Topic: Combined reg/rec for CB 750 and custom wiring -- question!

[anotherCB]

I just bought a combined rec/rec from Dime City Cycles and hooked it up to my custom wiring harness. I think all is wired correctly, however I see a charging voltage of >16Volt at 2,000 rpm and after running the bike for 30 seconds battery voltage is at 14.5 volt (I am using an Antigravity Li Battery). Everything worked fine with the old reg and rec with the Antigravity battery and original wiring harness. Any ideas? What should I check?

I just put in this question to Dime City Cycles as well, but also want to post it here since I am eager to get on the bike 

[coma13]

Cue: "if it ain't broke, don't fix it" crowd.

[TwoTired]

Let's see if I understand this query.

--- You have a wiring harness that no one knows about but you.  Meaning: it is impossible for us to check your wiring connections.
--- You have a reg/rect. that wasn't made or offered by Honda, and we have no specification or wire pinout/connection data for it, or any reference numbers to locate this info.
--- And your question is "what should you check"?

I'd have to guess the answer is:  EVERYTHING !
But, I'd test the system with lead acid type battery, as they are far more tolerant (and cheaper to replace) while you get things sorted.


From the antigravity web site FAQ...

"3)Also, important is that OVER CHARGING above 14.7 v can damage Lead or Lithium batteries. For this reason older bikes should make sure their eletrical system and specifically the Voltage Regulator is operating correctly or you will find youself damaging your batteries if your bikes charging systems voltage to the battery is going above 15v."


They sure put it mildly, so as not to scare off any prospective buyers.  Each time you overcharge or undercharge the Lithium batteries, it's capability is diminished.
I expect it voids their warranty, as well.  But, they didn't put that fine print on the web site (that I could find).

[anotherCB]

I know that I am kind of "on my own" since I have custom everything, I was just hoping there might be someone out there with an aftermarket rec/reg that could suggest a few specific things to check. I will be in the garage tomorrow for sure and keep messing around.

[TwoTired]

OK

Well, if the regulator is regulating at the wrong voltage, then make it's voltage sense lines are getting an accurate report of what the actual battery voltage is.  For the stock reg., it is the black and green wires at the regulator.  It should measure the same voltage as is read across the battery terminals.

Good luck!

[scottly]

I suspect you have a grounding problem. The green wire on the reg/rect should be connected to frame ground as well as to the green wire on the alternator field. Battery neg should also be connected to frame ground.

[Spanner 1]

Scottly +1... looks like the R/R needs a few seconds of the bike running to 'overcome' a bad ground/connection.... but 14.5V may be excessive voltage for your type of battery. The Black wire on that D.C. Cycles unit is the voltage sense input. Test voltage at the battery and compare to voltage at R/R Black, any more than a say, 0.5V drop may cause the unit to allow too high a charging voltage ... .... time to check all connections, ign. switch and kill switch... you do have a kill switch, right?

[anotherCB]

Thanks guys, that gives me some good starting points. Will keep you updated and hopefully get some garage time in tomorrow.
Spanner1, when you mean that ignition switch under my seat when you say "kill switch" the answer is "yes" :-)

[anotherCB]

Ok, something just going through my mind, although this might be the dubmest question ever asked ......can someone explain to me what the difference is between the black wire (original sense input for regulator) and the red wire on the connector (which is connected to the battery)?

If I remember correctly, there is a voltage drop after every load (coils, light...). So do I need to connect the black wire AFTER all the loads and use that as the sense input? In other words, I run the plus from the battery to the coils, then light and all other stuff and then to the black wire?

One semester of electrical engineering was apparently not enough...Thanks and good night.

[Spanner 1]

Ya got it !... the red wire connects straight to the battery ( + ) and the R/R Black wire connects to whatever wire on your loom that supplies the ign., lights etc...... they ( R and BK ) do not both go to the battery 

[anotherCB]

:-)
That's why you don't do custom harnesses, you keep loosing track of what comes from where. Will try later and let y'all know.