Best way to check if a regulator/rectifier is going bad?

[Lucien Harpress]

Small update:

Seems the weird results of the stator/field coil test were my fault. After zeroing out the meter, everything checks out. I guess the reg/rec test is next...

[Lucien Harpress]

So, some really interesting information.....

I decided to go ahead with the rectifier tests, being a bit easier to do (not needing the bike running). I followed the instructions in the manual (disconnected the battery, disconnect both regulator and rectifier leads), and came up with something interesting.

After following the wire tests, here's what I got:

Red wire-Brown wire: Nothing (infinite resistance), no matter what leads were one what wires.

Black wire-Brown wire: Nothing one way, small reading the other way.

Red wire-White wires: Got a reading one way, got nothing the other way, for each

Black wire-White wires: No readings one way, got a reading the other way on only two of the other wires.

Far as I can tell, I was supposed to get a reading off of it along with the other two white wires. The fact that I DIDN'T is encouraging, as this is the first time I've found something wrong. Other than the non-battery charging thing....

Any wisdom on the matter?

(If it wasn't obvious, all the tests I did were resistance tests.)

[Geezer]

It looks like 2 of the 6 diodes in the rectifier are toast...

Geezer

[cywelchjr]

+1 on the toasted diodes.

[UTTS]

Voltage Rectifier TACH

I have a 1979 XS 1100 SF in really good condition. My tach does not wobble, but spikes and Operates normal till about 3 g's, then it spikes +/- 1000G's and sometimes hold up around 3.5 G's, even if you rev it up. Everything appears to operate normal, with the exception of the tach spikes and when the RPMS are around 1000 G's, and using the blinkers the indicator gets weak and some times they do not flash until I rev it up. I have completed the rectifier test several times. Each time there is NO Ohms between any connection in any order on the two plugs. Is this possible to have a defective rectifier, yet still have all the systems operate normally???

UTTS

[Geezer]

More than likely you just have a sticky tach...

Geezer

[UTTS]

Voltage Regulator Rectifier / Electronic GUYS

My 79 XS 1100 SF special, has 8 elements in the Rectifier. I have run the test (both directions) and found the following results with the meter at Rx1 and RX100

> Rx1
> >
> > > D1 60 / none
> > > D2 60 / none
> > > D3 60 / none
> > > D4 1000 (+) / none
> > > D5 60 / none
> > > D6 60 / none
> > > D7 60 / none
> > > D8 350 / 1500 (+)
> > Rx 100
> > > D1 40 / none
> > > D2 40 / none
> > > D3 38 / none
> > > D4 149 / none
> > > D5 40 / none
> > > D6 38 / none
> > > D7 28 / none
> > > D8 28 / 28


I have had several email talks with Geezer. He thought that the it only had 6 elements, until I mentioned the test in the service manual.

I know that several have used Geezers unit with great results. My question is having 6 vs 8 elements effect the systems and 2, Which Elements run what?? It appears to me that D8 is directly related to the other elements, is this true and if you have a bad element, how does it manifest itself?????

DAN

[b.walker5]

D4 and D8 is the circuit that supplies DC to the regulator after it's been rectified from the three phases from the alternator.