tail lights

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49er
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tail lights

#1

Post by 49er » Tue Mar 24, 2009 11:50 am

Hi I want to put turn signals on the rear only, is there a resistor i can put in the line to make the flasher work properly? also how much oil should come out the primary oiler? I have a drop every few seconds.



Cotten
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Re: tail lights

#2

Post by Cotten » Tue Mar 24, 2009 2:26 pm

49er!

The amount of oil that you observe coming out of the oiler snoot can be very deceptive.

It can vary greatly if you watch it immediately starting up a machine that has sat without running for a while. Sumped oil will be purged quickly at first, and the degree of sumping can vary wildly with ballcheck condition, temperature, and duration of downtime.
Even the angle the machine leans on its jiffystand will confuse apparent flow with lags or sudden pukes as oil puddles within the large breather gallery.

So observations should be made basis the spot left on the pavement after the machine has seen typical duty. And the size of the spot can vary also with temperature, oil weight, etc., but normally the spot that forms within a half-hour of parking gives an indication of how much oil was spun up on the walls of the chain case.

Most folks start out with the chain oiler screw on the oilpump shut all the way off, as often there is sufficient blow-by to do the job without any added by the oiler circuit (especially with tired or rad motors).
A machine that sumps typically and is only ridden occasionally will rarely need the screw opened, as the purge will be more than enough to soak the chain for a casual spin. If the pavement dries up after the first pit stop, however, cracking the oiler open would be prudent!


...Cotten
PS: Sorry I have no clue about the electrickal question. I would think that you want more draw through the flasher, rather than to choke it down with a resistor.

es225
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Re: tail lights

#3

Post by es225 » Wed Mar 25, 2009 12:54 pm

A resistor in the line will make thinks worse, as Cotten already suggested. Hide an indicator bulb in your headlamp nacelle and connect it trough two 4 Amp diodes to the two wires that go to both of the rear indicators. The bulb will flash together with any of your rear indicators. That's how I did it.
JW

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Re: tail lights

#4

Post by awander » Wed Mar 25, 2009 3:56 pm

On the other hand, a resistor across each of the rear turn signal bulbs(equal in resistance to the turn signal bulbs) will simulate the missing front turn signal bulbs.

That is going to need to be a large wattage resistor, though, so the bulb and diodes idea is probably the best way.

es225
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Re: tail lights

#5

Post by es225 » Wed Mar 25, 2009 4:01 pm

A resistor is not the best solution, as it has a constant resistance over the whole temperature range. A bulb has a very low resistance when not glowing, and a high resistance when glowing. The flasher is using that bulb's resistance property to work properly.
JW

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Re: tail lights

#6

Post by awander » Wed Mar 25, 2009 4:13 pm

Have you actually tried a rsistor in place of a bulb, with a flasher?

I haven;t, but I believe a resistor equal in resistance to the bulb's "on" resistance would work fine.

The way most flashers work is, while the bulb is on, the current through the flasher causes it to heat up, and a bi-metallic element bends, opening the circuit. This turns the bulb off, and also means no current passes through the flasher. This lets the bi-metallic element cool down, to the point where it bends back, completes the circuit again, and it all repeats.

I can't see how the "OFF resistance of the bulb enters into it, except that it will cause a momentary higher burst of current when the bulb filament is cold. This might heat the element a tiny bit quicker, causing the "ON time of the bulb to be slightly less than the on time of an equivalent resistor.

But I would welcome hearing about actual experience with a resistor.

es225
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Re: tail lights

#7

Post by es225 » Thu Mar 26, 2009 10:07 am

Yes, I tried a resistor, but I couldn't get the flasher work in its desired on-off cycle. It is the very low resistance of a cold bulb that causes a high current shot when the flasher comes in (connect a high-wattage bulb through an ammeter to a battery and watch the needle hit the high side and then backing to the rated bulb current). You can't simulate that with a resistor....
JW

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Re: tail lights

#8

Post by FlatHeadSix » Thu Mar 26, 2009 12:38 pm

Andy,
es225 is correct. Hiding an indicator bulb somewhere is the best solution but don't use a tiny low watt bulb like an actual indicator light, use something like a dome light so that the flasher will cycle more quickly. As JW said you will have to connect your hidden bulb to both the right anf left feeds using diodes if you only want to hide a single bulb.

You can use resistors as long as you wire them in parallel, but the results will not be as good. Its easy enough to experiment, try it both ways and you'll see the difference.

mike

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Re: tail lights

#9

Post by awander » Thu Mar 26, 2009 1:51 pm

It is the very low resistance of a cold bulb that causes a high current shot when the flasher comes in
But, why do you want the high-current shot?

Looks like I will need to get out to the shop and wire it up...

es225
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Re: tail lights

#10

Post by es225 » Thu Mar 26, 2009 3:59 pm

If you opt for the single bulb option and have a six volt system, schottky-diodes are preferable. They have a much lower voltage drop than ordinary diodes. Go for the ultra-low voltage drop 20L15T from International Rectifier. But a dual bulb solution may be cheaper.....
JW

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