I ran with no headlight a few days ago and I was getting 14.7V at just above idle, so load shedding seems to be a very effective way to improve charging performance.
-
Enjoy XS650.com? Consider making a donation to help support the site.
XS650.com receives a small share of sales from some links on this page, but direct donations have a much greater impact on keeping this site going.
Using stock rectifier with VR38SB regulator
- Thread starter MacMcMacmac
- Start date
I noticed that 14.6 - 14.7V is the value I got when using the Fiat regulator. Just keep a check on the battery to make sure it isn't losing too much water, but I think that is really a big issue past 15V. Good to see we are both learning something about our charge systems. I have ordered a better quality LED H4 but will take a couple of weeks to arrive.
Anybody hazard a guess why 3 different 1157 LED stoplights won't work in my Lucas style tail light? Do I have to insert diodes like I did with the mini gauge turn signal issue?
Did you have it working before with a normal bulb or are you just now mounting it for the first time? I ask because many of those aftermarket tail lights don't have a ground wire in them. The housing is the ground. On a stock 650 that can present a problem because the rear fender is rubber mounted. Just bolting the new tail light to the fender won't ground it. You need to run an actual ground wire from one of the light mounts to the main frame.
Yup. I have been running this light for several years with a proper ground. 1157 bulb lights instantly.
Well, there's three contacts, two on the bottom of the bulb, one for ech set of LEDs, and the outer case. The outer case connects to the socket which connects to the light frame, through the fender to ground. According to how I read the wiring schematic, each contact at the bottom of the bulb is energized by the power on, and by the brake switch sending +ve to the bulb bottom and grounding through the bulb case, so I don't understand how polarity could be backwards. I'll give it a run and see if maybe it's not hitting a voltage threshold before illuminating. Otherwise I'm going to have to send +ve to the light frame, insulate it from everything else and switch the ground via the brake light and a dedicated wire for one set of leds, which sounds like a whole lot of work.
Polarity of the bulb checks out with my charger. It has to be wiring then.
Well I did you one better by riding around with a positive ground on my rear fender. I mixed up a positive lead and ground when I wired up the light. I found out when I touched the fender and felt a tingle on my cheek when I touched it off the turn signal. Don't ask me how anything worked but it did. I now have it hooked up correctly, but the led is so dim even the fireflies were snickering. I figured Phillips would be a decent brand but I could barely see it in daylight.
Mac not sure what color you used but LEDs are VERY narrow wave band, compared to an incandescent bulb that sprays a WIDE spectrum of light, so a white LED behind a red lens will be shamed by a healthy birthday candle.The red lens absorbs all the white light. So you need to use a RED 1157 LED and a white license illumination. Bit of a pain to do.
Yes, it's a red one. I should know by now anything that Princess Auto sells is usually some other company's castoff stock.
Well, an LED headlight allows my bike to fully charge when running. Sad that the stock system has so little margin in it, but it is what it is.
It goes below 12V at idle with the brake and turnsignals on when I'm out riding. That's with a new AGM battery. It recovers pretty quickly when moving again.
In the interest of science I have spent way too much money on a 3 X 2 X 1/2 neodymium ring magnet which nestles perfectly inside the rotor cage of my Ricks alternator. I shall assemble it, install my Shindengen SH775 regulator and see if I can't use the stock TCI ignition with this home made pma rotor. If it works, it should be an easy swap for anyone to do.
It goes below 12V at idle with the brake and turnsignals on when I'm out riding. That's with a new AGM battery. It recovers pretty quickly when moving again.
In the interest of science I have spent way too much money on a 3 X 2 X 1/2 neodymium ring magnet which nestles perfectly inside the rotor cage of my Ricks alternator. I shall assemble it, install my Shindengen SH775 regulator and see if I can't use the stock TCI ignition with this home made pma rotor. If it works, it should be an easy swap for anyone to do.
Yes, it's common and pretty much normal for the volts to drop below 12 at idle with all the lights on. These systems just don't have much output at low RPMs. My '78 has always been like this but I never had battery issues. That may be because this older model only has one brake/tail/license plate bulb. Those later Specials have 4, 2 brake/tail and 2 license plate. That's got to be lots more draw than mine.
Just a link to show how to spot the difference between genuine Shindengin regulators and fakes which are the old style shunt type:
Similar threads
