Topic: Cb550 regulator/rectifier connection problems

[Emina1]

Hey guys Iam currently building my first cafe racer/brat bike. My donner bike a Honda cb550 1976. I have completely removed the original harness and fitted the motogadget m-unit. I've wired pretty much everything except the regulator/rectifier 2in1. My engine alternator plug has 7 wires,3yellow 1 white,1 green and 2 multi coloured wires. My reg/rec plug has 5 wires and 3 loose wires. The plug are 3 yellow,1red ,and 1 green. The loose wires are white black and green. Can any one help me where each wire goes. Remember Iam using the munit.

[calj737]

The m-unit has little to do with your R/R. Connect the loose BLACK to LOCK, swap loose WHITE into the plug for RED. RED to battery POS. Loose GREEN to chassis ground.

PM if you need further help.

[calj737]

By the way, the two striped wires are your NEUTRAL and OIL PRESSURE switch wires. These run to your idiot lights as the "ground" side of the indication light, using power supplies by AUX to make them work.

[Emina1]

Hi thanks for reply. Few questions. Why change the red with the whit? Can't I just put the white to the battery via the fuse? Also I've just been told that black goes to aux out not lock! Does this sound right to you?

[calj737]

The first time I installed a Ricks with an M-Unit, I called and spoke directly with Ricks. They advised swapping the WHT/RED as RED carries current directly to the battery. I've always done it this way since and never seen a single charging problem.

Using AUX vs LOCK. Your key switch BLACK brings switched 12v to the M-Unit to excite it. Since the loose BLACK is a 12v sensing wire, best to read the voltage as close to the battery as possible. There is the potential for resistance introduced across connections or devices to show a lower voltage than the battery actually has, thus instructing the R/R to produce higher output voltage and damaging your battery.

[calj737]

Another consideration about using AUX is the number of total wires that will be plugged into it. Without using their multi-port connector, you can only plug 2 wires in. You'll need AUX to supply: ignition coils, gauge backlights, tail light, idiot lights, and possibly a license plate light. You'll be splicing so many times to make those connections, that your R/R is bound to be reading an incorrect voltage.

[Emina1]

Brilliant. What you say makes sense. I'll swap the red and white,I've noticed the red cable is slightly thicker than the white. Thanks very much for you help. Follow my build on fbook.
https://www.facebook.com/groups/1014870688536142/

[calj737]

I don't use Facebook. But if you need help, post a build thread here.