D17 S1 change to alternator

Use the pulley from the old gen. Will fit on new alt.    MACK

Be careful, the nose piece doesn't leave much room for one.

The alternator often is fatter than the generator and so won't fit as close to the block and with the generator pulley will require a longer fan belt. If a one wire alternator, it has to be turned fast to start charging, so a smaller pulley can solve both problems. When I got an alternator for my 4020, I was able to get an extension to its frame that made it fit the generator bracket. I still had to slot the bracket mounting holes to move it enough for the pulley to line up with the other pulleys on the engine.

Gerald J.

jaybmiller wrote: I opted for the 'newer' CS130 series alternator for my D-14s. Smaller but more power than the ancient 10SI series. Saved me having to hack the tin....FOUR times !!!! It might ba an option for you ?? Jay

^^ This

The CS130 is a better alternator. It should be readily available in most junk yards on smaller 1990s GM cars.

If you go the CS130 route there are one wire versions available too for around $100 or you can convert a used one to a one wire operation with a new one wire regulator for under $30. 

jaybmiller wrote: I've 'rescued' 4 of them from Cavaliers.Just be sure to get the connector at the same time ! At the parts store they're $20 !!! Jay

Generally there are two wires going to this connector. One for the (I)gnition and one for the (L)ight. Cut these two wires about a foot away from the alternator. You only need to use the wire that goes to the ignition unless you also want to use an idiot light. The CS130 (or 144 which is the same except for a cooling fan) uses internal sensing. You don't need to hook up a sense wire.

I'm going to use all 3 wires and put in an idiot light. Figured why not it can't hurt.
The wire from the alternator all the way to the ammeter makes me nervous - should I put a breaker or fuse in line? I found I had a push button reset 30 amp breaker, but I don't think that would be big enough.
I pulled the fuel tank and ripped out all the old wiring, going to start from scratch. New ammeter, oil pressure gage, rewire my new front and rear lights. Fix that valve cover leak too. Tie down all the wirew with rubber lined P clamps. Wires from the alternator to the valve cover are kind of hanging in space, so I'll take a bolt out of the back of the water pump and put a P clamp on there as well.
cheers,
Creek

Creek,
Be careful this is the way full restorations start!
You should be real happy with the conversion!
Regards,
 Chris

Creek: Fusible links do more to protect the wiring when the alternator shorts out and the battery attempts to discharge through the alternator wiring. Ford trucks (maybe cars too - I'm less familiar with car wiring)use several #14 AWG wires tied in parallel. Four 6 inch pieces of #14 tied in parallel and insulated at the ends with shrink tubing should do the trick. Personally I'm more fond of an accurate voltmeter when using an alternator, but to each their own.

Dan73 wrote: I like a volt meter because you can see the battery voltage before you start the motor and know if you have a battery issue. Amp meters only tell me that the generator is working but not if the battery is holding a charge the next morning.

If your battery happens to have a shorted cell the ammeter is going to tell you that your generator is really doing its job well. As Dan said, the voltmeter will tell you the next morning that all is not well.

Well got the alternator mounted and everything put back together.

I also wired in an idiot light to go with the 60 amp ammeter.


Started it up and everything seems to work, but the red light comes on until nearly full throttle, then it goes out and the ammeter kicks over to charge. I hooked up the 3 wire Delco 10SI with the field and sensor wires going back to the dash, but must not be enough juice to get it going at idle. Battery voltage is 14 when charging. Not a big deal.

I also hooked up my timing light as it now works with the negative ground. Holy crikey that hole in the frame is small. I'll have find the F mark manually and paint it.
Just for grins I hooked up my old dwell tach as well. The tach part just pegs when I switch it to 0-1200 or 0-6000, I dunno whats up with that. Dwell says 40 deg, which I think means the points are set a bit tight - it's been like 30 years since I used a dwell meter so things are a bit cloudy.
My new oil pressure gage sadly reads even lower pressure than the old original one, which is really scary. I'm going to get a regular pressure gage and hook it into the line at the filter and see what it reads. Prob can take the one of my G or C and try it.
Must have crimped the capillary tube on the water temp gage when I put it in tubing with all the wiring, that is not working either, have to get a new one.
cheers,

Creek

Hey this is a timely post as I was going to ask some alternator questions because my father is thinking of doing this on his John Deere 50. 
1.  Should one replace the ammeter?  in other words if the old ammeter only goes to 20 amp will it just peg out for a while if the alternator is putting out more amperage or will it cause an unsafe condition (such as heat and fire?)  I realize a voltmeter may be better, but am just asking.
2.  Where did you decide to hook up the sensor wire?  I see a lot of people just hook it to the output wire of the alternator but that kind of defeats the purpose.  Would probably work ok for old tractor use though.
3.  Where did you hook up the exciter wire?  It could probably just go to the + terminal of the coil if one didn't want hook up an idiot light on the dash.  What size diode does one use on the exciter wire?  Where does one buy the diode?  I understand it's needed otherwise the engine may not shut off when turning off the key.  Also I read there needs to be a resistor in the exciter wire.  Why is that?  I have also read that an idiot light serves as an adequate resistor. 

The ammeter range needs to match the alternator capability so it has an adequate conductor inside. 60-0-60 is probably enough. The wire from the alternator to the ammeter and ammeter to the battery (usually connected at the starter solenoid or switch but can be at the battery post) should be increased to at least 8 gauge. I have a 10 gauge silicone insulated wire on my 4020. The silicone can handle the heat and with the voltage sample wire connected to the alternator post it limits charging current to about 35 amps according to the ammeter I added. Compared to the 20 amps of the original generator I'm happy with twice as fast charging. Its easier on the battery than hitting it with 60 amps charging but means I have to be a little more patient.

A voltmeter is definitely easier to wire, but depending on where its wired and how much resolution and precision it has it can give misleading information. The ammeter shows actual battery current while the volt meter shows voltage somewhere in the wiring between the alternator and the battery and battery loads. To truly show battery condition the voltmeter should be connected to the battery posts with separate connections from those used to load and charge the battery. But then it will run the battery down unless connected with a relay that disconnects it when the engine isn't running. Even in that case it needs better than .02 volts precision and display resolution. Most automotive shop volt meters don't have nearly that precision and resolution. When the regulator on the battery works right holding the charging voltage to 14.2 volts for a starting battery the battery current WILL taper to zero showing the battery is fully charged. That is an indirect indication the battery voltage has risen to 14.2 volts that could be seen on a precision voltmeter. I've tried voltmeter and ammeter lab quality in a car long ago and even with both the ammeter was way more informative.

The diode, resistor, or light in the excitation wire limits current fed back to the ignition system to prevent spark from that feed back current. Any of the three works. There are Radio Shack stores some places around the country. Look at http://www.radioshack.com for details. On line http://www.mouser.com and http://www.digikey.com have at least 100 different suitable diodes and probably a mere million in stock at decent prices, but shipping costs at least $5 though a dozen diodes could be mailed with one first class postage stamp. Neither has a minimum order price. Radio Shack sells on line these days too. Then there is epay. Any diode in the 1N4000 to 1N4007 family of 1 amp diodes or 1N5404 3 amp diode is adequate. The sturdier diode will stand up to vibration better because of sturdier leads. 50 volts is adequate PIV (Peak Inverse Voltage) and sellers in China will ship 100 diodes in that 1N4000 family for 99 cents or better. Might take a week or two to arrive and there's 99 left over.

Gerald J.

6 AWG is ideal, but costly and can be difficult to work with. Unless you are drawing a constant load from the alternator you can get by with something as small as #10. If the battery is very discharged rge smaller wire will self-limit the current anyway. As the battery charges the load from the alternator decreases, causing the charge voltage at the battery to rise.