terminal 85 on relay.

4) Switched live connect to terminal 86 on relay.

Switched live circuit as follows :-

Run a wire from your Battery to the switch your using to switch on your light bar lights.
Fit an inline fuse between the battery positive and the switch for safety and as it's only switching the relay coil a 10amp should be ok.
The wire from the other side of the switch is the switched live connection 86 as above in (4)

Instead of running the wire from the battery you can pick this feed from your Ignition switch without any problems as this will kill the lights when the Ignition is switched off which is why you probably wired it like that to start with

The light modulator circuit i am unsure about as i have not yet fitted one.
They don't seem to have taken off here in England yet, Pity because they look like a good idea

[The Vol-can]

You have done an excellent job of describing the connections that it has taken me the better part of 10 days to figure out through lots of questions and consultations with experts like yourself. I found that I had originally wired the relay so that the two battery terminals were attached to posts 85 and 86. This arrangement kept the coil constantly activated even with the ignition and the lights off. The result was a very dead but very new battery within a matter of days. Have now wired the relay as you indicated, and bike, lights and owner are doing very well, thank you.

Hopefully the forum managers will see this thread and keep it posted as a sticky because it sure was hard for me to interpret the wiring diagram for the relay, and I've had some experience with electronics. Your description makes it crystal clear and should save lots of folks from having to experience my recent aggravation.

BTW, the brake light modulator unit is produced by Back Off! and works like a charm. Really simple to install, too, as even I could do it and get it right...

[Bigguy2x]

Don't know if this will help .... but scroll down to the wiring diagram

http://www.valueaccessories.net/Ligh...r%20Wiring.htm

[GREENISBEST]

Hey the Picture is a great addition to the thread, Some people find it alot easier to follow

Nice one Bigguy2x