Hello Everyone I recently bought a old tractor loader MF50a it dosnt have the back hoe on it. I am having some issues with wiring. I replaced the alternator on it since it was making noise and noticed that the amp meter wasnt working either. So i looked at the original wiring for the tractor but its for the old system with a generator and a voltage regulator. My alternator is the AC delco with the built in regulator and I just cant seem to understand how to wire it. I need some help please. It seems like the wiring was modified after all the years but done not correctly. Thanks
I would bypass the amp meter, or replace it with a volt meter, an amp meter is appropriate for a generator, a voltmeter is good enough for an alternator, or even just an idiot light is fine too. Your big wire should go from the hot terminal on the solenoid directly to the alternator big nut terminal B+, one of the small spade terminals goes to the ignition switch, and the other one can be hooked directly to the big nut terminal B+ on a tractor with virtually no electrical demand. Look up the wiring diagrams for the alternator, it's simple if you can find the original generator regulator wire that is switched from the ignition switch. You CAN run the alternator off the Ammeter, but it's not worth it to me, it will do fine for a simple tractor if you want it to stay more original.
Steven; go to post #39 in this thread. The entire discussion explains every detail about that set-up. HeavyEquipmentForums
Black wire comes from ignition
Looks like you need a nut on that post, John.
Steven ; Can you post a better picture of your wires on the alternator ? We need to see how they are connected to the alternator. If you read that thread I posted the link to, you find that those alternators can be wired in different configurations.
I was taking this guy apart to remove the engine which had a bent crank I like to take pictures when t take stuff apart be I find the older I get the more I forget
So John Hofer probably already took the nut and the big wire off that terminal. That shows the simplest way to hook up a delco alternator. IF yours is a one wire alternator, then you don't need the two small spade terminals hooked up to anything.
So thanks guys gor the answer very appricate it. I went to the massey dealer the other day and they also provided some.help but its still not clear for me. They gave me these wiring diagrams and said this should help. Now i am just more confused. I removed the voltage regulator since they told me.it should be intergrated in the alternator.
Thanks it seems to be like the wiring diagram the tractor dealer gave me. But my alternator they told me should have a built in regulator in it.
The wiring diagram for you machine shows an externally regulated alternator. You bought a GM replacement alternator that is internally regulated. Do you want an ammeter? if not the wiring is much simpler. I would wire an idiot light and no ammeter if I were in your shoes. This is very simple to make it charge. Rewiring some things to get them working correctly will need to be done according to the way the original system is wired.
the simplest way to make it work is to hook it up like John Hoffer's pic, which is the same as your first pic, you don't need a diode because you have a diesel, right? Even simpler, run the big wire directly to the starter solenoid battery connection, bypassing the ammeter. If you have a pressure gauge instead of an ignition switch, you'll have to have it running to see what is switched by the pressure switch to give you a hot for the alternator feed. Or short across the switch to see what wire to use for your feed. This is for the spade terminal that is not hooked to the big threaded terminal.
I think the confusion comes from the generator and the alternator. You have the drawings for both, you need to decide which one you want to use. The generator needs a voltage regulator. The alternator does not. The simplest to make work is the GM alternator.
Umm, Did you connect the wires onto the replacement alternator the same way they were on the old one that was making noise ? This is why I was hoping you would post a picture of the new alternator and the connections on it.
Looks like his original setup had an alternator, not a generator, that was externally regulated. Some wiring changes will need to be made to accommodate the GM alternator.
So I got around to starting the wiring. It seems like the volt meter dosnt light up only when I start it its getting voltage. So I installed the new pressure switch but not sure which connecting terminal the wiring goes to. One says nc and the other is c . Here are some pictures. I installed the diaode like it says towards the alternator on the #1 terminal. So if you have any ideas please let me know. Thanks again for all the posts guys.
the alternator looks good, the starter looks good, I can't see what's between them, or the rest of the connections, you'll have to compare to the wiring diagrams, or show all the connections and label the wires to get any more specific advice. Do you have a key switch? or just a start push switch? The pressure switch, if it has three terminals, they'll be NC/normally closed, C/common, and NO/normally open, right? Don't use the NC terminal, use the other two to turn on your alternator and volt meter when the oil pressure rises, and off normally, that is when there is no pressure. Unless your voltmeter comes on with the engine off, and then doesn't work when running, then their definition of normal is different than mine.
So the pressure switch has only 2x connections on the back of it 1- NC 2- C . As for the volt meter it turns on when I am turing the key to start it its a 1/4 turn then it returns back to its position.
I believe you are making this harder than it needs to be. A voltmeter only needs to see a system ground on 1 side and system positive voltage on the other side. Ground the negative terminal of the voltmeter, the connect the positive from the voltmeter to the ignition side of your ignition switch. This way you will only show voltage when the ignition is on. If you read voltage on your meter when the key is off, then you have the positive side of the meter hooked into the supply side of your battery power which will run your battery dead when sitting over a period of time. What is the pressure switch for?
ok that sounds more simple. For the pressure switch its a diesel engine so its used to close the contact when the motor is running so that the system knows when to charge is what they told me.
You don’t need a pressure switch. The Delco SE alternator turns itself on at a specific speed and turns itself off when you stop the engine.
Ah ok that sounds simpler then. Thanks for that info
Vetech, ** used a pressure switch to turn the electronics on and off, like the second wiring diagram. If your key switch is only for starting, it doesn't have an IGN, and ACC terminal, then you'll need the pressure switch or some other switch to turn the electronics on and off. You don't need any diode, that's for a gas engine, or one with an electric shut off fuel injection pump, you have a lever shut off pump, right? That voltage gauge wiring looks right, you have the instrument light wired up, does that work? I'm assuming you have one wire jumped from there to another gauge? that's the two medium size red wires on one terminal? Again, it looks OK but I can't see any of where the wires go or what is wrong that the volt gauge doesn't work. Edit, even with a one wire alternator, you will need some way to switch the gauges on and off. ignition switch or pressure switch. this might not be a self energized one wire alternator, the voltage regulator is inside the alternator, and it will run the way you have it hooked up. Did you specifically buy a "one wire alternator" or "Self excited"? then it should have come with some instruction, even if they're redundantly simple. I've never understood if all internally regulated Delco's will self excite if run fast enough, but it won't run fast enough on this old ** to start so it must be hooked up if not "one wire". Does your switch have continuity with the engine off? how about with it running? is this a ** part number switch, or one off ebay that fits?
Yeah I should have looked at the diagram. The last MF50 I saw had a standard ignition switch but may not have been factory. I’m not so sure the OP shouldn’t remove all the wiring that he has done and start over. Looks like there could be some backfeeds in that mess. It would be nice to have some clarification on what is actually being worked with on the tractor......or did I miss that? A pic of the back of the ignition switch would be helpful.
It's not that bad, all you have on that wiring diagram is a fuel gauge, voltage gauge, and the alternator feed. Three things that need to be switched on and off at the same time, with either an ignition switch or pressure switch. The starter switch is separate, and the lights are separate, if any lights.
Are the two fuses (#30) that are shown in the schematic still intact in the charge circuit ? I would be eliminating them if they are.
By the look of his alternator in a pic....he doesn’t have an SE.
Exactly, Vetech ! That is why I requested that he post a close up photo of the wires on the alternator. If the original alternator is on there, then there is problem.
That’s why I suggested to start over. It looks like the wiring is all over the place and like Delmer said.......we can’t see where everything is running and what is connected or not.
So from what I understand you guys are asking if its i have a lever shut off pump yes I do. The switch is an original part. It dosnt have continui when its off. The gauges lite up when starting but not when the switch returns to its off position. So I believe the wires must be reveresed. The alternator is from a parts supplier and no install instructions came with it. What I am.wiring is just the volt meter fuel gauge thats it. Here is a pic of the alternator connection. Also if I don't need the pressure switch then I can eliminate it in the wiring. Thanks guys for you feedback
It sounds as if your gauges are on the start post of the ignition switch. That would explain why they go dead when you release the key to stop the stater from turning. If you replaced the ammeter with a volt-meter it has to be wired differently as was mentioned before. Personally I would much prefer to have an ammeter that shows current flow. I always liked an idiot light along with an ammeter. One of it's functions is to give an alert when the charging system goes into a discharging condition. If you read post #23 in the link I posted you will be able to see that I have had a little experience with what you are doing. Thie image is my own alternator.It should look familiar to you.
Well that’s not an SE alternator. That one you have should have the external voltage regulator as your field power will run about 7 volts.
Good observation Vetech ! I have never seen that style. I was wondering why there are two slots in the back of his.
It’s a shame I can’t see this machine in person. Give me an SE alternator and some wiring and this job is done in 20 minutes.
Steven, you're going to have to figure out what wires are hooked up wrong because only you have access to this. if you want any useful help, we need to see all the components and have the wires labeled. We can't tell much from a picture of a bunch of red wires. It does sound like your voltage gauge (and possibly alternator excite and fuel gauge?) are hooked to the start switch? do you have only two terminals on your start switch? that's possible because the "ignition" is switched with the PRESSURE SWITCH, they do this so you don't turn the engine off and forget to turn off the ignition and drain the battery. Get the voltmeter and fuel gauge working, and power to the alternator with the engine running, and if the voltage doesn't get above 13, then we'll figure out the alternator.
Ok perfect so I will get those gauges to be powered up and my start switch is just a spring return key. I am just not sure where to connect the pressure switch too ? If you guys can sketch a drawing that would be very appricated or of you have one that is close to it. Also dose this mean that my alternator need to have a voltage regulator from your post Tinkerer
From what I see in your photo of your alt wiring it appears you have it wired like mine. If it is then you need to have an AC Delco SE alternator. It has built in regulator. They can be purchased in any auto parts stores, a rebuilt one for about $35.00. The pressure switch can be unplugged and then connect the two wires together. It is impossible to tell you how to wire it to make it functional after someone has altered the oem wiring configuration. Your schematic only shows where the green wire on the pressure switch goes (the starter solenoid). The other one disappears in the loom. I would think it had to go to a post on the OEM starter switch.
Figure 7-8 is what you want to copy for the start switch wiring. The fuel gauge, volt gauge and alternator feed will be on the same parallel circuit, fed power from the pressure switch. You won't have a voltage regulator, remove and bypass it if there's one there, the voltage regulator is inside that alternator, but it does need switched power to start up. The wiring on your alternator looks correct, and the wiring on the gauges looks correct, but I can't see the other ends, you'll have to make sure they match Figure 7-8, except for the changes. Don't get hung up on what wires go to what terminals, you have to be able to think about the wires as what's connected together, and what switches turn on what. In this case you need power, that will come from the wire that went to the old ammeter, or the light switch, or the start switch. If your start switch works,then that's fine. You need to run power to one side of the pressure switch, and run the other side to feed power to the gauges and the alternator small spade terminal. I am disagreeing with Tinkerer here, a self excited alternator only needs one big wire hooked up to the threaded terminal, a standard delco alternator needs to be hooked up like all the ones in the pictures (NOT the old style in the diagram).
Yes I agree with Delmer, and am disagreeing with Tinkerer. The alternator you show has an internal regulator, just not a self-exciting one. All that alternator needs is the wire off the post to the battery hot, either at the starter or battery, the red wire from the plug to the post just like it is, and switched power to the white wire on the plug. You will have to have some kind of switch sending power to your gauges and that white wire. If you don't have a switch, they will kill your battery. The + side of the voltmeter needs to go to switched power, and the - to ground.
I could draw you a simple pic that would show the minimum wiring needed, but I don't know how to post it.
AC Delco self exciting alternators can be wired in different configurations. The one I use and prefer is one of them. Confusion seems to surface when someone refers to a one wire set-up . There is a true one wire configuration no doubt about it. A Google image search will show the different ways the Delco alternator can be wired. I used that search many years ago to figure out how to create the configuration I prefer. I guess mine could be called a three wire set-up.
I guess the disagreement is that I would call only a one wire alternator "self excited", any other Delco alternator would be "internal regulated" and need at least one SWITCHED excite wire. Maybe Delco has been calling them "self excited" all along and Mitch and I are wrong. I will try to use only "one wire" or "internal regulator"
Delmer; You and Mitch are not wrong in any way in my opinion. I copied the following info. from a website. I have been aware of the three configurations for a lot of years. Those three configurations is what I causes so much confusion for me, because when I see someone wanting help it is hard to know which of the three they have. That is why I always ask to see a picture of the alternator terminals with the wires on them. I'm not trying to be know it all by any means. Just trying to help members understand how a delco alternator can be installed in different ways. ----------------------------------------------------------------------------------------------------------------- One-wire Alternator: Is another name for the Self-Exciting Alternator . You only need to connect the battery wire (one-wire). The alternator turns on the voltage regulator when the engine starts turning the alternator. Two-wire Alternator: Most standard and all self-exciting regulator alternators will work using the two wire setup. Two wire means that you use the main battery wire to the back of the alternator and also ignition wire to the #1 terminal to activate the alternator. With this setup the alternator starts charging as soon as the engine is running Three-wire Alternator: This setup uses a battery wire, ignition/warning light wire and voltage sensing wire, Three wires. Voltage sensing is used when you want the alternator to read voltage at some point other than the battery. Or the battery wiring is such that the battery is a long distance from the alternator.
Yep, the 1-wire is what I was calling self-excited, and the 2-wire is what I was calling standard, or internal regulator. I am glad you posted that because I understand the 3-wire better now. On a side note, I seldom use the $35 1-wire from the parts stores if I can use the 2-wire setup with a manual switch or an oil pressure switch. I started having trouble with those regulators sticking and killing batteries. I don't see that with the heavy duty 1-wire alternators. BTW, what website was that? I'd like to go see what else they have for me to learn.
And on tractors or heavy equipment with very little electrical draw, we usually tie the third wire to the battery wire, like in all the pictures and diagrams shown. This effectively makes it a two wire alternator, which we get away with as long as the main cable is in good shape. The voltage regulator for one of these delco's is about $5-10 and can be swapped on the machine in very little time. That regulator is the only difference between one, two or three wire, and even some "ONE WIRE" regulators will have the two terminals, even though it will work without them hooked up. confusion never ends.
https://alternatorparts.com/what-is-a-self-exciting-alternator.html I change out the standard regulator to a self exciting one so that it will begin to charge as soon as I start the motor. No need to speed it up to get it to charge with a three wire set-up. They can be purchased at NAPA. here is one one ebay ---> https://www.ebay.com/itm/Delco-10SI...405973&hash=item3d693084f5:g:gaIAAOSw~K9dyYfo For sure Delmer, it makes it very hard to help members that have butchered wiring and are trying to installor fix a delco alternator.
Hey Guys So for the wiring its all good now. I connected it like the delco drawing and fused it as well as added the volt meter on it and its charging now. Some wires were not connected the way you told me so after reviewing the wires one by one now it work good. Thanks all for the help!!