Hi folks!! I added a great-running old Ford 4500 tractor to my collection last week, and am getting some minor issues cleared up. I started with a fresh coat of Case Power Tan to match my fleet, Before/after below: As you can see, the tires, hoses, gannon, and cutting edges are all brand new. As I start to get everything up to snuff, I'm finding a lot of parts are NLA (like the factory decals and grill assembly), so I am fabricating a lot of those cosmetic parts. The factory instrument cluster was missing when I took delivery of the machine , so I made a dash out of aluminum diamond plate (looks better than the cheap factory cluster, IMO). I used mechanical oil pressure (60 PSI @ idle!!) and temp gauges, so those were a no brainer. My question is this: I added a voltmeter in lieu of the stock idiot light, but the only time it reads correctly (i.e. 12 volts) is with the key on/engine off. Start the engine and rev it, and the needle starts to move in the opposite direction. Reversing the polarity on the connections only makes it worse. Is this because I have a 12 volt positive ground, generator-based system, and my automotive-style gauge doesn't recognize it? I don't have a problem running a new wire to make it work right; just need to know where it goes on the gen. Thx for any and all help....
This should be a negative ground system so maybe the generator needs to be polarized properly. Mine absolutely negative ground but has been converted to alternator. Check your connections at the ignition switch, etc. I also had to make up a new dash including an voltmeter. Used a new style switch that required some rewiring to do it.
There is no doubt that a 4500 should be a negative ground system, I have owned a couple over the years, still have one for a shop-tractor, and have worked on hundreds of them in the last 30 yrs, including a stint as a service manager at a Ford tractor dealership. If you have any trouble at all with your charging system once you repolarize it, do yourself a big favor by scrapping your generator and going to NAPA for 1-wire Delco 10 si alternator. They are about $45 and only require a hot wire to battery + or the starter battery terminal.
If you are considering changing to an alternator here is a link to detailed information for it. http://www.myfordtractors.com/delco.shtml There is also detailed information on the internet to do a one wire installation. Which is the way I have done it. If you do the change over and find the alternator will not charge unless the engine is running way past idle, the exciter in the alternator can be removed and replaced with another that will enable it to charge when the engine is idling. It is called a self-exciting regulator. It is for the 10SI alternator that was used on millions of GM vehicles. That alternator can be purchased at any auto parts stores for about $45.00. I purchased a couple of those exciters on Ebay and they quite inexpensive. Here is a link to one of the vendors that offers them for sale. http://www.ebay.com/sch/i.html?_trk...S5&_nkw=alternator+exciter&_sacat=0&_from=R40 I think I may have purchased one of the regulators at a local NAPA store.
Hey folks, thx for all the great info. I had assumed my tractor was a 12 volt positive ground due to all the funky readings I was getting on my multimeter, and the way the new voltmeter was reading. I cleaned up under the hood, and found positive battery cable is going directly to the starter motor (and then jumpered to the engine block), and negative to the starter solenoid. Hook up a voltmeter and it gives negative 12 volts. Here's a pic below. I don't have a service manual/wiring diagram yet, so I'm assuming this is incorrect?
Are those cables hooked to the battery as their colors "might suggest"? cause that can't be assumed on anything this old. DON'T change them. If you get NEGATIVE 12 volts with the red/postive lead to the red cable and black/negative lead to the black cable IN THIS PIC then that's correct for a negative ground system, and your cables should be repainted. The voltmeter should be hooked to any accessory circuit and ground (so it doesn't drain the battery while off), it doesn't have to deal with the generator/alternator.
Is your battery hooked up backwards?
Ya, red goes to positive terminal and black to negative battery terminal. I hooked the voltmeter right inline where the idiot light used to be on the original dash cluster......
That's the confusion here. Like the above pic shows, red/positive cable directly to starter motor, then jumpered to engine block. Black cable/terminal directly to solenoid....
That probably explains the weird voltage gauge action. On an alternator, and obviously on a generator too, the idiot light is off when the voltage is correct, no voltage difference at the idiot light. You want a voltmeter hooked between any switched hot and ground. I can't explain your wiring setup. A starter will turn backwards if the polarity is reversed. It would have to be modified internally to turn the right direction hooked up that way. I believe it's possible to discharge a battery and recharge it the opposite polarity.
That makes perfect sense on the voltmeter Delmer; I'll switch it off the "idiot light" circuit tomorrow. Wish I had a service manual; sure a lot easier than guessing.....
If your red cable is hooked to the "-" battery terminal, and the blue cable is hooked to the "+" terminal, everything is right, except the wire color. That is very common on older tractors. If you clean the top of the battery you should see a "+" and "-" near the terminals, and the "+" terminal is bigger than the "-" terminal on top post batteries. The best thing to do is use a digital multimeter set to DC voltage. Put the meter's black lead on your red wire and the meter's red lead on your blue wire. If you get a voltage reading without a "-" in front of it, everything is fine. If you get a negative reading, come back and let us know. I am sure that the wire colors are just backwards, because if your polarity was backwards,your starter would spin, but wouldn't throw the drive gear out to turn the engine. Delmer is exactly right on the voltmeter issue.
If it is a direct-drive starter, chances are that it is series-wound, so it will go the same direction no matter the polarity. I did not believe it until I tried it myself years ago, but I have successfully converted a few positive-ground systems to negative-ground systems and never touched the starter. If it is a PMGR (permanent magnet gear reduction) starter motor, then the rotation will reverse with the polarity. As long as the + terminal ends up on the solenoid and the - to the chassis/frame of the starter, then you're good.
I stand corrected, I thought I had tried that once but it must have been a motorcycle starter, permanent magnet like you say (where you feel the magnetic resistance when you turn the shaft, can't spin it like you can a typical starter) If the generator works that way, leave it alone, until you decide to go to an alternator, then "convert" it back to negative ground.
Are we sure this is positive ground? And not just backwards wire colors? I've seen a lot of old equipment with the wrong wire colors, but never seen an early '70s Ford tractor positive ground. If it is, somebody converted it.
Nope; red cable from starter motor goes right to positive battery terminal and is jumpered to the engine block. Does anyone have a wiring diagram from the service manual?
Quite a few more cosmetic improvements in the last few days, including a new grill and dash. Still trying to find the sheet metal piece they call a "roof" that goes at the front of the hood and keeps the hydraulic filler/filter shielded from the weather; seems to be NLA. Awaiting a ROPS-mounted LED light bar to throw some light on the situation....
Does the prefix of your tractor start with A/B or C. there are two types of diagrams for the ford 4500.here are both diagrams
Hey thx a lot Randy!! My 4500 starts with "C". I'm actually just about to start converting it today to a 12v negative ground system using a self-exciting, 1 wire Delco alternator. Good thing too; I cooked the old generator on Friday.....
Fabricated the "roof" cover this week (still have no idea why Ford called it that) over the hydraulic filter/filler to keep out the H20 (pic is before final trimming). I must have contacted every tractor salvage yard in the US I could find (w no luck). Have a lot of the aluminum diamond plate laying around, so I decided to bang it out and call it a day. I also added the light bar on the ROPS and two floods on the rear brackets. REALLY bright, will look fwd to getting them wired in once the 12v alternator rewire is completed in the next couple of days. Oh; original Ford decals are NLA, so a cheap Summit Racing set had to suffice...
OK, 12 volt alternator installed with completely new wiring (I gutted all the old stuff). Running great, but I have a couple of questions: 1)I have the "ag bucket" which doesn't tilt back far enough to really move a lot of material. Anyone know of a quick cure? 2)I have a hand pump-operated gannon on the back (in lieu of a backhoe) which I would like to plumb into the hydraulic line that's already there for the hoe. I would obviously replace the handpump with a two-way valve I have laying around here. Anyone ever do this that can advise of any trouble spots? Thx a lot!!
1. That looks like the standard bucket to me. I never really thought of them as not tilting back. Most modern loaders have auto non-rollback linkage that rolls the bucket forward as the arms go up. I guarantee it'll rollback far enough to put a load in your lap if you don't roll it forward as you raise it. You might have to carry your bucket about level with your hood, you don't have a danger of nosing over like you do with a skidsteer. 2. I've seen 4500s with two different setups. Some have power-beyond loader valves and some don't. In other words, some have a divertor valve beside the loader valve. If it does, you'll have to pull the knob to use your rear hydraulics. Otherwise, it should be pretty straight forward, you probably have a pressure line connected to your return line at the rear of the tractor. Just hook them to your valve and see what happens. Many 4500s were delivered with just a solidly mounted counterweight, no 3 ph, or backhoe. Please take a few pics of your 3 ph so I can steal any good ideas in it.
Hey Mitch, thx for replies!! Here's a couple of pictures of back end/line. So I guess I just have a T there at the end of that backhoe supply line, and route one side to the "in" on the valve/cylinder, and the other side to the "out" on the valve? No diverter valve on tractor (although my Case track machine has one).
Ok Mitch et al; I pulled off the gannon a few days ago to start upgrading it to full hydraulics (in lieu of the hand cylinder). Anyone have any idea how to correctly plumb into the hydraulic factory backhoe line posted above? I guess I need to find out if my bucket system is "power beyond". Anyone know how-to? Thx much....
Put a gauge on the line at the back, see if you have at least 1500 psi. If you have no pressure unless you pull a handle, just use a power beyond valve for your 3 point hitch and put it in line ahead of the loader valve. I suspect you are going to have to beef up your linkage a bit.
Thx Mitch. So if there is steady 1500 PSI back at that line, all I need to do is have a good circuit with a pressure return into the tank? I'm wondering why there is only one line there; shouldn't there be two (pressure feed/return) for the factory backhoe?
The return has probably been removed, or it may have not been installed. A lot of 4500s came with no hydraulics to the rear, just a weight box that sat on the backhoe mounts. One thing about messing with 40 y/o tractors, you can expect them not to look like they did. I'm trying to remember what the factory hydraulic hook up looks like. If I remember I'll stick my head under one.
Yeah, its DEFINITELY been modified since it came w a backhoe that would have required a return line. I fabricated some beefier top links for the gannon (pics coming), and I have the below cylinders to choose from (valve I'm going to use is pictured too). The picture in post #23 shows where I think it would be easy to put a "T" for the return (assuming I have 1500 PSI at the other rearward-facing line in the pic)......
A $45 seat from a junkyard Mercedes 300e has me riding in style & comfort I never thought I could achieve on this old girl. New gannon hydraulics coming over the weekend....