stump jumper Posted November 12, 2021 Share Posted November 12, 2021 Does anyone know how to convert the existing external regulated alternator in a 1966-67 scout 800 to a one wire internally regulated alternator? Quote Link to comment Share on other sites More sharing options...
Administrators Moses Ludel Posted November 12, 2021 Administrators Share Posted November 12, 2021 Hi, stump jumper...Always good to know that the early generation Scout 80s and 800s are still in service. Which engine do you have? Scout Parts at scoutparts.com shows a rebuilt alternator for 1961-71 models with no mention of any required brackets. This may be a simpler 1-wire (GM style) hookup but needs clarification and confirmation. Use the search box at the site with the keyword "alternator": https://scoutparts.com/ I have been familiar with these folks for many decades now, they would also be a knowledgeable resource: https://www.superscoutspecialists.com/ Due to their hook-up simplicity, the GM single wire alternators are popular for street rods and generator-to-alternator conversions. These units have a rectifier bridge and no external regulator. They generally use an exciter wire and higher amp gauge charge line. What is most important with any of these conversions is the wiring. You are stepping up in amperage, especially the amp output at an idle, which is why an alternator is so much better than a traditional D.C. generator. Proper wire gauge on the charge lead to the junction or battery is crucial. Depending upon load and length, you need to step up in gauge as necessary. Make sure high amp current cannot flow through any lower amperage (lighter gauge) wire. If you change to a "universal" single wire alternator, make sure you have a wiring diagram with recommended wire sizing. I have gone as far as 1/0 gauge charge and ground wiring when running a 140 amp alternator that powers up an onboard frequency welder. The two links/resources can likely answer questions about brackets. Otherwise, you will need to fabricate an alternator mounting bracket and possibly a belt adjuster arm. Alignment of the pulleys and the correct belt size is essential. None of this is rocket science. It can be worked through. Let us know how you resolve the alternator installation... Moses Quote Link to comment Share on other sites More sharing options...
stump jumper Posted January 17, 2022 Author Share Posted January 17, 2022 I found an alternator that fits perfectly (one wire) I realize that the positive terminal can be wired directly to the battery positive post and the ground on the back of the alternator must be grounded to the motor. None of the factory gauges or headlights etc. have been used or have worked for 18 years. I have plow lights fused ,switched and wired directly to the battery. This scout is used only as a snow plow scout for my 400' driveway in the winter . All I require is for it to start-and charge the battery. Question-The large factory wire feeding off of the original alternator --what do I do with that? Do I run a new wire directly to the battery and tape off the origional wire or do I put both wires on the positive terminal on the back of the alternator? Quote Link to comment Share on other sites More sharing options...
Administrators Moses Ludel Posted January 18, 2022 Administrators Share Posted January 18, 2022 Hi, stump jumper...Glad you found the right fitting alternator. Did the original heavy alternator wire terminate at the battery? At the starter solenoid? Or at the battery cable post terminal? If you can share, I will make a suggestion. The single wire alternator typically feeds the battery lead to the battery via a fusible link wire. If you do end up installing a new wire from the alternator to the battery, make sure you install a fusible link (higher amperage rated for the alternator output) on that wire. Fusible links are available with pigtails and connectors for this purpose. Here's the least expensive example I could find. These can get pricey: https://www.amazon.com/Bussmann-BP-FLD-140-RP-Fusible-Terminal/dp/B009WQPKVW/ref=sr_1_6 Here's another approach, you'll get the idea: https://www.amazon.com/ACDelco-6ST44-Professional-Positive-Battery/dp/B008BZSH88/ref=sr_1_6 Fusible links are available for different amperage ratings. Not sure what your new alternator puts out. You need to protect the electrical system and wiring from a meltdown or worse. Please share the alternator amperage rating. I can make a suggestion from there about wire gauge, terminal ends and so forth. Moses Quote Link to comment Share on other sites More sharing options...
stump jumper Posted January 19, 2022 Author Share Posted January 19, 2022 The big positive(red) cable goes directly from the battery to the starter solenoid. The wire feeding power from the back of the alternator goes directly through the firewall to one side of the the ammeter gauge. It then continues from the other side of the ammeter gauge back to the starter solenoid and it is connected to the same solenoid stud as the big red wire from the battery. On the back of the factory alternator there are the standard r+f posts.On scouts (I have had 3) only the r wire is used and goes to the r terminal of the harness that plugs into the external regulator. I hope this info helps Quote Link to comment Share on other sites More sharing options...
stump jumper Posted January 19, 2022 Author Share Posted January 19, 2022 Sorry-the original alternator is a approx 90 amp rebuilt. The new one wire is about 60 amps which should be sufficient to charge the battery.The scout is used only to plow my driveway and is not licensed nor has been for the 18 years that I have had it. I never use the factory lights and the plow is belt driven with a hydraulic pump that operates off of the motor. The only lights that I ever use are two hood mounted plow lights that are fed directly off of the positive battery post through a fuse link and switch that is mounted on the dash in the cab. Quote Link to comment Share on other sites More sharing options...
Administrators Moses Ludel Posted January 20, 2022 Administrators Share Posted January 20, 2022 stump jumper...So, if the alternator charge feed went to the ammeter then to the shared battery stud at the starter solenoid, you can route your new alternator's charge lead the same way. Run the charge lead to the ammeter, and you will continue to get an amp/charge reading. Leave the other ammeter lead as it is, feeding current to the starter solenoid/battery cable. Make certain the alternator is grounded properly to the engine or battery negative. If grounded to the engine, make sure the engine to battery ground circuit is ample. Battery cable gauge wire works best. I would still use something like the Bussmann inline fuse on the charge lead from the alternator to the ammeter. A fuse around 80 amps would be high enough amperage if your new alternator's output is 60 or so amps. This would add a level of safety in case the alternator or wiring shorts to ground. Make sense? As for 60 amps, in the early days of alternators, 60 amps was a major gain over the D.C. brush-type generators that they replaced. I worked on a fleet of 1949-61 light and medium duty trucks, every one equipped with a generator. They put out low amps at an idle. A peak of 40 amps was considered a heavy-duty, high output generator. The most significant gain with alternators was the ability to charge well at an idle and lower engine speeds. Moses Quote Link to comment Share on other sites More sharing options...
stump jumper Posted January 20, 2022 Author Share Posted January 20, 2022 Moses-Thank you! That will save me a whole bunch of trouble.I will try that. So I should be able to just hook up the existing large hot wire to the new alternator,however do I un plug the existing external regulator? Quote Link to comment Share on other sites More sharing options...
Administrators Moses Ludel Posted January 22, 2022 Administrators Share Posted January 22, 2022 stump jumper...To clarify, how many wire terminals does the new alternator have? I'm unclear what the design and original application is. Can you clarify? Some GM alternators use a rectifier bridge with no external regulator. (That's what makes them popular with hobby cars and street rods.) Did you get a wiring schematic with the new retrofit alternator? What is the alternator core source? I'd like to know the alternator's intended use and see a wiring diagram. If there is only one heavy stud terminal plus a Key-On exciter wire terminal, we can discuss the wiring layout in more detail. It would be unlikely that the heavy lead keeps the alternator "hot" at all times. Some pictures of the new/replacement alternator would be helpful. Moses Quote Link to comment Share on other sites More sharing options...
stump jumper Posted January 23, 2022 Author Share Posted January 23, 2022 The new alternator is a one wire . It has the hot output terminal and a ground terminal .There is a small stud that has a rubber cover that is marked "r". It is internally regulated. The origional altenator is a delco remy and has a hot output terminal ,and the standard r+ f terminal . The original has a delco external regulator mounted on the radiator support. If I run ,as you suggested, the output (+) wire directly to the ammeter and from there to the starter solenoid I might as well use the original wire from the back of the alternator because that is exactly the same. But if I do that then I am assuming that I have to disable the original external regulator . The entire idea of this swap was to bypass all of the stuff with the exception of the ignition switch )so it will still start with the key.I do not need any gauges or headlights as I mentioned before. That is why I was hoping to run the output from the rear of the one wire directly to the positive post on the battery. I will try to get some photos to post.. Quote Link to comment Share on other sites More sharing options...
Administrators Moses Ludel Posted January 24, 2022 Administrators Share Posted January 24, 2022 stump jumper...This does go back to my original information: the new alternator does not need an external regulator or exciter wire. Apparently, the one wire functions as an exciter and charge lead. The issue is whether the lead is "dead" when the alternator is not spinning. You can test this easily enough by checking for voltage bleed from that lead when the engine is not running. I did some homework and believe this is the confirmation we need. If this is your new alternator configuration, my original wiring suggestion will work: "Tuff Stuff's OEM or one-wire alternators are usable in both one-wire and three-wire installations. With a one-wire install, simply connect the charge wire from to alternator battery post (left) to the battery. Tuff Stuff does recommend upgrading the charge wire to a larger gauge (smaller number), as the factory wiring might not be capable of carrying the extra amperes without melting. If you plan to use the factory three-wire installation, install the charge wire to the post, then remove the black plug (right) and connect your factory two-wire connector." This information came from a Chevrolet enthusiast site. Below is the link to the full coverage. Read it. If this is your alternator, you can route the single charge lead from the alternator to the ammeter, then the ammeter to the starter solenoid (battery junction). Again, I would use the Bussman or similar fuse on this charge lead for safety. Test it. If this can be accomplished with existing wire, great. (Do not route through the OEM external regulator.) Make sure the alternator to ammeter and ammeter to solenoid wire gauge can handle the amperage output of the new alternator. Step up in gauge if necessary: https://www.chevyhardcore.com/tech-stories/ignition-electronics-efi/alternator-selection-one-three-wire/ Regarding wire gauge, heavier will not complicate the charge flow. On project vehicles for magazines, my high output systems for an onboard frequency welder powered by the alternator would run 1/0 cable at the grounds and the battery hot cables. Be aware that ground cable from battery-to-frame-to-body-to-engine must be as heavy gauge as the positive battery cable lead. The alternator ground is part of the overall ground circuit. Make sure the alternator ground is sufficient. Many OEM systems attach the battery negative cable directly to the alternator or alternator bracket then use a heavy ground from engine-to-frame plus an engine to body ground strap. Let us know how this works out... Moses Quote Link to comment Share on other sites More sharing options...
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