RR51 wiring

welshmally · Post by **welshmally** » Mon May 30, 2011 1:14 am

Hello All,

I've posted on this subject in the past, but due to major upheavals at home (building), and work

the bike has been on hold.

The story so far: I bought an Electrex RR51 to replace the standard reg/rec. After a long argument with Electrex UK, I was unable to get it to work. It appears that many people have used it OK.

I have a '79 900SS. I also have the original wiring diagram. The only modification I have made is installing a RITA ignition.

The Electrex wiring diagram states that the red and green go to the battery, 2 yellows to the alternator, (easy so far) and the white to "GEN light via battery" which is the bit that eludes me. I assuming that somebody on here has installed one successfully, so your help would be very much appreciated.

I have to confess that electrics are my achilles heel, so I need step-by-step explanations in words of less than 1 syllable!! Today is a good day to work on the bike - cats and dogs outside!

BTW the bike runs fine on the old reg/rec, but battery goes flat

Many thanks

Hugh

bobnorton · Post by **bobnorton** » Mon May 30, 2011 7:39 am

A similar situation with a kit car ,untill the generator warning light was wired up the battery would not charge, so at least you know now that this is the last hurdle, but as to why --it makes no sense to me. Someting to do with exciter current??.

baddean · Post by **baddean** » Sun Jun 05, 2011 8:55 pm

Hi Welsh,
The regulator/rectifier on our bikes is an interupter type charging system as opposed to a shunt system used on newer (post 1990) bikes.
This means that our reg/rec allows a charge voltage only when needed to replentish the battery. This is also why you see no heat sink. This system doesn't develope heat during the operating process.
A shunt system provides a charge voltage constantly with the current going to ground when it is no longer needed to charge the battery. This system developes heat thus requiring some sort of heat sink to cool the reg/rec.
You need to run the white wire to the battery side of the charging light as the instructions say to because the charging light is telling the reg/rec when it needs to send voltage to the battery. ( this is simplified but easier to explain this way).
Hope this helps,
Dean

welshmally · Post by **welshmally** » Mon Jun 06, 2011 1:23 pm

Hello again, Dean - how's life?

The standard unit has a big heatsink - are we talking about the same bike? (1979 900SS). Also I'm not sure what you mean by the 'battery side' of the charging light. Would it help for me to upload a wiring diagram?

I have the best brains in the UK working on this one - it seems to have foxed everyone!

WM

baddean · Post by **baddean** » Wed Jun 08, 2011 1:12 pm

welshmally wrote:Hello again, Dean - how's life?

The standard unit has a big heatsink - are we talking about the same bike? (1979 900SS). Also I'm not sure what you mean by the 'battery side' of the charging light. Would it help for me to upload a wiring diagram?

I have the best brains in the UK working on this one - it seems to have foxed everyone!

WM

Hey Welsh,
Life is great, thanks!!
Don't confuse the large finning on the reg/rec (RR) as a heat sink. The finning is strictly for minor cooling purposes. A heat sink draws heat from a component to keep it from overheating. (think Zener Diode on a British bike).
Now I am assuming that the wiring diagram you have has the three fuse block and is for the five light system on your dash. If not, then I would ask that you post up your wiring diagram.
Your upper left light on the dash should be a red light and would be your alternator light. Attached to that light should be a pink with black tracer wire (ground) and an orange wire (hot). The orange wire, while running to a number of other components, is the same orange wire that is coming off of the middle fuse in the fuse block. This is where the white wire should go.
The assumption that many people make is that the Electrex/Electrosport RR51/ESR510 RR should match up wire for wire. This unit fits many Italian bike brands that use many of the same components, however different brands and models within each brand use many different wire colors in their wiring looms. So by instructing the user to attach the white wire to the Gen/Alt light, installation would be the same regardless of wire color. The confusing part of their instructions is showing the white wire going through the charge light back to the battery +. This is generally not the case with our older bikes but might be correct for modern bikes.
If you check your wiring diagram and trace the orange wire from your Alt light all of the way back to the middle fuse you will notice that at the other side of that fuse was the Black/Brown wire from your OEM RR. This Black/Brown wire, after it attaches to the middle fuse, goes of into the wiring harness as an Orange/White wire.
Let me know if this is helping,
Dean

welshmally · Post by **welshmally** » Thu Jun 09, 2011 9:11 am

OK that all sounds different to other opinions, as as they don't seemed to ahve worked, it amy well be the answer.

One thing is confusing me : the pink/black (P/Bk) is not connected to anything and appears to have been like this for a while, but with no obvious place to connect it - should it go straight to ground? I can trace it all the way (with continuity) to the GEN light. Where would be the most obvious place to hitch it into the harness?

BTW I am considering getting a stator rewind as it's 30 years old and probably a bit iffy.....!

Hugh

baddean · Post by **baddean** » Thu Jun 09, 2011 8:27 pm

G'day Welsh,
The pink/black is the only one of that color that shows on the schematic. It goes from the Alt light through a 12 pin connector (pin 4) and then on to ground. It is definately a ground wire.
Does your Alt light work now? If it does then don't worry over the loose wire. If it doesn't then you need to ground that pink/black wire (anywhere you can get a good ground) Is the pink/black you have that is loose connected to the Gen light or the connector? If you have continuity from ground to the gen light then your loose pigtail might have been left there for some other purpose.
As far as a rewind on the stator goes, are you sure the magnets in the rotor are strong enough? The rotor magnets can weaken over 30 years as well. On the round case motors it is common for the rotor to be very weak causing low charge voltage. I replaced the rotor on my round case 750 with one from a '98 ST2 that uses rare earth magnets and my charging issues went away. The original rotor from my 750GT wasn't strong enough to pick up a screwdriver.
I'm enjoying our troubleshooting conversation. Hopefully we can get to the bottom of this mystery.
I can't believe that someone else hasn't jumped in here. Surely there must be some electrical gurus hanging around here or at least someone who has installed one of these on a square case.
Dean

welshmally · Post by **welshmally** » Fri Jun 10, 2011 3:02 pm

Hi Dean,

I'm out and about tomorrow - I'll earth the P/Bk and then connect the brown to the white and see what happens. I'll be back on line on Sunday.

The GEN light does not illuminate, although it definitely does work: there is continuitiy through the block to the light from the loose tail, so I'll try grounding it and wait for the bang!!!

Cheers
Hugh

welshmally · Post by **welshmally** » Sun Jun 12, 2011 7:49 am

Hi Dean,

It's raining hard here so I'm not missing being on the bike at all!!

I did as you suggested, and connected P/Bk to ground, white to Br (which was the old Br on the original reg/rec) but with no joy - nothing works. I kicked the engine over and did not get a spark. I had the bike running 2 weeks ago on the old reg/rec, and the carbs were so far out that I couldn't get it to idle at any speed, but I know for a fact that the batttery isn't charging. I will get the whole lot back together and re-test the alternator and the reg/rec again. I need to establish the root of the problem again - I am suspicious of both!

If it's dry tomorrow I'll get it out of the garage and fire her up, now that I've stripped and cleaned the carbs.

Owning a Ducati - a never-ending life of fiddling!

Hugh

welshmally · Post by **welshmally** » Sun Jun 12, 2011 8:47 am

Old reg/rec back in - still too wet to get the bike out of the garage.

Gen light works when P/Bk grounded - no surprise there! Indicators - come on, don't flash. I will get a new solonoid although this one is fairly new, but for a few pennies it's worth eliminating.

Fire her up tomorrow and see what happens, multimeter at the ready.

Hugh

welshmally · Post by **welshmally** » Mon Jun 13, 2011 12:41 pm

Would you believe it - 14V at the battery, so it must be charging!

After all that with Electrex, as well.

I now have a carb niggle - will post in appropriate board.

Thanks, Dean for your help so far, although I'm not completely ruling out a rewind and re-wire........

Hugh

baddean · Post by **baddean** » Wed Jun 15, 2011 12:16 pm

welshmally wrote:Would you believe it - 14V at the battery, so it must be charging!

After all that with Electrex, as well.

I now have a carb niggle - will post in appropriate board.

Thanks, Dean for your help so far, although I'm not completely ruling out a rewind and re-wire........

Hugh

Hey Hugh,
I've been away from my computer for a couple of days.
Since you found that pink/black wire disconnected and reconnected it to ground I figured that your charging system might work. That gen light needs to work (or at least be hooked up correctly) for the charge system to work.
Glad it's working out thus far.
Any charge voltage from 13.8-14.2 volts at the battery is good charging. You shouldn't need to rewind the stator, sounds like it is working fine.
On to the carbs.
Dean

welshmally · Post by **welshmally** » Wed Jun 15, 2011 3:13 pm

Ah, but how long will it last.........? Every mile, living on the edge: will it get me home? Have I got enough fuses in my pocket? Did I pack the multimeter? The excitement never ends!!!

Hugh

baddean · Post by **baddean** » Wed Jun 15, 2011 4:08 pm

welshmally wrote:Ah, but how long will it last.........? Every mile, living on the edge: will it get me home? Have I got enough fuses in my pocket? Did I pack the multimeter? The excitement never ends!!!

Hugh

Well Hugh,
You could live on the ragged edge and leave the multimeter at home.
Where's your sense of adventure?
Go ahead and live for the shear excitement