Main Alt and Spline Alt Alternative?

[rv7charlie]

Email me at mcsophie@gmail.com & I'll send you the old AEC pdf showing the circuit, and the parts list/schematic pdf for the OV module.

Troll ebay & Amazon for 12V automotive relays (the cube shaped ones that are everywhere in modern cars) You can get them up to around 100 amps. Be aware that the larger ones use bigger Faston terminals than the 'standard' 1/4". Or you can just use a regular master solenoid, but it'll be a lot heavier & consume more holding current.

[lr172]

Originally Posted by BMC_Dave

Great info on alternator regulation, thanks Larry. My only aversion to going cheap externally regulated is that ND alts seem to have a good reliability history. I found this one: https://www.oreillyauto.com/detail/b.../4602876?pos=0 which is a Hitachi rebuild, 60A externally regulated. If I were to be less conservative on my cruise loads I could just make 50A work if the alt you're referencing is a better quality.

Charlie: By saying "early IR" do you mean it's not as much an issue anymore? I would want a way to periodically test the function of the secondary alt without hurting the primary. After much research it sounds like the main failure of alternators is the internal regulator, hence my wanting to get away from it.

The alternator I used (from an 80's Honda spec) is an ND, so good quality. The "cheap part" comes from the rebuild. However, most rebuilds on externally regulated alternators only include a shaft polish, bearings and brushes; So not a big impact by going cheap. I think they just toss em if the stator or armature has problmes. Mine has worked faithfully for 600 hours. The big issue with "cheap" is the internal VR's, which are the most common cause of alternator failures, excluding the plane power which has many other flaws.

[BMC_Dave]

Originally Posted by lr172

The alternator I used (from an 80's Honda spec) is an ND, so good quality. The "cheap part" comes from the rebuild. However, most rebuilds on externally regulated alternators only include a shaft polish, bearings and brushes; So not a big impact by going cheap. I think they just toss em if the stator or armature has problmes. Mine has worked faithfully for 600 hours. The big issue with "cheap" is the internal VR's, which are the most common cause of alternator failures, excluding the plane power which has many other flaws.

Might you have a part number or link, the Lester was made by Remy and didn?t look like a ND.

[lr172]

Originally Posted by BMC_Dave

Might you have a part number or link, the Lester was made by Remy and didn’t look like a ND.

I used the Lester# 14158. The lester number is a 5 digit number used by the aftermarket for identifying alternator configurations; It does not denote an alt manufactured by Lester. The 14158 is an old style ND alternator, producing 50 amps and externally regulated. In my research, I could not find anything with greater output that fit in that early generation ND case size. You went up in physical size with more capacity. I am sure modern alternators produce more power in a smaller case, but I didn't realize there was a trend back to ER and assumed they were all IR and didn't want to modify.

I prefer using an alternator with the proper fan orientation, as it does make a diffeerence with external fans. Charlie may be right about internal fans, but with the externals it makes a difference. How much I don't know.

Larry

[BMC_Dave]

Ah, thanks Larry.

So I found this: http://www.aeroelectric.com/articles...Conversion.pdf

And that seems really easy, if I understand correctly. The only part that isn't clear is the re-wiring of the regulator. From looking at alternator schematics it really seems we're just tying one brush to the case+ground and the other brush to the field terminal right? The author says this works fine with a regular VR166 regulator. I can't determine if this method results in a positive or negative field polarity, but if I can get by with just a VR166 I'd be happy.

[lr172]

Originally Posted by BMC_Dave

Ah, thanks Larry.

So I found this: http://www.aeroelectric.com/articles...Conversion.pdf

And that seems really easy, if I understand correctly. The only part that isn't clear is the re-wiring of the regulator. From looking at alternator schematics it really seems we're just tying one brush to the case+ground and the other brush to the field terminal right? The author says this works fine with a regular VR166 regulator. I can't determine if this method results in a positive or negative field polarity, but if I can get by with just a VR166 I'd be happy.

You need to know which brush is negative and which is positive. As I mentioned, some alternator's internal regulators feed POS and others feed NEG. You need to either know which style is used or be able to tell from looking at the alternator layout. You CANNOT assume that the feed from the VR to the brush is one or the other, as they are not standard.

If I remember correctly, if one brush is tied to the frame, you can assume the VR is feeding positive. However, if the VR feeds NEG, it becomes very difficult to determine polarity without knowing the pinouts of the VR, unless you find one brush tied to the B lead. If memory serves correctly, the ND's use a NEG VR feed.

You can probably assume all ND's are the same and therefore follow someone's instructions for that type of alternator, but not instructions for a different manufacturers alternator, unless you confirm it uses the same VR polarity scheme.


Larry

[BMC_Dave]

Right on. I went ahead and picked up a ND IR alt and have started on the external regulator mod per the instructions. Going this route it looks like I can get down to a single B&C spline alt and 2 OV modules. Heck of a lot better than spending $2.5k+ on a whole package

[BMC_Dave]

Well that worked out well Tested the alternator with a jump starter, figured it was designed to be loaded and recharged, and a drill. Super sophisticated setup as you can clearly see. VR166 voltage regulator from O'Reilly's. I could feel the alternator kick on when it got up to speed, but my drill could just barely get there. I did end up re-soldering the bypass contacts for a better connection.

I am curious though, testing the alternator diodes I get 0.477V drop. Can anyone confirm this is good for alternator diodes? I can't find any information on what the ideal value should be.

[rv7charlie]

Depends on the array design & where you're measuring. It's not just one diode. If it's a new alternator, it's very unlikely you have a problem.

https://www.google.com/search?q=alte...w=1680&bih=946

Charlie

[BMC_Dave]

Originally Posted by rv7charlie

Depends on the array design & where you're measuring. It's not just one diode. If it's a new alternator, it's very unlikely you have a problem.

https://www.google.com/search?q=alte...w=1680&bih=946

Charlie

Oh yeah I don't think there's an issue. I was directly measuring each diode and they were all the same. I was just wondering what the normal value should be, a cursory Google couldn't even identify the type of diodes used.