My New Old H

Hey guys wondering if I could get some help on my Farmall H? I have a lot of questions about the electrical system. I thought the main problem was the battery, but after a new battery with a full charge it barely, if at all, turns the engine over and the Battery cables are actually getting hot enough to melt the wire casing. It has the 6v positive ground with a new 6v battery, new generator, new regulator. The ammeter is new but is not the 20-0-20 or D-O-D type. The wiring harness has been patched in several places. It has the original H switch with the original guts in it. I added a battery cut off switch when I thought the battery was draining.
when cranking the starter the volts drop down to at least half. Must have a short somewhere. I was hoping someone would be able to get me started and talk me through trouble shooting this tractor. Thanks

Make sure your battery cables are in good condition and of
adequate size. Run your ground cable directly from the battery
to one of the starter mounting bolts. If that doesn't help your
starter is probably dragging. Hope this helps.

If it has light weight cables that is probably your problem. Had starter shop make me some 00 cables and my Super H works ok now.

First i would get the starter refreshed then get new 1ga cables ground to the starter that will make the starter work like new again. Now the charging system. With an ohm meter check the gen one lead to the ground other to the gen body to make sure it has good ground same with regulator and lite sw if you polorize the gen it should charge providing the wiring is OK. You can put the probe on the knob of the lite sw to check it as all componets in the charging circut need to have ground to the battery as paint ect on other parts of the tractor are hard to find bare metal so i just check to make sure they have ground to the Pos terminal of the battery.

I agree with the other posters as well about the possibility of the battery cables. Generally, the battery voltage will drop somewhat when any vehicle or tractor is being cranked. That is also a reason why good heavy cables are so important. If you have small or poor battery cables on a tractor you can easily be losing volts across the cables any time a large amount of current is flowing through them, such as 75 Amps of starting current (typical starting current for some motors). For example on a 6 volt system with bad cables you might be dropping 2 volts across the cables, leaving 4 volts or less at the starter. This is where a system converted to 12 volts can "hide" the bad cable problem somewhat because in that case, 12 volts with 2 volts cable loss still gets you 10 volts at the starter to start your tractor......and if you are running the 6 volt starter with a 12 volt battery it will be more than happy with the 10 volts.

When I first got a few old tractors, several of them had smaller gauge cables that would have likely been the smallest and cheapest ones at the local supply store or else used ones from a car/truck. I now get heavy cables made up at an electrical shop with the proper ends crimped on. It's like night & day difference.

Red
Electrical Engineering Technologist, in the business for 26+ years.

You need cables about the size of your wrist.

It sounds like we have a consensus. New Battery Cables. Found some wiring diagrams showing 1 GA. I will give that a try.

I also pulled the starter to see how it acted with 6 volts/15A hooked up to it direct. It started slowly but then spun up in RPM fairly quickly. With 12/2A volts it spun really quick with almost no delay.

I removed the battery cut out that I installed last summer and it helped slightly. At least it will crank now once the crankshaft is in the right spot.

I peeled back the electrical tape on the patched wiring harness and found soldered splices that are just taped. They are splices between the original wire with cloth sheathing and newer type wire with plastic sheathing. I will grab some new wire and connections. It looks like 14 ga & 10 ga is what I need. Checked connections found a bad one on the coil. I put a new end on and re-installed.
Opened the hood on the regulator. One set of points is closed and one is open. No change when cranking the starter is this normal? One set has a wide gap and one is almost closed.

I cleaned the edge of the switch box and the groove in the cover plate for better grounding. I have a little more than 6 volts both sides of the ammeter. does anyone know how to test the switch itself with a voltmeter? Probably need the tractor running for that? There are no lights on the tractor so not much to test there. I was considering running a ground wire because this connection will just rust again.

I am off to the hardware store for new battery cables. I will hook the positive up to the 3/4" starter mount bolt. Thanks for your help. More later.

Thanks Gene, OK this will be easier if we take it in bite size pieces. by starter refreshed you mean new brushes and bushings?
I found Napa has 1 gauge cables. I will put them on tomorrow. The positive is a 4 gauge now and the negative has been painted but may be a 2 gauge.

Sounds like those cables may be a lot of your problem. Try the new ones first. Make sure all the connections are cleaned up really well. If that doesn't do it, then, as mentioned, have someone go through the starter.

Surely not! I think you meant thumb

OK, your wright.

I have several original 6 volt Farmalls which I have maintained as 6 volt tractors and I use 00 cable with soldered terminals on all of them and I don't have any of the issues frequently discussed here similar to yours. Any good auto electric, NAPA, etc. can custom make them for you to your dimensions with the required terminals. I also attach the ground cable to one of the starter to frame mounting bolts whenever possible. Get everything clean and bright and use an external tooth washer to get a good metal to metal bite into joining metallic surfaces along with a small amount of di-electric grease. Hope this helps, Hal.

Re-emphasize what Old Weldor said - run the battery strap directly over TO the starter mount bolt. Very important, this will eliminate lots of voltage loss through rusty frame joints.

I agree with farmall hal...could not get a wd45 to fire after sitting for 15 years. Because I needed something to do while i thought of my next mode of action, I sprayed EVERY ELECTRICAL CONNECTION with some contact lube. quite certain i would get no response I hit the starter and it fired up and ran as if it ran just hours earlier!

Thanks Guys for all your help on the Battery Cables.
I now have new 1 Ga cables. Positive goes to the starter frame mount bolt. (well cleaned) The negative goes to a remote mounted spring loaded typical Farmall starter switch. Mounted on the Diamond shaped bar below the throttle control. The other leg has a 1 Ga cable going to the starter. All Cleaned good connections. I will check continuity everywhere before I attempt to start but I am pretty sure there are no issues with the new battery cables.

Now I need help with the wiring schematic and making sense of the wiring that is currently in place..... I have a mix of the old farmall 4 position light switch and new regulator with new generator. SO I am wondering if there is an issue here that is causing a direct short. I will try and describe it starting with the charging circuit.
So, negative on the battery goes to top post on starter switch which is shared by a wire that goes to 1 side of the ammeter. The other post on the ammeter goes to the BAT terminal on the regulator.Gen on the regulator goes to A on the Generator. I think this is right from what I can see from the diagram.

Now for the rest of it...... From the regulator, L terminal goes to the screw next to the top of the fuse which is on the back of the old 4 position light switch. That same screw is shared by a wire that runs to the ignition switch(or push/pull button kill switch, whichever you want to call it) The other post on the Ignition switch goes to the negative side of the coil. Than the Positive on the coil goes to the distributor.
I have no lights on the tractor and the ammeter needle moves when I move the 4 position switch. It is the wrong ammeter it is a-60 0 +60. I will change this out later. I rewired the whole thing with new wiring and got rid of all the splices and patches. any body see anything wrong? I am thinking of bypassing the old 4 position switch all together since I have no lights and the Regulator should do the job of the old charging positions on the light switch. What do you think?

Thanks guys for all your help. Its rewired, I have
new cables and its running great. Starts right up!
I still have some minor things to do, but its time
to start getting firewood in.
Thanks again for the help.