Topic: Headlight relay?

[jakec]

I have four 1970 bikes (750, 2x 350, ct90) all running modern solid state combination reg/rec units. Today on 4into1.com I saw this review and found it interesting. I'm wondering what bikes this would apply to, he just says "early." Any thoughts on this?

[newday777]

Hondaman sells a headlight relay kit.(I  don't know if 4into1 has decent kit for a recommend)
Relays are a real good idea, (and also one for the horn), They put full battery voltage to them so you get the best light and loudest horn output and a relay saves the switches from being burned out from the full amp draw through the switches.
Look in the for sale section at the top of the page for his store.

[70CB750]

I had VW relay panel in my stash, used two of them to wire the low and high beam.  It's not hard.  I actually done it for my CJ7 before. 

Also relays will protect the aftermarket handlebar switch - it can burn out without it.

[rotortiller]

Roughly 45 years on my stock 77 K7  55 watt stock headlight wiring and it still works fine, but then again it has no handlebar switch. Install a proper LED or HID and you kill 2 birds with one stone, provided you are actually concerned with brightness and/or a reduction in circuit tasking. If I was concerned with battery voltage I would check with a meter headlight on and off at rpm and then make a decision based upon fact. The regulator  on CB750 is adjustable.

[MauiK3]

I am seeing some good LED replacements for H3 H4 and H13 bulbs, I tried some in my Colorado ZR2 and my JL Wrangler. They work well, this could be an answer to current draw and charging concerns.

[Bodi]

They all need some cooling solution, usually a small fan and heat sink. The headlight bucket has extremely limited space and is usually full of wires. Maybe an LED bulb can be made to fit?
As far as I know, none are DOT certified for on-road use and most have a notice on the package OFF ROAD USE ONLY.  You will find "DOT Certified" ones, but all from China and pretty sketchy. It's not unusual for China products to claim UL, CSA, DOT, etc "approval" for obviously unapprovable products.
Many if not all are blinding to oncoming traffic.

[MauiK3]

Yes, the brand I’ve tried says “off road”. That being said, when I changed I marked my pattern on the wall and compared old to new. The only change was improved light and a better defined cutoff. Some brands seem to be doing an ok job. I will be researching for the CB750 next.

[bryanj]

Here in uk there is a maximum legal wattage for headlamp bulbs so that could be your not for road use warning

[HondaMan]

I have four 1970 bikes (750, 2x 350, ct90) all running modern solid state combination reg/rec units. Today on 4into1.com I saw this review and found it interesting. I'm wondering what bikes this would apply to, he just says "early." Any thoughts on this?

This message is key to understanding how to install a solid-state voltage regulator in these bikes. Since the wiring's bullet plugs are, shall we say, less than efficient (being zinc-plated steel until 1971 and zinc-plated mystery metal after that) they tend to lose about 0.1 volt per amp pulled thru that plug. So, the typical headlight is running at [(battery volts) - (8 * 0.1 volt)] = 11.8 volts in a brand-new wiring harness. (Your results WILL vary, and with bigger loss numbers!)

So, when a solid-state Vreg is installed its sensing wire must be connected where the main loads are distributed, i.e., in the headlight bucket. Many folks don't do (or know) this, and the results can be very...warming...for the wiring! If the battery is a lead-acid type (even sealed) this won't hurt it, but if it is an AGM or lithium type there can be significant troubles with overcharging (with 'significant' being a lawyer-chosen word to describe these warnings.).

[rotortiller]

You will find "DOT Certified" ones, but all from China and pretty sketchy. It's not unusual for China products to claim UL, CSA, DOT, etc "approval" for obviously unapprovable products.

Then I'd say we are pretty fortunate to have the LED Asian supply line since you say they are all from China. Without China we would have no alternatives. lol    Most all of the respective vintage electrical stuff such as batteries, ignitions, reproduction signal lights, wire harnesses, regulators bla-bla-bla come from China often marketeered by North Americans driving up prices. I would again say we are pretty lucky when we can find a more direct supply route circumventing skimmers. Locals will not make LED headlights because workers want too much and if you consented to higher wages etc they would simply go on strike and down the road throw a wrench into the works.  Reminds me of the Zappy song "Flakes"

[dave500]

ive run a 60/55 no relay for years no trouble with the switch contacts,i dont ride at night but run the head light daytime,im sure a relay would give a little better brightness at night though?

[Deltarider]

Before installing extra parts like relays, diagnose first. It's sooo easy. Battery should be well charged. Just read the voltage at the headlamp fitting when revved > 3000 and decide. I bet you, you won't need a relay at all.
Then this: brightness isn't a quality in itself. Rallys were also won by cars equipped with yellow headlamps. You will curse that brightness, every time a roadsign blinds you by reflecting your brightness.