charging system question, i have 20v at battery, what in wrong?

[shark1979]

i had a bad rotor. i replaced it with a new one from xscenteral. my stator checks out ok. i replaced the rec. with the ones from radio shack, and the reg with the one from napa. ungrounded the brushes. followed the instructions on here as how to wire all this up. i am getting 14.0v at idle at around 20-25 when i rev it up? i know that is no good. what did i do wrong!

can you please shed some light on this for me?

 

[xjwmx]

The solid state regrec years are handled differently from previous. What year ya got?

After you;re sure you;re working from the right year radio shack reg Chrysler rec schematic, go over your wiring there wire by wire

 

[xjwmx]

In the meantime don't rev it to 20V or you'll blow somethin up. Set your idle pretty low and test your changes at that speed first.

 

[shark1979]

. at idel i have 14.-15 volts going to battery. when i rev it just a bit it goes to 20v+. what are some things i should be looking for?

 

[xjwmx]

Well. it's just not being regulated, because your wiring is wrong I would guess. I can't see your wiring so I can't tell what;s wrong.

 

[shark1979]

which reg should i use ? napa or advanced auto? do i need to unground the brushes when i do this?

 

[xjwmx]

What year's the hawg?

 

[shark1979]

What year's the hawg?

it is a 1978.

 

[glennpd]

Did you use plastic screws for the brush holder?

 

[shark1979]

Yes I used nylon screws in the brush holder . I used 3 . Ungrounded the right brush. I was reading on here that I did not need to unground the brushes due to the age?

 

[pamcopete]

Wish I knew the part number of the regulator you used from NAPA. If it's the Chrysler regulator MPEVR38SB then you have to ground the case because it does not have a ground wire. If you mounted it on the battery box, then be aware that the battery box is not grounded, it floats on its rubber bushings. You have to run a separate wire from the frame to the mounting screw for the regulator.

 

[shark1979]

Wish I knew the part number of the regulator you used from NAPA. If it's the Chrysler regulator MPEVR38SB then you have to ground the case because it does not have a ground wire. If you mounted it on the battery box, then be aware that the battery box is not grounded, it floats on its rubber bushings. You have to run a separate wire from the frame to the mounting screw for the regulator.

Pete, that is the number of the Reg I used. I did run a separate ground wire to the Reg. What would happen if you flipped the wires on the Reg? Meaning put the wrong wire on the wrong post. Which post does the brown wire with the 7.5a fuse go to? Do I need to use the nylon screws with that set up on a 78?

 

[pamcopete]

shark1979,

1. If you crossed the wires, you would fry the regulator. Hope you kept you receipt because NAPA will replace it under warranty.

2. Nylon screws are required with that regulator in pre '80 models. You also have to wire what was the grounded brush to battery through a 7.5A fuse.

3. Here is a diagram of the correct wiring for the Chrysler regulator:

 

[bloodthirstysystem]

i hope you're wearing safety glasses when you're revving that battery up to 20V!!!

 

[shark1979]

shark1979,

1. If you crossed the wires, you would fry the regulator. Hope you kept you receipt because NAPA will replace it under warranty.

2. Nylon screws are required with that regulator in pre '80 models. You also have to wire what was the grounded brush to battery through a 7.5A fuse.

3. Here is a diagram of the correct wiring for the Chrysler regulator:

Pete. The wire with the fuse( brown wire) comes from the hot side of the key?

 

[pamcopete]

shark1979,

Not sure what you mean by the hot side of the key. If you have a stock ignition switch then the red wire is from the battery and the brown wire is switched on and off with the key. That's the brown wire in the diagram.

Remember that switched battery also goes to what was the grounded brush (black wire). The black wire itself still goes to ground in the harness somewhere, so best to just run a new wire from the brown wire through the 7 1/2A fuse directly to the brush.

 

[shark1979]

Yes my brown wire runs from the switch side of the key to the voltage Reg. The old Reg ( factory one) I cut the plug off wired the green from the plug to one post on new Reg. Brown wire form plug wired to other post on new Reg. Black wire form plug which is ground went to housing of new Reg. I have a new wire harness form TC bros.

 

[pamcopete]

shark1979,

Well, I would verify that the black wire is indeed grounded somewhere since you removed the ground from the brush that may be the only ground for the black wire in the TCB wiring harness.

Otherwise it sounds like you have it wired correctly, so perhaps you just momentarily had the wires reversed? If so, then go get a replacement unit from NAPA on warranty.

It's also not unheard of to have a failure out-of-box or perhaps someone returned that unit after frying it.

 

[shark1979]

Well, got a new one from napa. Wired just like you showed. Started the bike I am getting no voltage back to battery. What do I look for now? Where does the black wire from the other brush go?

 

[pamcopete]

shark1979,

I'm sorry. you are doing something wrong. I do not know what it is. Please review your wiring and remember that just looking at wires is not the same thing as actually testing everything with a meter. Like, when you say that you are "getting no voltage back to the battery", I have no idea of what you mean. Take some measurements.