...after considering my post re LEDs - it struck me - does the NC35 need a relay for 55/60 bulbs?

It doesn't have an on/off switch for the lights - they are always on - so it can't bork the switch gear. The only wiring through the switch gear is for the main beam, and that goes via a relay anyways....

OEM NC30/35 headlight wiring configurations can vary significantly if the available diagrams and specifications are anything to go by. Haynes states that UK headlight bulbs are 55/60 without identifying which models and Jap imports are 35/60. Haynes wiring diagrams have hi/lo beam relays for UK NC30, and only hi relay for NC35. I have wiring diagrams for NC30 that have hi/lo beam relays and only hi beam relay, yet both had 55/60 bulbs.

Your comment regard NC35 wiring for lo beam is correct, although passing 2 x 55W load through the handle bar mounted START switch may not be any more reliable than 2 x 55W load through an NC30 lo beam switch without a relay. The START switches have been known to go faulty.

Better solution is relays to make the switching remote and best solution is individual hi/lo power feeds directly from the battery to the headlights via relays.

magg wrote:OEM NC30/35 headlight wiring configurations can vary significantly if the available diagrams and specifications are anything to go by. Haynes states that UK headlight bulbs are 55/60 without identifying which models and Jap imports are 35/60. Haynes wiring diagrams have hi/lo beam relays for UK NC30, and only hi relay for NC35. I have wiring diagrams for NC30 that have hi/lo beam relays and only hi beam relay, yet both had 55/60 bulbs.

Your comment regard NC35 wiring for lo beam is correct, although passing 2 x 55W load through the handle bar mounted START switch may not be any more reliable than 2 x 55W load through an NC30 lo beam switch without a relay. The START switches have been known to go faulty.

Better solution is relays to make the switching remote and best solution is individual hi/lo power feeds directly from the battery to the headlights via relays.

Where are you getting this information from?

The Japanese spec NC30s as per the Japanese service manual and final revision parts manual all have H4R 60/35 watt bulb and has no low beam realy.

There are UK / German / French and possibly other builds of NC30, the UK bike at least has 60/55 H4 bulbs and low beam relay as well.

I don't have any UK or Europe spec parts manuals / service books or wiring diagrams to confirm what bulbs are in those, the German one or it could be French one does have large headlights...

but, if they put a relay in the UK one becuase of the H4 bulbs I can't see any bike being made without the relay that has H4 as stock due to the melting switchgear.

As for the NC35 which is Japanese only, use the search button and look at relay mod, you willl see some nc35 owners talking about it as they have had trouble as magg has identified with melting start swithces.

Drawing numbered 0030Z-MR8-6100 in the 1990 issue of the Honda VFR400 service manual has 2 x 55/60W bulbs and only a hi beam relay. This drawing is not referenced to any particular model. Honda could have made changes during production to a hi/low relay version as a result of reliability issues with the original single relay design.

I don't think Honda made any such change, I've worked on launch year UK nc30 models which have high and low beam relays as stock, to my knowledge all UK bikes have this (as per the diagram in the service manual you mentioned, the first one though not the second.)

The diagram you refer to is for the the French and German models of NC30, they are the ones with the giant headlights. (F/G models)

I think they also have 60/55 watt stock H4's but ive never worked on one. It could be something as simple as a printing error in the service book, if the quality of translation is anythign to go by it wouldn't surprise me at all if its a mistake.

The bikes were lanuched in all 3 teretories around the same time, France, Germany and UK.. since Honda already knew it needed a relay on the low beam of the uk bike it seems pretty inconceivable that they would forsake it on German and French models (which also got folding mirrors and a different oil cooler if i remember correctly) unless they had upgraded swithc gear

We need a guy on here with a French or German bike to confirm the precence of absence of a low beam relay.

Both French and German NC30s had the large headlights, though not the Austrian ones!

However, they may have not illuminated both bulbs on low-beam (like most other Continental twin-headlight bikes of the '90s), and if not, may not have needed a low beam relay.

LOL, CMS has the French, German and Austrian microfiche:



(Anyone want a brand new big-beam top fairing?)



The relay quantities specified in the CMS microfiche say that the UK and Austrian bikes each had two, as well as 55/60w H4 bulbs (and two position lights). The French and German bikes each had one relay, two 55/60w H4 bulbs (the French ones being yellow) and one position light. I think the single position light and single relay suggests that only one of the lamps on the F/G bikes was illuminated on low beam.

Ciao,

I added the relay wiring yesterday for my NC35.

Previously the voltage at the headlights was around 10v - a 4.6V drop through the wiring loom (implies about 4Ohm impedance in the loom to the lights). With the new wiring (2core [using both cores] 8A cable) I am getting 14.2V at the lights - as opposed to 14.6V at the battery - giving me an impedance of 0.04Ohm - which is much better!

I didn't look at the wiring diagrams on here for the mod - but here is what I did...

Got a 25A relay and snipped the wires to the dipped beam. One of these I taped up and the other I used to drive the relay. Ran the wiring from the battery (via a 15A inline fuse) to the relay - and then the switched side of it, I ran a piece of 8A cable to the bulb side of the wire that I snipped.

Tidied it all up and cable tied the new relay to the side of the main-beam relay.


Only cause for concern that I had was that during the testing of this, I had flattened my battery - I guess the lights must have been on for 40mins or so...

When I had completed it all I had to jump start the bike from my car. When I took it for a spin last night the battery was only getting 13V - and I was fretting that I'd borked the battery/reg-rec/generator during the jump start.

Left the bike on trickle charge over night - and tried again this morning, and all is back to normal - 14.6V at the battery when revs are > 5000rpm.

All is well in the world again! And my lights are *much* brighter!

Oh - also - a quick check on the bulbs that were in my NC35 - it already had 55/60 bulbs in. I guess the previous owner didn't want to fork out the £££ for the 30W bulbs - luckily no damage has been done.

Here's a thought though - will the headlight casing cope with the heat of the these bulbs?

JZH wrote:Both French and German NC30s had the large headlights, though not the Austrian ones!

However, they may have not illuminated both bulbs on low-beam (like most other Continental twin-headlight bikes of the '90s), and if not, may not have needed a low beam relay.

LOL, CMS has the French, German and Austrian microfiche:



(Anyone want a brand new big-beam top fairing?)



The relay quantities specified in the CMS microfiche say that the UK and Austrian bikes each had two, as well as 55/60w H4 bulbs (and two position lights). The French and German bikes each had one relay, two 55/60w H4 bulbs (the French ones being yellow) and one position light. I think the single position light and single relay suggests that only one of the lamps on the F/G bikes was illuminated on low beam.

Ciao,

Nice detective work.

I totally forgot about the EU bikes using one light on low beam :)

i know they are stock h4 lamps as its outlined in the service book.

Since they all came out the same time and Honda knew they needed a relay for twin bulbs i think you are right, i tried finding a France / German NC30 owner to ask but had no luck, surely somebody on here can find one to confirm!

maybe youtube...

Purpose of my comment was that the OEM design may not always be the best from an engineering perspective. Cost and production efficiency can be very strong driving factors in the design and an alternative approach may be a better engineering solution.