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Twin Dominator H4 headlights, dual relays - Questions...

15K views 31 replies 8 participants last post by  Richard-Cranium 
#1 ·
So, I bought myself a set of Dominators for my K3 Bandit 600, to replace the single headlight and because I'd like it to be a lighting upgrade, as well as a cosmetic one, I'm looking at rewiring it with relays.

Most of the diagrams I see show one relay for both low beams and a second for both high beams... why not one 5pin relay per light?
Surely I can use 87a as a source for low beam power and 87 for high, can't I?

Does the Bandit already use a relay for the headlight and if so, would that affect anything?
It's a Euro model, so the lights are on with the ignition.
As far as I know, the main beam switch alternates the supply between the filaments, whereas the Pass button activates both somehow - is this the deciding factor between choosing a 4pin relay per selection as opposed to a 5pin per light? (If need be, I'd just rig that to activate the main beam alone, I guess.)

Where does everyone take their permanent power feed for the relays from? All the way to the battery direct or is there an alternative solution?

Any other concerns to take into account, based on the bike in question?
Oh, just something I noticed the other day - my hazards make my taillight dim as they flash... am I going to be okay with the extra drain of another headlight bulb?
I do have a multimeter here, if that helps...

Cheers in advance for any insight.
I'm sure the answers to the above will lead to further questions and I'll probably draw up & post a wiring diagram to sanity check before going ahead with it.
 
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#2 ·
The taillight dims because its probably on the same ground or power circuit.

Replace the bulbs with led bulbs, and it won't overwork the wiring anymore.
 
#3 ·
Cheers.
I'll probably look at fitting LED indicators to start with, as I've a feeling the Dom shells might foul the OEM front indicators anyway.
I'm aiming to tidy up the tail at some point anyway, so I'll look at LED tail light options then (unless my hand is forced by the headlamp mod).
 
#4 ·


*Bump*

Anyone help me out with the relay q's here?
Was hoping to go buy them & DW today...
 
#5 ·
I would help you if I could just for having Vivian from The Young Ones in you avatar.
 
#6 ·
Hey bud have you looked in here:
http://www.customfighters.com/forums/showthread.php?t=48236

If I were you I would either use 2 DPST relays or 2 SPDT relays. I would probably use the SPDT setup as if a relay fails then at least you have one light left with complete low/hi function.

As for the pass switch, that is something I have yet to investigate and wire into a relay function. If I get time I'll look into it but I'm pretty busy of late... I would *think* that somewhere in the original wiring of it there would be a diode somewhere to prevent the back feeding of voltage through the high beam wire. Also, it's feasible that you would require a relay to run it. You could use a Normally Closed relay on the High circuit or a Normally Open relay on the Low circuit.
I think the best way would be to invetigate how your pass switch works now and get back to us.
Looking at my ex250 healight diagram there isn't even a mention of the pass switch....hopefully yours does...

Re there being enough juice to run an extra light, you need to test it. Rig them up, start your bike and turn them on and get your multimeter on the battery. If she's still putting out at least 13 volts to the battery, you'll be fine. My 250 could run 3 x 50w bulbs just fine so I assume your 600 would be ok...
 
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#7 ·
On further thought, if you wish to retain the "Pass" function, I would use two DPST relays: One for Low. One for High.
If you are just using your original switchgear and not modifying the wiring, and you wire the relays up so that the stock Low/High feeds are the trigger inputs, then the "Pass" function will be retained without the need for another relay.

The way to wire the relays would be to use two DPST relays in the format of the second diagram in the link I posted except terminal 85 on the second relay would got to the stock High feed and terminals 87 would go to the new High beam inputs on the Dominators.

Hope that helps bud.
 
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#8 ·
Thanks man. I'm sure I started reading that post at some point but think it must have got lost in the sea of tabs I had open when I was trying to find the info I needed.

I think you're right that the 'one for low, one for high' approach will be best, simply because of the Pass function. Shame, as I thought the redundancy feature of 'one per light' was a nice touch.


Cheers for the input. Made all the difference. :drinks:
I'll try and update with pics as I do it.
 
#9 ·
Right, update time... pics will be incoming when I find the camera lead.
In the meantime, I have a problem.

Everything worked fine for about a week, then today, I upgraded my bulbs to Osram Night Racers with LED sidelights. These worked fine at first, then when I went out on the bike earlier, I stopped somewhere and when I came back, the headlights were on (tail & sidelights were off and go on & off with the ignition as before).

It seems to be as if one of the relays is stuck open. Is this a common fault?
I've had to disconnect the battery for now but would appreciate any pointers.
 
#11 ·
I run tha same lamps on me ZX9 both highs work at tha same time and both lows work at tha same time offa tha stock relay ,tha lamp are relayed ta be off when runnin tha starter and then on once its runnin .
 
#12 ·
Yeah, I thought about doing the starter cut relay but figured I'd see if I had any problems first.
Didn't till now. :confused:
 
#14 ·
Hope someone knows what's up? :D

Dunno. Might switch the relays and see if the other filaments stay on... in which case, hafta buy another relay, I guess.
Otherwise, mebbe something will jump out at me when I check the wiring.
 
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#16 ·
Yeah, I'm just hoping at least one person who reads it has had the same problem and sussed it.
It's a common enough mod...

I'll bust out the multimeter tomorrow. No light in the lockup to work at night.
 
#17 ·
It's probably a stuck closed relay, either because its faulty or isn't losing the signal that closes it.
 
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#18 ·
Is there an easy way to test for that?
I'm thinking to remove the trigger wire and test for a feed, maybe...
 
#19 ·
Hey bud, what relays have you used?
A common problem is that sometimes the relays are of cheap construction or not rated for the amperage they need.... This results in a burnt out relay or possibly fused relay contacts. It sounds like your relay contacts are fused.
Of course you can try removing the trigger first but I highly doubt that is the problem, unless of course the stock relay is faulty and stuck "on".
If you remove the trigger wire and the lights remain on, you know the relay is faulty....
 
#20 ·
Hey bud, what relays have you used?
A pair of these -



hooked up like this -



If you remove the trigger wire and the lights remain on, you know the relay is faulty....
That's what I figured (and am half expecting).
Course, everywhere's shut tomorrow. :doh:
 
#21 ·
Are those a good brand mate?
So you are only using one output terminal off of each relay?
What wattage are the bulbs you're using?
 
#22 ·
Well, I bought them from my local motor factors, so they shouldn't be too cheap but they ain't Bosch or Hella.

Nope, using both terminals, one per lamp.
(the second pic is a WIP shot btw)

60/55W, same as the ones I took out.
 
#23 ·
WIP shot?

One per lamp? You have H4's so that's 2Lows & 2High's and your relays have 2 outputs each (2 x 87 on each relay)... So you should be running 1 relay for the Lows (so both 87's from 1 relay going to both lamps) and 1 relay for Highs (both 87's going to both lamps).

But even if you are not, each output (87) is rated at 15amps going by the pic you posted and running 2 Lows or 2 Highs off 1 ouput is still under 15amp.... So TECHNICALLY the relay should be able to handle it without burning out or fusing contacts....:confused:
 
#24 ·
WIP = work in progress. I thought you saw the bare terminals in the second pic when you asked about only using one. :D

Yep, I'm running one for both lows and one for highs, like we settled on earlier in the thread.
I figured they should be man enough and I couldn't see any wiring damage when I first looked either.

It'll be light here soon, so I'll go have a play in a bit & see what's occurring.
 
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#25 ·
Well, that's fuggin' weird...
When I left it yesterday, I'd disconnected the main relay ground, so first thing I did was a continuity test between 30 and 87 on both relays - not a peep.
Reconnected the ground and no lights... turned the ignition - on they came; turned it off, they went off.

Bastard fixed itself! :nuts:

Trouble is, I don't trust it now.
I reckon it was a sticking relay. Shop I got it from only had the one brand in stock though & I'm loath to swap like for like. :shootme:
 
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#32 ·
Sounds like you had a dodgey earth there! Relay ground. Earthing problems can cause all sorts of weird things.
 
#28 ·
Nah, only a few quid each.
Paid just under £20 for them with connectors, fresh wire and a couple of inline fuses & holders.

Would have happily paid another tenner for the peace of mind of branded stuff but settled for having them there & then.
Like they say; buy cheap, buy twice. :shootme:
 
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