6V Spotlight bulb

[RvP]

I know the 6V springer headlight uses a 2320 light bulb which draws 3.3 amps (low beam) and 4.52 amps (high beam). What is the P/N of a spot light bulb and how much current does one bulb draw. I am contemplating putting spot lights on my WL with a 32E generator and I am already running bullet tail lamps. Don't know how much more I can tax the 32E.

What was the setup for running spot lamps, on with low beam, on with high beam or switched independent on of either?

[Chris Haynes]

On factory Knucks and Pans when you went on high beam the spotlights were cut off. They only operated on low beam.

[Perry Ruiter]

I know the 6V springer headlight uses a 2320 light bulb which draws 3.3 amps (low beam) and 4.52 amps (high beam). What is the P/N of a spot light bulb and how much current does one bulb draw. I am contemplating putting spot lights on my WL with a 32E generator and I am already running bullet tail lamps. Don't know how much more I can tax the 32E.

What was the setup for running spot lamps, on with low beam, on with high beam or switched independent on of either?

On factory Knucks and Pans when you went on high beam the spotlights were cut off. They only operated on low beam.

The spotlights are only on when the headlight is off. Chris and I disagree on this point. When this was last discussed I supplied the 1949 factory instructions for installing spotlights. This time I'll supply a 1947 factory wiring diagram in which the factory states "Note: With this method of wiring, when spotlamps are turned ON, headlamp is automatically turned OFF and vice-versa".

As you note the stock headlight bulb is a 2320 which is a 32/21 candlepower bulb and is rated at 4.5 amps on high beam. Likewise each spotlight is a 32 candlepower bulb. There are a couple styles of spotlight and I believe the bulbs typically used are either an 1133 or a 1321 which are rated at 3.9 and 4 amps respectively. Not quite the draw of a high beam but up there. So wired as Chris proposes the 32E would be expected to generate enough for essentially two high beams and a low beam concurrently. The 32E simply isn't capable of doing that. The laws of physics apply regardless whether Chris acknowledges or understands them. A stock 32E is lucky to keep up with a single high beam ... Perry

[RvP]

How Did they do it?

Perry,
Thanks for the information, that is exactly what I was looking for with regards to bulb type (I also use “Don’s bulbs” as a reference). I have never seen any hard specs on the output of a 32E but I always used 10 amps max (on a good day) as the best it can do. With my existing electrical load of all running lights on, including the two bullet lights on the rear and speedometer light, I measure a charge current INTO the battery of 2 amps with the low beam on, 1 amp with the high beam on. This is with the 3rd brush turned all the way up.

With each spot lamp bulb drawing 4 amps, 8 amps total, the 32E (assumed to be 10A max output) will barely keep the battery charged with the headlight off with a stock electrical load, i.e. no bullet lights. Turning the speedometer light off will make it a little on the good side.

For me, it’s a no go. Since I only have 2 amps of charge into the battery with the low beam on, even turning off the headlight to save 3.3 amps gives me 5 amps left to break even. With the spot lamps drawing 8 amps (total) I will be discharging my battery at a 3 amp rate.

The wiring diagram you have that shows the spot lamps also shows “saddle lamps” which would be equivalent to my rear bullet lights. This leaves me with the question of how they did it back then with spot lights (8 amps), 1 tail light (1 amp), 2 saddle lamps (assumed to be 1 amp each, 2 amps together), all totaling an 11 amp lighting load. Add in the current needed for the ignition coil, current to energize the lighting field in the generator and the speedometer light you are up to around 15 amps in electrical loads not even taking into account any current left to keep the battery from discharging.

Either the 32E is better than 10 amps output or there were a lot of guys with saddle lamps and spot lights sitting silently in the dark on the side of the road. Was it really that bad or am I missing something?

Thanks again for your help.

[Chris Haynes]

The spotlights are only on when the headlight is off. Chris and I disagree on this point.

It is not so much of a disagreement as just stating what I have found on original bikes. perhaps the owner or dealership changed the wiring.
For sure during the ElectraGlide years of the '60's-'70's where spotlights were standard they were that way from the MoCo.

[Perry Ruiter]

Either the 32E is better than 10 amps output or there were a lot of guys with saddle lamps and spot lights sitting silently in the dark on the side of the road. Was it really that bad or am I missing something?

Thanks again for your help.

With the third brush cranked all the way over you can get more than 10 amps out of the 32E but 10 amps is safe maximum to use as a rule of thumb. The generator heats up as it works and if you demand too much from it, it gets too hot and starts to throw the solder off the commutator (I really regret not having taken a photo of a beautiful solder trail all around the inside of the commutator end casting of one tired overworked 32E I pulled apart a few years ago).

You ask what you're missing, I think it's the battery. That's a 22amp reservoir (assuming it's fully charged). So if you're out with a buddy for the evening and you need to ride home in the dark and fully lit up you're a couple amps over you're OK even if home is a couple hours away. If home is 10 hours away or you always ride in the dark then obviously you have a problem and you need to reduce the demand ... Perry

[RvP]

Back in the game

Thanks again Perry, the battery would act as a reserve and given the 22amps you mention is 22 amp/hours, in my case being 3 amps over with spots, I have about 7 hours of run time with the spots on before the battery goes dead. That’s longer than I have ever ridden at night. Excellent answer and that line of thinking puts me back in the market for spots.

I always ride with my high beam on in the day time so I can be seen better. With the wiring diagram you sent I can still ride with the high beam on because the spots would be off. This would work out great for me. If by chance I ever do take that long ride at night for over 7 hours I can always turn the headlight on which would kill the spots, and let the battery charge some.

By the way, I have been lucky and not thrown any solder off the commutator on my 32E. I have an external shunt regulator mounted in my battery box to keep the electrical system in check allowing the 3rd brush to be turned all the way up and not boil over the battery or burn out light bulbs. I have been using the shunt regulator for 3 years and have not had a generator failure yet. Since it is experimental I check the generator output occasionally to make sure with the full lighting load (high beam on) the battery voltage is maintained at 7.2V. I also pull the generator at the start of the riding season to clean the commutator and check the brushes. I have not seen any solder trails yet, so far I have been lucky.

Thanks again for your help and insight.