Ford 5000 Generator Light On

Personally, I got sick and tired of fighting with that charging system. For that matter, I don't fight or even waste much time diagnosing the charging system on Ford tractors. The simple fact is that it costs more to replace just about any single component in those systems than it does to throw a rebuilt Delco alternator on them. It will cost more on the thousand series to go to an alternator because you need a tach drive on the alternator.... but once it's done, it's done. You can check around the parts department on this site or look at Tisco for a Delco conversion for a thousand series tractor. There should be kits available that will have the alt with tach drive and the brackets. That will about solve your charging problems, and give you a good 50-70 amp alternator to run lots of lights. Anyhow, it's just another option. It may cost a bit more up front, but in the end I'll just about guarntee it'll cost less. Good luck.

Rod

Now.. start engine.. bring idle up. On my 5000, lamp won't go out till you hit around 800-900 rpm or so.. though i have seen it kick out at lower if it is in a good mood.

What has happened is that the genny is producing power.. once the genny is producing the same amount of voltage that the battery has, there is no longer any current flow thru the lamp, and it goes out... You have to have a difference in potentials to get current flow.

Sounds like you have a bad lucas vr.. or weak genny. My bet is the lucas vr.. their points are prone to coroding and sticking. Sometimes the cutout won't pull in.. so even though the genny is producing.. nothing is charging.

The fact that the lamp comes on with the key switch leads me to believe the key switch is good.

You have got at least 3 options. The 'right' way, an 'acceptable' way, and a 'cheap-but-usually-works' way.

Right way: get a new 25$ lucas vr.

Acceptable way: Get a 40$ vr made for a 12v diesel hundred series. These hundred and thousand series all used B-Circuit gennies. The main difference, is the 5000 genny is only about a 20a unit.. and it's vr would tend to help limit that. The 'will-fit' hundred series vr's.. you can find them with up to a 25a regulated output... thus.. in some instances, you can actually load the electrical system too much and the vr will ask for 25a.. vs the 20a. for short term.. this is no big deal. but I wouldn't ask for 25a out of a 20a genny for full duty. in fact.. i wouldn't ask for 20a from a 20a genny for full duty... gennies aren't as good as alternators for that sort of full time demand. I typically like to use no more than 2/3 to 3/4 load of my genny for full duty use.

Just add your load amps and figure your load. If you have watts instead.. use ohms law. 20a at 12v is 240w.. thus.. you have up to 240w safely available at max load for that genny... I'd keep it at 160w to 180w to keep the 66-75% load number going for long term genny health. A typical headlamp is 55w. Thus you can run 2 headlamps and a rear work lamp for 165w, and add in a 15w fender mounted blinker and you are at 180w and right on target.. and that even allows 5a for battery charging, if needed, and still just be in at 100% load.. and not over.

Now.. the last way.. the 'cheap-but-usually-works' way.

Some times these lucas VR are not bad.. but just marginal. The weak cutout doesn't like pulling in at low power. If you full field the genny, and make it produce at max for a second, that usually kicks the cutout in on a marginal vr.

Since this is a B-circuit genny, you full field it just like you polarize it. that is, you jumper Battery to field for a second.

On my 5000, I sometimes had to do this. I had a spare hole in the dash, curtesy of the prev owner, so i installed a momentary push button switch.. nice metal one.. marine grade. I wired one side to power.. picked it up of fthe ignition switch. The other end i ran thru a fuse, and then zip tied the wire to the tach cable and ran it right down the tach cable to the genny. From there, the field connector is a blade tap at the top rear of the genny. I used one of those push on 'tap' splices and just T'ed my wire into the VR's field wire right at the genny.

Now.. when i get on, and if the cutout doesn't pull in right away, i just push the button for a second and she pulls right in.. even at 600 rpm idle. I also use this if it is cold out, and i don't want to idle the engine up to 900 rpm real fast to get the genny to charge. Just a 'taste' of the button makes it work. Don't hold the button for more than a couple seconds.. and do make sure it is a spring loaded momentary switch.. not a push on/off push off toggle. The reasson for this, is while the genny is full fielded, it will make max output. If you are at sufficient rpm.. I've sene these old genny kick up to 30a while full fielded... and we don't want to do that for more than a second or two... course.. at lower rpm.. it doesn't kick out that high.. probably not more than 8-10a at idle, even full fielded.. Now.. this fix only works if you have the sticky cutout. if your VR field circuit is just completely gone.. then choose one of the other 2 ideas above.. * ( In an emergency you can get by with no field circuit, as long as the cutout still works, by putting 2 old gasser ignition resistors in series and tieing one to the armature, and the other tot he field... it provides some field excitation and makes power..... ) In fact.. in a pinch.. you can run without a vr altogether. I had a 66 cub, 12v from the factory.. vr did not work.. and I didn't feel like fixing it as i just mowed with it.. and I had it on a solar charger. the month between mowing charged it up. One day I needed it and couldn't get a vr, so i rigged up a high current 25a rated DPDT center off switch. I used 2 resistors. A low value one2.5 ohms or so.. and a high value one 4.5 - 5 ohms. I wired the switch and resistor so that in one position, the low value resistor was between field and ground on this a-circuit genny, and it's armature was connected to bat on the other 'throw'side of the switch. i did the same on the opposite throw.. except with the high value. i now had a low/hi charge switch, that when centered, was off, and acted like a cutout. The low value ressitor made a high charge.. the high value ressitor made a low charge. old cubs and IH had a similar setup to this anyway with a charge switch and headlamp switch that tickled the genny / vr... Anyway.. that cobble ran fine till I got a working VR... anyway.. sorry for rambling.. that last storry didn't help you very much.. just pay attention tot he 3 possible ways up top that may get you back going.

Unless it is a show tractor.. i like the cheap and easy way.. if it will work. A jumper wire with gator clips will tell you if it works.. start tractor, and jumper bat to field.. if lamp goes out after you unjumper.. just throw a switch into the dash and add the wires. This can also be used as a 'repolarize' button if you ever swap vr or genny, or battery to change polarities or for repair work.. etc.

post back if you need mroe info, and to let us know how it worked / which option you chose.

Soundguy