'80 to '83 Reg/Rect FREE

[pamcopete]

This is something that I wanted to do to my '81/H from the moment I got it. The stock reg/Rect works just fine, but I know it's going to fail any day. Could be tommorow....could be next year, but I know it's gonna go. So, I replaced it today with a regulator from a '70's Chrysler product and those Radio Shack Rectifiers. Works great. Now I'm gonna sell my stock OEM reg / rect on Ebay. I can in good conscience say that it came from a working bike and that is has been tested. I figure I'll get enough from the sale of the Reg / Rect to more than pay for the Chrysler Regulator and the Radio Shack rectifiers. So, just like an old car....if it's running real good...time to sell it!

Here's the wiring diagram:


Here's a pic of the Chrysler Regulator:



Here's the reg / rect and the replacement:



Here's the replacement Reg / Rect:



This assembly bolts right in the same place as the stock Reg/Rect. I used a plug from Mikes to make it plug and play. I did have to cut the upper left corner of the plate to clear the end of the left side cover and the lower part of the plate to clear the swing arm.

1. Got to your local NAPA store or www.napaonline.com
2. Search for part NAPA MPEVR38SB @$14.99 for a 1975 Chrysler
3. Wire per this diagram, using the Rectifier from my earlier post ($6.58).
5. Note: The regulator does not have a ground wire, it depends on the case being firmly grounded.
This regulator was used on virtually all Chrysler products in the 1970's. There are millions of them out there, including a very large inventory in warehouses of the major auto parts stores, so they are interested in selling them. They are very well constructed, and potted, so there is no degradation of these parts and they have a one year warranty from the parts store.

The connections to the regulator are female bullet connections, but you should remove the protective plastic from the connections for a better connection.

Parts List:
Regulator: $14.99@ NAPA
Rectifiers (2) : $6.58 (Radio Shack #276-1185, $3.29 ea))
Misc: $1.00 (Connectors, wire etc.)
2" X 1/8 " aluminum plate (shop scrap)
Total: $22.57

So, if I can sell my stock OEM Rect/Reg for $22.57 I will have received a brand new equivalent for FREE. Anything more than $22.57 is like cash back!

Bonus: The Chrysler regulator is warrantied for 1 year!

[retiredgentleman]

pamcopete: Looks real good. My 78SE still working fine with the old mechanical relay voltage regulator, but after 30 years its days are numbered. Correct me if I'm wrong but I suspect this set up would work on my 78SE.

[pamcopete]

retiredgentleman

The rectifier will, but the regulator will not. Here is the link to the regulator that will work on yours.

xs650temp.proboards29.com/index.cgi?board=Charging&action=display&thread=3246&page=1#19006

And here is the setup for the rectifiers.

xs650temp.proboards29.com/index.cgi?board=Charging&action=display&thread=3473&page=1#20564

[rossta]

Hi, I have made this setup on my 81,that the charging system failed. What I am running into is the reg is geting very hot. My question is should the green wire from the brush to the reg be hot with the key switch on.

[pamcopete]

rossta

No, the green wire should not get hot. It normally provides a maximum of 2 amps to the rotor, so that is not enough to create any heat.

If the rotor is shorted, however, then it's possible for the wire to get hot. The regulator is powered directly from the brown wire out of the ign switch, so it's current is coming from the 20A main fuse.

Suggest that you check the resistance of the rotor between the slip rings with the brushes removed. Should be 5 to 8 Ohms.

[rossta]

By hot I should I have voltage voltage on the green wire

looking at the way this is wired i belive i should have seeing voltage as i have only 5 ohms of res. between the brushes and one of the brushes is hooked up to voltage

[10ecjed]

Pete, are you insulating the rectifier terminals with anything like RTV?

[pamcopete]

10ecjed

I covered them with heat shrink tubing after I "plugged" them onto the rectifier terminals.

If you are going to do this mod with a painted regulator instead of the chrome plated variety, then be sure to scrape / sand paper the paint off around the mounting holes because the regulator does not have a ground wire, it depends on a frame ground from the mounting screws / bolts.

Also, if you are going to use the plug from Mikes, be sure to solder the plug terminals. Just crimping them is not enough.

I've had this mod on my '81/H for about 4 months and it works great. I also have a digital meter on my bike so I monitor the battery voltage full time.

The other advantage to this setup is that it separates the regulator from the rectifier, so if you have a problem, you can replace one or the other for low bucks.

The regulator is warranted for 1 year as well, at least it was where I bought it, so check with the store where you buy it.

The rectifiers can be changed one at a time for $3.29, and there is a spare set of diodes in one of the rectifiers that will get you home if you have a problem, but I have used the rectifier arrangement on my '78/E for 5 years without a failure.

[10ecjed]

WOW, sounds like a great idea.
Where did you get the digital voltmeter?
I am tempted to get the LED voltmeter from Mikes, but digital would be better in my opinion.
10ecjed

[pamcopete]

www.martelmeters.com/

Model: QM-100v

[10ecjed]

OK , Now how did you wire the alt. fail light?
I know questions, questions, questions.
10ecjed

[pamcopete]

xs650temp.proboards29.com/index.cgi?board=light&action=display&thread=6641&page=2#41699

The white "headlight out" lamp will come on when you first turn on the key. After starting, the safety relay, which is operated by the yellow wire from the alternator, opens the contacts to the starter circuit and the white light goes out. The RLU still works normally, through it's diode, so the white light will still come on if the headlight burns out. The only addition to the stock wiring are the two 1N4004 diodes.

The white light will come on with the engine running if:

1. The regulator fails.
2. The brushes lose contact with the slip rings. (happens when the brushes wear down)
3. The rotor shorts out or opens.
4. The headlight burns out.
5. Any of the associated wiring fails.


Generally, the white light will not come on for a diode failure in the rectifier or a bad stator winding, because the alternator is still producing an output. However, if the rectifier fails or the stator fails, there is still enough output from the alternator (11 to 12 Volts) to get you home.

This little mod has alerted me twice to an alternator failure. Once due to a loose connection to the regulator, and another time due to a bad brush.

[rossta]

Hi Pamcopete
I'm not sure if i should start a new thread for this but here i go
Last year i bought an 81 for my son. He rode it for a bit and all was good, until one day it blew a fuse ( I think it was the Main fuse ) , after this point it never charges correctly again. I went through Curleys charging guide and everything seemed to test fine. I put it off to bad wiring and decided to rewire the bike in the winter when i re-did the bike. Well the bike is done and i rewired it per chopper dukes wiring dig. for an 81. All is fine and bike runs but I still have the charging issue. I decided to use this reg-rect replacement as i was uneasy that the wiring was the only issue. things i notice now that i can get to the reg (mounted under the seat)
The reg gets very hot very fast
I blew a 10A fuse that runs the charging system
With that fuse removed and with my mulit-meter in its place i get a bit over 8 amps without the bike running
When speaking of the slip ring are these the rings that the brushes ride against on the rotor ?
I have taken a resistance reading between the brushes with the reg. un-plugged and get 1.4 ohms
I have tested the green and brown wires with the brushes out and get no continuity from either to ground ,with the reg un-plugged (so no short there)
When i have the power on, i get battery voltage 10.9V at the brown wire and 2.7 volts at the green wire.
I tested the stator for resistance between the white wires and all tested within specs
I have some electrical background but not much in charging systems
I'm thinking a bad rotor but i need to read up on how these work or just ask you guys
Would a shorted rotor allow to much currant to flow though to the reg as it completes the circuit ?
Any help would be appreciated
Thanks Tony

[pamcopete]

rossta

Yes, Tony...your reading of 1.4 Ohms would indicate a shorted rotor and that low a resistance would cause the regulator to heat up because normally, with 12 volts across the 5 ohm rotor windings there would be 2.4 Amps of current. With only 1.4 Ohms, that current would go up to 8.6 Amps. The rotor resistance is probably lower, because if you touch the meter leads together, you probably get a reading of .5 Ohms, which is the meter leads themselves, so you should subtract the.5 Ohms from the 1.4 Ohms to get the true resistance of .9 Ohms which would create 13.3 Amps, which would blow the fuse. You read lower amps (8A) due to the resistance of the meter itself.

The brushes also have some resistance, so when you take that into account, the actual resistance of the rotor is probably ZERO Ohms, which would theoretically produce infinite current, except for the small resistance of the brushes.

You should verify all this by measuring the resistance directly across the copper slip rings of the rotor. Find a spot where the brushes do not run so you do not scratch the slip rings.

Looks like it's time to replace the rotor, so Call Gary at "Custom Rewind" in Birmingham, Al at 1 800 798 7282. You will also need a rotor puller, and I think MikesXS is out of them, so maybe Gary at "Custom Rewind" will lend you one, other wise I can lend you mine, which is currently on it's way back from another member. PM for details.

[rossta]

Thanks pamcopete thats kind of what i thought . I will give Gary a call. I notice Mikes has new rotors for $130, is garys less? I was just asking because i think i have already put mike's kids through a year of collage and would hate to stop now.