WHAT RELAY?

[stirlinggaz]

hi all,
this question is for those with a better grasp of electrical knowledge than i have. (which wouldnt be hard,lol)
ok, so i have front indicators wich are 21w each.
& iirc, the rear indicators should be either 3.4w or 5w each.(though i have 4 x 5w indicators & 4 x 21w indicators)
what "size" of relay do i need?
the honda one is a silly price, & not having seen one, i dont know what was written on it.
so i figure if i can get a "generic" (ie cheaper) one, i will be sorted, seeing as i have loads of sets of indicators, wiring, & the switch on the bars.
anyone able to offer any advice, on any set up? (either 2 x21w & 2 x5w or 4 x 21w)
im getting fed up with hand signals & now that is dark most of the time, i think it would be safer to have working indicators.
i have tried a couple of random relays,which i had lying around, but the best i could get, was the front indicators only working. (& the rear would either stay on permanately or not work at all, or the relay would make horrendeous clicking noises).
any one able to help?
cheers,
GAZ
edit : i just looked at the wiring diagram & the mtx 200 should be 4 x 21w & the mtx 125 should have 4 x 10w.
so im presuming that simplfies things?
as i only have 21w & 5w indicators, lol

[finpos]

The front and back indicators should really be the same value, then you can make sense of the markings on the generic flashers. Normally the higher wattage ones go on large bikes where as the lower ones go on ickle bikes. You'll probably never get it to work right with the mix of bulbs you have.

What the marking is telling you is the number of bulbs it's capable of driving. So 2x21W is saying it's designed to operate 2 bulbs (ie, 21W front and 21W back for one side). Sometimes it'll say 2x21W+5W, the 5W is the dash repeater.

If it says something like 4x21W, that'll mean it can flash all 4 lights at once as hazard lights, most of the time this will be a car flasher.

f.

[Blue_SV650S]

Are the rear ones that are currently 5w BA9 fitment? https://www.maplin.co.uk/images/full/n81cf_2.jpg

You can get 21w versions of them - that would be your easiest resolve here ....
____________________
The purpose of life is to fight maturity.

[stirlinggaz]

hi,
the bike didnt come with any indicators (not a legal requirement on a bike this old) or relay fitted, but it does have the wiring & the switch on the bar.
it should have 4 x 21w indicators, which i have managed to source.
i dont have the original relay.
i also have a couple of random relays(not sure of the wattage, as the markings have rubbed off) & some random pairs of indicators, (most of which are 5w).
the bulbs in the oem indicators can be swapped for 5w bulbs, as i have a pack of duracel l r5w bulbs which fit (there the same fitting as the brake/tail light,only difference is they are not the dual filament type), the others im not sure which type of bulbs are in them...
i tested various combinations of indicators & cant get past the front.
i can get the 2 x 21w front working, but as soon as i connect up the rear, it goes pear shaped.(the indicators either stay on, go off all together &/or the relay starts clicking erratically)
i tried both 21w at front & rear.
2 x21w at front & 2x 5w at rear.
5w at front & rear.
this made me think the relays i have, are either knackered or not powerfull enough to power the 4 x 21w..
am i right in thinking, that to power 4 x 21w bulbs, i need at least a relay of at least 84w??
so whats to stop me using a relay from, say a vauxhall astra? (just an example) as these are around 100w? (& can be had for around a fiver, as compared to the 30 quid david silver wants.
cheers,
GAZ

[finpos]

No reason you can't use a car flasher, will usually involve some fiddling to get it wired up, though. I don't think that's your problem;Sounds like you are getting mixed up. You are only powering 2 bulbs at a time from the flasher - front and back for one side. Both of these need to be either 21W or both need to be 5W. Do not mix them. My guess is that all the flashers you have are 2x5W, have you tried 5W bulbs front and back?

[finpos]

...Oh I see you have. Remove the dash repeater bulb - presuming it has one - see if that makes a difference.

[Blue_SV650S]

How have you wired all this up? How many terminals have the relays got? post pics of the relays you have tried to use ...
____________________
The purpose of life is to fight maturity.

[stirlinggaz]

Hi,
yup tried 4 x 5w.
the relays have been both 2 pin & 3 pin.
wiring diagram shows wires connected to relay & 1 wire not connected to anything, wtf?
anyway, stuck to only wiring the 2 pins up, using the colours on the wiring diagram.(that way i only have 50/50 way of getting them the wrong way round)
didnt think about the dash repeater bulb...that blinks away happily when i have the front indicators blinking, but it stays on when i connect up the rear.
i was presuming the relay wasnt powerfull enough, but even when i tried 4 x 5w indies, the same happened.
i will post pics if that helps...but the relays are just square boxes,with terminals +with the markings rubbed off.
i will also describe the wiring that already there.
cheers,
GAZ

[finpos]

clues here:

https://www.vehicle-wiring-products.eu/VWP-onlinestore/relays/flashers.php

Actually, very specific clue, the bike relays they have take 10W bulbs, not 5W. I'd guess your 2x5W flasher is really a 2x10W flasher, which is why it'll run one 21W bulb (do the maths ).

f.

[stirlinggaz]

hi,
thanks.
think i've sussed it.
i was approaching it completely wrong.
i guess i'll get a 2 x 23w (+5w,for the instrument panel) relay.
i'll chuck the relays i have , back in the box of bits.
still cant get over the price of the oem relay, 30 quid , when there are generic ones available for a fiver.
just the wiring to suss out now, lol
cheers,
GAZ

[stirlinggaz]

Hi all,
this is a sort of update.(left it alone for a while)
running an indicator relay with the description "10W x 2 +3.4W"
what size of bulbs should be used, presuming 4 indicators? (10w? presuming that the most amount of lights on at any one time will be 1 x front 10w indy, 1 x 10w rear indy & the instrument panel bulb)
they dont all have to be the same wattage, do they?
what will happen if if i drop the wattage on any of the indicators?
& what about the instrument panel? that has (or is supposed to ) run a 4w bulb.
will removing this bulb have any affect on the indicators?
apologies if im asking the same questions repeatadely, but im still struggliong to get my head round the basics of relays, lol
such as the labelling on the relay "10w x2" is this the maximum the relay can handle?
what happens if i try to run different wattage bulbs? (higher or lower)
cheers,
GAZ

[finpos]

10w bulbs in all 4 indicators, only 2 of which flash at a time, 4w bulb in the dash. your relay should have 3 pins/wires - one 12V, one going to the switch and one going to the dash bulb. Without going into the details, the resistive load of the bulbs, described by the wattage here, is an important part of the timing circuit in the flasher relay. If you use the wrong wattage, the indicators will either stay on, stay off or flash at an odd rate.

[stirlinggaz]

ah, but my relay only has 2 pins.....
though there are 3 wires down there, but the wiring diagram only shows 2 connected to the relay, the other goes nowhere.
cheers,
GAZ

[alun111]

nowhere or to earth?

https://www.labelsourceonline.co.uk/ProdImages/Page004/frl105_g.gif
____________________
Summer: '00 Honda CB600F Hornet
Winter: '93 Suzuki GSF 400 Bandit VP Variable Valve
Past Bikes: Lifan LF100-5 Lifan LF125-A Honda C70

[Ichy]

Just so you know for next time. You can get electronic flasher relays off Ebay for a few quid. Yes they come from China and yes they take a couple of weeks to arrive but they work well and they couldn't care less about wattage. You can mix bulbs or leds. The first one I brought cost £4 with post and is working fine 18 months later.

[finpos]

Conventional wisdom is that a relay that is marked with a rating specifically for the dash repeater also has a connection specifically for it as well. Of course, you can't count on conventional wisdom!

[stirlinggaz]

[Ichy]