Generating system question

[Cary and Don]

Hi all,

We have an on going little problem. When we got the bus, come to
find out the regulator had been diconnected and the generator
therefore wasn't working. It appeared they had something mounted in
the engine compartment to take the place of the regulator and removed
it before we got the bus. This we discovered one rainy day with the
head lights on. Thank goodness for battery chargers.

We installed a new regulator board since the old one refused to
work. It seems we didn't do a real good job and kind of shorted it
out a little, but a wire across the burnt spot cured the problem.
Please don't say, "I told you to check all those little plastic
spacers better". All was well with the world. It charged and the
tach worked great. After about a year, it seemed we had to go tap on
the relays by the regulator to make it kick in and that was becoming
a real pain. Then the tach needle and the volt meter started to
bounce at low rpms. We decided to change the board to a new one that
we wouldn't fry this time around.

Again, all was well with the world, this time for sixty seconds, and
it quit. The tach would read at fast idle, but not idle. The volt
meter never did kick in again. After some checking, the regulator was
hot, real hot. Took the board back out and it was crispy critter in
the middle. Now this time, we know all the little plastic shims
were in there right and the three wires were right.

Any ideas? Don and Cary 4107-130

[TomC]

If you are talking about the black box voltage regulator for the 50DN alternator, just get rid of it and buy a digital regulator-it is about the size of two deck of cards and regulates closer.  Good Luck, TomC

[RTS/Daytona]

Hi

I asume your system is 24 volt ??

then see--> http://www.ronthebusnut.com/detailDisp_10457699.html

But it sounds like your trouble is in the old junky 12 volt side of the OEM 24/12 regulator - That uses the "alternator R terminal"  which is 12 volts and offend used as tack input (14+ pulses per engine revolution)

The new reg will only control the 24 side - Most use a Vanner Equalizer to regulate the 12 volt side of the 24 volt system - cause the OEM reg was so bad at doing the 12 volt side (especially with the headlights on)

[Runcutter]

4107's are twelve volt, the next model (4108) went to twenty-four.  Cary, if you post your location in your profile (or, even better, in your signature line), many can direct you to local help.  I like Tom's idea about going digital, and I'd be interested in a source/part number for our files in case we have any problems in the future.

Arthur   (PD4107-1180)

[Cary and Don]

Well, the second problem has been solved.  After spending all evening trying to figure out why the new board fryed the reason was in it.  After comparing it to the old board, one of the solder joints on the new board had slipped in manufacture and was touching another route on the board.  We think it joined ground to positive.  That would sure make it burn.  Today we reinstalled the old board to make sure it didn't damage the generator or something else.  The generator is charging now and the tach works again.  It still has a little bouncing in the volt meter needle, the reason we where changing it, but at least no other damage was done.  Now to take that "new" board back and show it was defective. At least we aren't any worse off than when we started.

We would sure be interested in the digital unit also.  If anyone has the part number,  I think we would change the regulator out. Don and Cary 4107-130  Auburn, California

[Stan]

The common causes of varying voltage on the DN50 system is no load on the alternator, causing the regulator to cut in and cut out or bad connections in the wiring between the alternator, regulator and especially the ground terminal. If the field voltage is fed through a relay, you may have bad contacts in the relay (you mention tapping on a relay).