Installing a Jasco Alternator on the Bonanza A35
Hi Bryan,
 
Just finished converting the generator to the Jasco alternator on my A35 recently. I thought you might be interested in some insights I've learned during the process:
 
- The STC kit comes only with the alternator, voltage regulator, and instructions.  The installer must provide EVERYTHING else.
 
- Unless you have upgraded the generator previously, the primary feeder wiring must be replaced as the original 12GA wiring is insufficient to support a 50A electrical system (you'll need to go to 8GA, which interestingly is the same overall diameter due to insulation improvements over the years).
 
- Through much research I found circuit breaker P/N 700-092-50 (now mfr'd by Eaton Aerospace) is the exact same size as the OE P/N D-6751-1-XX breakers made by Kilxon, thus it fits perfectly with the existing buss bar.
 
- The voltage regulator is NOT the same size as the one for the generator, even though it uses the same style 3-point mounting.  This means the installer MUST build a mounting bracket for it to mount it in the same location.
 
- Because of the extra wiring for the new regulator a terminal strip is required.  I installed it on the regulator mounting bracket to minimize wire runs and make replacement easier.
 
- The firewall connector has plenty of extra pins available for the two 18GA wires that run through the firewall.  This is a solder-pin connector.
 
- The alternator requires a 2" diameter cooling duct whereas the generator is only 1" diameter, so make sure you have a place on the cooling plenum that can accommodate the larger duct.
 
- If you have the old prop governor that requires a T-drive for the tach cables you will likely have to reposition the T-drive due to the larger diameter of the alternator.  Watch where the cables are connected!  I mistakenly swapped drive ends causing my tach to run backwards on the first test run!
 
- Don't blindly trust the Beech wiring diagrams.  My bird wasn't wired anything close to how Beech said it was.  Good thing I'm an Avionics Engineer.
 
- Make sure you have space for two additional circuit breakers or fuses.  The generator used only one breaker; an auto-reset device probably located near the regulator.  The alternator requires a breaker for the regulator and another on the field line for the alternator. I used a switch/breaker for the field and a fuse for the regulator.
 
With the alternator, I am now able to run BOTH landing lights, the nav lights, beacon, and radios at 1000 rpm without discharging the battery.  The old "35A" generator couldn't even handle the radios alone at that speed.  This is a HUGE safety improvement at night.  Now I can actually be seen!! 
 
Regards,
 
Chris Nichols
A35 D-2127
Hi Bryan,

 There are two additional tidbits of information that will save someone else much aggravation:

 - The alternator comes with a new drive coupling (complete with the rubber isolation blocks). The instructions tell you to check for .005-,008-inch preload on the coupling assembly and proceed to explain how to do it through some esoteric babbling. I ended up calling Skytronics about how this check was supposed to be done (as well as the nut which I'll explain next) because I just couldn't figured out what they were trying to say. Turns out, they have made some manufacturing changes to the whole coupling assembly that obviate the need to check the preload any more. Nice of them to revise the paperwork accordingly...

 - Watch the drive coupling retaining nut size. This is the nut that holds the coupling assembly (and the drive gear) onto the alternator shaft. The one on my generator was a 3/8-24 thread fiber locknut, while the one needed by the alternator is a 5/16-24 thread castellated nut. Also, the washers used under the nuts are NOT standard AN, MS, etc. pieces. I actually thought my alternator had the wrong shaft on it (the other reason I ended up calling Skytronics) for awhile! After scouring my "favorite" toy store's catalog for a few hours more, I discovered a collection of generator attaching parts. I took the chance and brought the whole contraption to Aircraft Spruce to see if the nut they listed would work. Well, much to my relief slotted nut P/N 530412 (which is a nut/washer combination) is exactly what was needed to hold everything onto the alternator shaft. This little detail worried me because it was the show-stopper for the whole project. 

Chris Nichols
N8662A
A35 Bonanza