The Hodaka Club Forum

I just fired up a new restoration on a Model 94 Wombat and within seconds blew all 4 bulbs, headlight, taillight, instrument bulbs. Common problem with this model, but it happened so fast I didn't even have time to shut it down.

I have a Road Toad 6 volt regulator with the single green wire and the short white ground. I searched some old posts on which wire to tap this into and find both the green and brown wires coming up from the stator mentioned. Tap into this wire before the plastic wiring harness connector? Into the green or brown? I don't want to pop my only remaining headlight.

I just researched this issue when adding lights to a combat wombat .
I did not see a brown wire coming from the stator wiring but there is a brown wire in the main wiring harness that provides voltage to the headlamp through the dimmer switch and ac/dc switch on the headlamp bucket. The brown wire also provides voltage to the tail lamp and instrument bulbs. The green wire from the ignition switch provides voltage to the ac/dc switch which ultimately provides a/c voltage to those lamps.

You would connect the voltage regulator green wire to the green wire coming from the ignition switch. The white wire from the regulator goes to ground of course.

Danny
Edited my post as per Roger's input

Forgot to mention where to install it in the circuit. Any where in the green wire circuit after the ignition switch and before the ac/dc switch connection. Basically you will be cutting the green switch wire and connecting the two ends to the green wire double bullet connector from the voltage regulator.

Danny
Edited my post as per Roger's input

I modified the Wombat Wiring Diagram for those who want to incorporate a VR. You can find it here: http://www.strictlyhodaka.com/v/vspfile ... iagram.jpg


One thing to keep in mind is that for a Model 94/94A,there are two green wire circuits. The green wire from the magneto is AC current for Day operation. This green wire passes through terminals C1 to SE and then the rectifier, and powers the stop, horn, and speedo lights, and also charges the battery. When the key is placed in the Night position, C1 terminal is opened and now the AC current comes from the Yellow wire from the magneto which closes terminals C2 SE and HL. The C2 to SE terminal powers the same lights mention above and C2 to HL terminal powers the rest. It is the Green wire from the key switch that must be regulated. If you don't have a key switch, it's a different story.

I used a piece of slim angle iron to mount the VR to the bottom of my battery tray. I used the existing current limiter mounts to mount it. Then I ran the green wire up under the seat where it ties in to the green wire from the key switch and main harness. If it hasn't been modified, it will be a single male to single female connection. I used a double female on the VR and made sure the other two were single male connectors.

You can place the VR anywhere you like, just make sure it's grounded and attached anywhere in the AC circuit, (Green wire from the key switch).

$0.02

Roger

Roger,
Re-checked the wiring diagram again and you are correct. Green wire from switch on a md 94. Edited my post for clarity.

Danny

From the discussion, and looking at the parts list for the 94, the 94 didn't come with a regulator. Also pointed out is the problem of popping bulbs.

My question is this: has anyone measured the voltage output of the lighting coils on the 94? I am curious to know what the unregulated voltage is. Most bulbs will tolerate more voltage than their rating. If popping bulbs has been an issue all along, I assume the coils put out substantially more than the odd 8 volts referenced in the specs.

GMC,
The model 94 did not have a voltage regulator for the headlamp circuit but the model 94a added a current limiter. My understanding is the current limiter was added to address bulb life issues. Later model Hodaka's replaced the current limiter with a voltage regulator.

I have no results on lighting coil voltage...so no help there. I would "suspect" at rpm the voltage may be higher than listed. I did attempt to measure voltage on the lighting coil I wired into the combat wombat with out success. With out a load on the circuit my digital volt meter would not register a reading......ac or dc. May be a load needed to be applied, analog meter used ?????? I did not have a lot of time to research this further so that is where I ended up at.

Danny

I am wondering just how close the 94 system comes to being a 12 v system, thinking that with modification of the coil windings, we might be able to bring the Hodaka into the 21st century, using high output, low draw 12v lighting available now that wasn't available then.

My 1975 RD350B came with a 35W/35W headlight. It was thought to be sufficient then, but today, it is like using a Boy Scout flashlight as a headlight. I upgraded to a 1000 plus lumen LED lamp that draws only 33W. Night and day difference, pun intended.

Perhaps if we could baseline the potential of the existing 94 lighting system, we would know how close it already is to being 12v capable, which could lead to modern lighting on our vintage bikes.

Danny,

Not expert in this, but I think you need to put the meter in line with the volt source to read output. Generally, we just piggyback on top of the load leads, but without a load, the meter has to take the place of the load. Either way, a voltage signal has to be readable, analog or digital.

GMC,

You may be right. I just had to complete the bike so Will could go racing.
Next project maybe a little more time can be spent on researching this.

Danny

Or anyone out there with a 94, or even the later models if a reading is taken before the regulator. I am thinking that the coils are the same between models, and were not made by Hodaka. The coils might have been stronger than spec, which might not have been tested for prior to production, but fixed after the fact instead by inserting a limiter.

If so, the 94 might already be putting out upwards of 12v, or might be caused to do so by rewinding them. The book says "over 6v at 2,500 rpm and under 9v at 8,000 rpm." But, one would expect that if this were so, they would not have had a problem with bulbs, and would not have needed a regulator. Rather than retool the coils, or source different coils, Hodaka chose to add a regulator which was not expensive, and which probably should have been part of the system from the get go, including all the way back to the Ace 90.

If I had one handy, I would set up an experiment, but of course, I don't have one. I would look for answers to voltage output across the rpm range, wattage potential if the voltage is higher than spec, at what voltage do 6v lamps generally expire, and what 12v lamps look like in general terms when used in an unregulated 6v system as it exists in the 94. And then I would want to know if voltage problems are related to using AC in the headlight instead of DC, or in other words, do the problems persist if the unregulated system is fully rectified.

No doubt everyone with a light system would like to have brighter lighting.