Electrical Questions

[smokestacks]

Am i supposed to get continuity between my positive leads on my lights and the grounds to chassis when testing with a voltometer? I was under the assumption that they shouldn't have any. I have a bates style headlight from Mikes with Blue, White and Green wires. If you open the bucket, it has blue and white going to the bulb, and the green goes to the back of it on the brass part, so im assuming its ground. If i check the between either positive, and anywhere on my frame, I have continuity. Same thing with my tail light (a sparto replica from lowbrow). In the process of chasing down electrical gremlins, and want to make sure I get it all right before I button it up and heatshrink and solder my connections.

I've attached the wiring diagram I made for my bike and am following.

1978 xs650 with Hughs PMA, Pamco standard ignition, and Capacitor.

 

[5twins]

That's not something I ever recall testing for but now that I think about it, I'm going to say yes, as long as a good bulb is installed. I'm thinking high or low beam power in would travel through the bulb filament and go to ground. Try pulling the bulb out or unplugging the plug from the headlight, then test. If you lose the continuity then there you go.

 

[smokestacks]

With the bulb out there isn’t so I guess that’s normal.
Wouldn’t that mean when the bike is running that the excess power going to grounds would go to the bulbs as well causing them to blow? Sorry if this is a stupid question, Electric isn’t my strongest point.

I have blown 2 capacitors and a headlight bulb chasing my electrical over the past few weeks and can’t seem to pinpoint my issue.

Everything is to its own ground, with no paint on where it makes contact, everything is crimped properly using RM stator crimps, and then heat shrunk, so I have no idea where it could be shorting out if it is.

my regulator body (Hugh’s HandBuilt) has continuity to chassis, as does the green ground wire from it.
im running the PMA from Hugh, and a Mechanical advance Pamco. The bike has no problem starting, 1 kick even with lights on. But when I gave it throttle, the capacitor blew on two separate occasions.
The capacitor is also grounded to the chassis.
The only thing I can think is that maybe the regulator and capacitor sharing a ground caused the cap to blow? but I was also under the impression that you could run your negative from your regulator to the capacitor negative and treat it as a battery, as I have done on a previous XS build with no issues, so I’m really at a loss as to what it could be, so I’m chasing my entire loom with a voltmeter, hence the first question.

 

[smokestacks]

Also, tested my regulator as per Hugh’s instructions on his site, and got 458,468, and 442 on the yellow legs. He said those weren’t too far off and it should be good. Might also be worth mentioning that It’s the standard one, not the mosfet, as I’m running incandescents and didn’t see the need for getting the Mosfet.

 

[smokestacks]

Would mounting my capacitor like this cause my issue? Since the regulator grounds through the body, would the ground be going through my spring, to my cap?

 

[gggGary]

Get a voltmeter on the bike that you can see while riding, should never see much above 14 volts. I suspect the regulator part of the RR isn't, not sure how that would blow a cap but it will for sure blow bulbs. Then again vibration will blow up parts too. Yammy went to a lot of trouble rubber mounting and isolating electrical parts from vibration.

 

[X77S]

If the regulator isnt working and letting it overcharge wouldn't it eventually ruin a battery? In this case a capacitor may blow way faster due to size? You said it starts and idles fine, but as soon as you give it throttle it blows? Have you run tests on the reg rec with it unattached to the system? I'm not sure there are tests, just thinking out loud. I would take the capacitor off of the mounting bolt for the regulator and let it hang loose. I dont think the body of the capacitor should ground.

 

[smokestacks]

If the regulator isnt working and letting it overcharge wouldn't it eventually ruin a battery? In this case a capacitor may blow way faster due to size? You said it starts and idles fine, but as soon as you give it throttle it blows? Have you run tests on the reg rec with it unattached to the system? I'm not sure there are tests, just thinking out loud. I would take the capacitor off of the mounting bolt for the regulator and let it hang loose. I dont think the body of the capacitor should ground.

Yea I ran tests on it, and Hugh said it was tested ok. I’m going to try moving the capacitor to where my starter motor used to be, and see if that does anything

 

[X77S]

Let us know, I'm coming up on time to install mine. It's been nice to read through some problem threads to figure out some of the issues before doing the work myself.

 

[smokestacks]

So I moved the cap down to where my starter was, ran a seperate ground from it to my bottom motor mount. And it seems to be working, haven’t blown a headlight or this cap yet, but it’s been crappy out and I’ve only gotten to take it around the block a few times. Will keep you updated tho once I get to ride it a little more. So I’m not sure if having the spring mounted to the regulator body was the issue, or them sharing a ground. I’m leaning more towards the spring on the body, cause on my old xs650, everything shared one ground and it was fine….but every bike is different so who knows