Diesel Alternator

[bassfid]

I have an old truck with a 130A Leese-Neville alt (integral reulator). When I purchaseded the truck, the alt. had no output. I replaced it with a new re-man unit. This new alt. also did not produce output, but included an instruction sheet that advised to "rev engine to at least 1200 RPM then momentarily touch (with a jumper wire) the pos (+) terminal to the regulator terminal." Upon doing this, the alt. began to charge. The problem is, when I shut down, and then re-start, the alt will not output unless I do the above mentioned procedure again. What gives?

 

[zeusfaber]

I wonder if the problem is in the truck wiring instead.

The alternator won't generate output until the regulator is powered up, and unless it initially gets power from outside, the regulator won't power up until the alternator is generating output - it's a sort of chicken and egg thing.

Normally, the regulator gets its startup power through the ignition light on the dash. If the bulb has gone, or the wiring has come adrift, then the alternator will stay stubbornly dead until either you flash battery power back past the rectifier (as you describe), or you get the machine running fast enough for the residual magnetism in the rotor to generate enough oomph in the stator to get the regulator going. This can take pretty high revs, but I've seen it work.

Alternatively, if the charge warning light is resolutely lit, you might consider checking for a short in the line between the light and the alternator.

Hope it's something as simple as this.

A.

 

[statorwinder]

This type of Alternator is self-energized by the residual magnetisun in the rotor.Over time this magnetisum loses its strength & has to be energized by a external power.Upon doing so it should last several months or maby even a year.


Some off-shore alternators coming into the US are not made of the best steel & loose this magnetism within a very short time.

Component parts are also being imported, these components are also not of the best of quality.

Other factors that influence the turn-on ,, rotor & stator WINDING air gap(not the stator laminations),, rotor coil distance from the pole claws.

i suggest you exchange this alternator for another one.If that does not cure your problem ,, check out the yellow pages under AUTOMOTIVE ELECTRICAL SERVICE or STARTERS & ALTERNATORN

George

 

[TChronos]

I didn't think the Leece Neville 130A was self exciting, but it sounds like it is. With a self-exciting alternator, you sometimes have to rev the engine quite high to get the alternator to get started.

You might try contacting Prestolite, as they manufacture Leece-Neville.

http://www.Prestolite.com