HHB pma high voltage?

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RCGRT

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As Pete has mentioned several times on here it is a good practice to check the pma output before wiring in the pamco ignition. It's a 277 build pma pamco capacitor kick only, nothing but a kill switch and an led taillight and license plate light. No headlight hooked up at this point. So I finally got it to fire... Voltmeter hooked up and noticed immediately right about idle 17 or so volts dc. Had the digital meter set on the "20" setting vdc. So I shut it off right away. I didn't even bother to up the rpm and see where it went. Anyone have any idea what I can check for or try?
Thanks in advance
 
Look for other charging issue posts here.

There are a ton of them and in the XS650 Tech section.

Your problem points to rectifier issues.

Make sure ground between it and battery are good, it's connected properly with good solid connections, and if possible swap for a known good one and re-test.
 
I did some searching, I just couldn't find my specific issue and the same scenario...
It's a PMA, Pamco, and Sparx Capacitor set up, no battery.
Hugh did contact me last night and said it's a bad regulator, and promptly asked me what address I'd like the new one sent too, what an outstanding guy!

Other than that, I would like to confirm that it isn't something on my end, I did some searching on how to test a regulator and rectifier, I somewhat understand how to do it, but it is a bit over my head in the electrical dept...

Mainly I just don't want install another one and get the same result, so I'd like to verify that the regulator is bad.
Plus I wouldn't want Hugh to have to go thru any extra trouble if it's not needed, he seems to do quite a bit for the folks around here...

Any comments advice I'm all ears...
Thanks.
 
Rectifier/regulators are one of those electrical components that you can't completely check.

It's a process of elimination.

If the rectifier is good and the checks for continuity are okay, that's one half of the component, if the voltage output is okay that's the other half.

Yours is the regulator side because idle voltage is too high. Typically 14.5 volts max at 2500 rpm and you're over that at idle.

Replace and re-test is the only method I know of.

Remember the ignition is totally separate system and doesn't have any effect on charging issues, unless of course the engine doesn't run.:laugh::laugh::laugh:
The only real issue is that high voltage can ruin it and anything else in the system, but high voltage is non-selective, it will try to destroy anything in it's path. So whether it's pamco or tci or points, when it comes to charging issues, it really doesn't matter.

I know, I'm too wordy. Sorry.

REPLACE reg/rec, re-test, drive on.
 
Yeah, that's what I was afraid of. Well Hugh said he'd send me another one, so we'll see what happens. I'm 99% certain I had good ground and everything else is in order. Any chance if one of the 3 yellow was wrong or damaged in any way that could cause excessive voltage to the reg/rec in turn putting out too much voltage?
 
RCGRT,

If any of the yellow wires were damaged or not connected, that would result in a low voltage. Likewise for the rectifier. The only thing that can cause a high voltage is either the regulator or insufficient load as the regulator works by shunting the output from the rectifier to ground, so the reg / rect has to have a very good ground else there is no path for the excess current. Some regulators also depend on having a working headlight to absorb some of the load. It's like opening the throttle wide with the clutch disengaged. The engine needs a load else the revs go ape S...:eek:
 
pamcopete said:
RCGRT,

If any of the yellow wires were damaged or not connected, that would result in a low voltage. Likewise for the rectifier. The only thing that can cause a high voltage is either the regulator or insufficient load as the regulator works by shunting the output from the rectifier to ground, so the reg / rect has to have a very good ground else there is no path for the excess current. Some regulators also depend on having a working headlight to absorb some of the load. It's like opening the throttle wide with the clutch disengaged. The engine needs a load else the revs go ape S...:eek:
Click to expand...

Interesting, well like I said I'm pretty sure I have a good ground, my green wire coming out of the reg/rec goes straight to the neg side of the cap, and that wire is piggybacked and goes to a bolt threaded into the frame...

I had NO headlight during this test, do you suppose I could wire in the headlight and check again without fear of damaging anything? (I'm not too worried about a headlight bulb at this point)...

I had my meter hooked up to a different ground point on the frame, but I did check continuity between where the meter was hooked and where the reg/rec is grounded.

I did not have a chance to check voltage right out of the reg/rec before the cap, but I don't believe the cap will change voltage so that should not matter.
 
Uncle Bryan said:
Wait, are you saying you tested the voltage coming out of the capacitor?
Click to expand...

That is correct, my + meter lead was at the incoming line at my fuse terminal block AFTER the capacitor.

Red wire coming out of the reg/rect straight to the cap, and off of the other + prong on the cap to my fuse terminal block, that is where I checked it. I had the ground lead attached to the bolt that fastens the ground wire from the cap/reg/rect...
 
Just an update
I cleaned up the ground connections really well to make 100% certain I have a good connection there. This time I connected the meter leads right at the reg/rect output connection. Fired it up... 18.4v. Gave it a little gas and it pretty much stayed right about there.... I suppose the regulator is bad. I still want to try once with the headlight connected
 
TwoManyXS1Bs said:
Just for fun, put your voltmeter in AC mode, see how much noise your cap is absorbing...
Click to expand...

I'll try that next time I get it fired up. As for now I think I've found another issue.

Well I've finally got it all buttoned up and got it to fire a few times. Looked like my PMA regulator isn't working. I'm getting about 18vdc. But Hugh said he'd send me another one. Well remember how I said I was coming up with numbers about 3 degrees advanced on the cam. Well from what I can tell that would advance my pamco with it. I noticed immediately a consistent kick back as I was trying to kick it. Once I finally got the timing light on it, it was at or past advance at or around idle.... I've already adjusted the pamco plate as far as it will go, and tried taking the slop out of the mechanical advance that drives the pamco rotor... Is it possible that cam is so far advanced that I will not be able to get the timing right? The cam only rotates half of the crank, so seems like it would have to be way out to have to adjust it that much?
 
There is a small pin in the cam that drives the mechanical advance. Well I just rotated the unit counter clockwise (in order to retard timing) until the slop in between the pin and the unit was all out, and then re tightened the nut on the advance unit. It's not much movement, but I was trying to get all I could out of it.
 
Yeah it sure was humid today! Yes I did see that thread, I torqued it just a little past spec and the both male and female tapers were nice and clean and dry, I doubt it slipped but I won't just dismiss it, if the crank spun in the rotor, that would spin the line towards advance so... I'll check it...
 
New regulator rectifier came in, thanks for getting out asap Hugh. Unfortunately I hooked it up, fired up the bike and saw about 19vdc... I'm at a loss, the reg/rect is going straight to a terminal block +, and the - is going to the
- side of the cap, that same - wire is piggybacked to the frame, all of the connections are good.
I put my volt meter on my battery I'm using on the ignition circuit and it shows about 14vdc, seems high for an old battery that has been sitting around, but I don't know how else to verify the meter. It's a pretty much brand new craftsman digital meter....any suggestions?
 

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