Another PMA not charging question

warrenlevihursh

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I did search what I could, but couldn't find anything specific to a R/R with PMA setup with 6 wires. The bike was previously wired, but I am not sure if it was ever on the road or done correctly. The RR has 3 yellow, black, red and green.

OK, I believe the PMA tests good. I have 21 VAC from each yellow wire combination at idle and around .6 ohms on each combo as well.

The PO has the black and red wire (2 wires) spliced together from the RR and running to the switch for power. The yellows are obviously connected to yellows and the green goes from the RR to ground. Sound correct?

To test the RR, what DC voltage should I get from the RR? Should I be able to just disconnect the red wire and get a reading to see if the RR is working? Thanks.
20180520_145519.jpg
 
its not a question of simply joining coloured wires together ....that road leads to disaster .
You need to understand what each coloured wire is connected to internally and ascertain its function.

Just because there are 2x red wires does not necessarily mean they share the same electrical fuction and should be joined together.

The single yellow wire from a stock PMA alternator is the wire that disconnects your starter motor solenoid by means of a relay. it prevents the starter motor being accidently engaged when the engine is running. Most folk that mod their charging system wiring disconnect that yellow wire .

On a stock PMA the AC wires are I believe usually white but aftermarket AC wires are usually yellow. They connect in any combination with the yellow AC in wires on the Reg/Rect


Let us know the make of regulator rectifier fitted to your bike and the year model of the bike as well as any mods that have been done and we might be able to advise you
 
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its not a question of simply joining coloured wires together ....that road leads to disaster .
You need to understand what each coloured wire is connected to internally and ascertain its function.

Just because there are 2x red wires does not necessarily mean they share the same electrical fuction and should be joined together.

The single yellow wire from a stock PMA alternator is the wire that disconnects your starter motor solenoid by means of a relay. it prevents the starter motor being accidently engaged when the engine is running. Most folk that mod their charging system wiring disconnect that yellow wire .

On a stock PMA the AC wires are I believe usually white but aftermarket AC wires are usually yellow. They connect in any combination with the yellow AC in wires on the Reg/Rect


Let us know the make of regulator rectifier fitted to your bike and the year model of the bike as well as any mods that have been done and we might be able to advise you

Thanks for the response. I am not sure what RR it is or what PMA for that matter. It was previously wired like this, I didnt do it. I am trying to figure out how to the RR because I believe that it is bad. I beleive the motor is a '77 or '78, but that doesnt help much.
 
I should clarify that this is a chopper build and the wiring is a mess. It's also not mine, trying to help my brother get it on the road.
 
We have no way of knowing if that's the correct voltage regulator for a PMA, and you probably don't either.
I'll just show you this diagram that may or may not be right for your regulator. But I'm thinking red and black tied together is not right.

pictures-of-xs650-bobber-wiring-diagram-very-basic-led-turn-signal-wiring-question-yamaha-xs650-forum-and.jpg



a stock PMA alternator is the wire that disconnects your starter motor solenoid by means of a relay. it prevents the starter motor being accidently engaged when the engine is running. Most folk that mod their charging system wiring disconnect that yellow wire .

On a stock PMA the AC wires are I believe usually white but aftermarket AC wires are usually yellow. They connect in any combination with the yellow AC in wires on the Reg/Rect
Hey Peanut; a stock PMA, Really??? You know better than that.
So for both the OP and peanut; the stock alternator is an excited field type using an electromagnetic rotor core to excite a field and generate current in a stator.
A PMA is a Permanent Magnet Alternator that outputs AC to the rectifier/regulator.
 
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Ok, I think I'll just get a PMA RR and start over because I cant believe having two wires connected like that is correct. Never saw anything like that!!
 
Be sure to purchase only from a vender that shows the correct wiring diagram for that regulator.
 
Ok, If I was to try and wiring it like the diagram, I'm just a little confused about the green wire. Does that tie into one terminal on the coil after the switch ignition? There is no kill, just a key with ACC, OFF and ON.

Be sure to purchase only from a vender that shows the correct wiring diagram for that regulator.
 
No, the green wire from the reg/rec does not connect to the ignition coil. The green wire connected to the ignition coil is a different wire, one from the Pamco unit.

As mentioned, often aftermarket reg/rec wire colors don't match factory ones. That's why you need a diagram from the manufacturer of your reg/rec. Often these aftermarket units use the green wire as ground, so that part of your wiring may be correct. There are usually 2 power wires, one switched and one unswitched. That may be the combined red and black on yours. It may have worked that way at one time but technically, it's not correct.

There are 2 components in your reg/rec, a regulator and a rectifier. Some of the wires going into it are for one component, some for the other, and some (like the ground wire) may be shared by both. The red wire is usually connected to the rectifier and is unswitched power. But it's not power into the unit, rather it's a path out for the charging voltage from the PMA to get to and charge the battery. If you look at the above diagram, you'll see that. The other power wire is for the regulator and is switched (by the key). It is also a power sensor wire. The regulator reads the voltage in the system through it and regulates the PMA output based on the voltage it "sees".

So, you could try splitting the red and black wires, and connecting them correctly. Since it isn't working now, you've got nothing to lose.
 
Hey Peanut; a stock PMA, Really??? You know better than that.
So for both the OP and peanut; the stock alternator is an excited field type using an electromagnetic rotor core to excite a field and generate current in a stator.
A PMA is a Permanent Magnet Alternator that outputs AC to the rectifier/regulator.

It was my understanding that stock alternators on 1980 onward models were all PMA ?
I am not very familiar with the late models or the early ones so apologies for the confusing advice.
 
Good point Skull. Looks like enough fins for a single regulator, but not even enough fin for a lone rectifier.

Scott
What do you guys mean? I get the placement statement. I doesnt get much airflow there behind the motor. Do you think it's not a correct PMA R/R all in one? I am leaning towards just ordering a TC Bros PMA RR, but I don't just want to throw parts at it. Everything else seems to test good though!
 
PMA reg/rec units are an issue. Many burn up in a short time. The problem stems from the basic PMA design. It produces full output all the time once the revs increase. If you don't need all those volts, which many times you don't, it's the regulator's job to get rid of them. It "shunts" or bleeds them off in the form of heat. This is where the problems arise. The regulator gets really hot doing this job. Many of the cheaper Chinese ones aren't up to the task and don't last long. They finally have come out with much better ones but they cost $100+.

This is why many of us aren't PMA fans. They're expensive to buy and expensive to fix. I guess that wouldn't be a big issue if they never needed fixing, but they seem to quite often. I guess you could try the TC Bros reg/rec unit, but at only $37, I doubt it's a really good one. Mount it somewhere with better air flow and check your charging output frequently, probably once a week or so.
 
I'll admit I had it idling for a while a few times messing with the carbs and what not, prob got it hot. I'll see how much my brother wants to spend, but replacing it and changing the location will be my next step. I dont see what else it could be.

I have a points and a stock charging system on my personal XS650. Im not a fan of the PMA setup after this either. It does seem to make the bike kick start effortlessly though.


PMA reg/rec units are an issue. Many burn up in a short time. The problem stems from the basic PMA design. It produces full output all the time once the revs increase. If you don't need all those volts, which many times you don't, it's the regulator's job to get rid of them. It "shunts" or bleeds them off in the form of heat. This is where the problems arise. The regulator gets really hot doing this job. Many of the cheaper Chinese ones aren't up to the task and don't last long. They finally have come out with much better ones but they cost $100+.

This is why many of us aren't PMA fans. They're expensive to buy and expensive to fix. I guess that wouldn't be a big issue if they never needed fixing, but they seem to quite often. I guess you could try the TC Bros reg/rec unit, but at only $37, I doubt it's a really good one. Mount it somewhere with better air flow and check your charging output frequently, probably once a week or so.
 
I am happy i stayed with stock charging after finding out the rotor and reg/rec were not functional. I have installed a lcd voltmeter on my bike and shows me what its doing. So far all is great! Would of been lots of money to go to PMA since I have an 83 with stock ignition.
 
Looking at the PMA install instructions on the TC Bros site, they wire their reg/rec unit almost the same as yours (red and black combined, but to battery not key switch), mount it in the same spot too. So, you may have a TC Bros set-up there to begin with.
 
Looking at the PMA install instructions on the TC Bros site, they wire their reg/rec unit almost the same as yours (red and black combined, but to battery not key switch), mount it in the same spot too. So, you may have a TC Bros set-up there to begin with.

I think you are correct. I will try and wire the BLK and RED back together and go straight to the POS terminal. Who knows, it may work.
 
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