Farmall H - Hard to start & wires heating up

I have a 1949 Farmall H that is having trouble starting. It responds very sluggishly and only turns over a rotation of two at a time. It will eventually start after I have pushed and held the switch maybe twenty times. The switch (and cables to it) become almost too hot to touch before it will start and they will actually smoke if I try too many times. Once it starts, the switch and wires cools down. Although I am planning to switch it over soon to 12 volt, it is still a 6 volt system with the positive ground. The battery is brand new also. I am looking for any suggestions or was wondering if anyone else has had this problem before. Perhaps a bad ground? Or am I losing voltage across a bad starter? Any thoughts would be appreciated! Thanks.

A six volt system has to have everything right to work right. That means heavy battery cables, I've seen 00 gauge recommended, clean terminals, good clean tight connections everywhere. What you are describing is either too small gauge cables, loose or dirty connections. No doubt going to 12 v is a better deal but a six volt system will work OK when everything is right.

As Charlie said, the cables have to be the proper size. Given that, is the heat uniform along the cables/switch or is there a hot spot? If one or two spots, they are at bad connections or deteriorated cables. Fix the spots. If the heat is uniform, you probably have a bad starter. If you have a bad starter and change from 6-volts to 12-volts, it will seem to be better for a little while, long enough for you to post back how well it works since you converted it. Then the starter will go up in smoke.

Check the simple things before throwing money at it. I removed the ground wire from frame and buffed cable ends and the tractor to remove some rust, which helped. I replaced cables and ends with heavy duty. But that was AFTER i burned up a starter by cranking on a low charge battery. Make sure ur battery is charged, or get ready to rebuild a starter. It's amazing how a 1/2 turn of a wrench will help things.
If it's smoking, bad things are happening.

That can be caused by a number of things and I will try to list a few of them

#1 poor connections
#2 starter going bad and pulling to many amps
#3 battery cables are going bad and you cannot see that with your eyes. Cables can/will go bad over time.
#4 battery cables are to small for a 6 volt system. 6 volts use higher amps due to lower voltage so the cables need to be a lot heavier then on a 12 volt system.
#5 starter button is going bad and not conducting power like it should be.

And there is probably a few other things that can cause that problem

Poor connections, bad cables or cables that
are too small are all factors here. No need
for 12v, if you have new OO cables and
clean connections it will start just fine.

The very FIRST thing to do is REMOVE (NOT just inspect), clean and wire brush each and every battery post,,,,,,,,,,battery and ground cable and ends,,,,,,,,,,,,frame ground connection,,,,,,,,,,,starter,,,,,,,,,, and starter switch connections.

Smoke and heat is due to a resistive connection in the circuit or else way too much current draw.

For good 6 volt operation you need good heavy cables such as at least 1, better yet 0 or even better 00 Gauge battery and ground cables, plus as noted above clean shiny bright battery and ground and starter and switch or solenoid connections.

Typical causes may be bad cables or connections,,,,,,,,,,bad resistive starter switch,,,,,,,,weak battery,,,,,,,,,bad starter

It may help to relocate the ground cable to a clean shiny bolt located on or near the starter.

If when you crank her the lights dim way down bad and voltage drops drastically,,,,,,,,,starter motor may be bad or shorted or stuck.

If when you try to crank her lights don't dim much and voltage dont drop much but she cranks slowwwwwwwww the starter switch may be bad or there's a bad cable or battery or ground connection

You might try to by pass a faulty switch by using jumper cable from battery to starter n see what happens???

John T

Why not get the starter refreshed

I agree, make sure all connections are clean and tight.

Try cranking it with coil wire pulled, that will tell if timing is an issue.

I would measure voltage across battery, then across other components, make a list and report back.

It is one of three things, excessive current, high resistance, or bad battery.

I correct, at least one of these things is wrong.

(quoted from post at 09:42:57 04/11/17) Why not get the starter refreshed

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Because cleaning the connections is cheap, quick, easy, and you should always try the cheap, quick, easy solutions first.

Also, there just aren't that many starter shops around that will do a proper job of refreshing the starter anymore. Most of the ones that do exist will simply try to sell you an overpriced aftermarket starter that you can get for half as much off Ebay.

o k, how does cranking, with coil wire pulled, help with diagnosis?

Thanks for the tips! I’ll take all the connections apart tonight when I get home from work and clean off EVERYTHING. I’ll let you know how I make out.

Ground the battery right over to the starter mount bolt. Makes all the difference. Eliminates all the rusty old corroded frame joints trying to conduct electricity.

That has been my experience. Having a starter rebuilt is a waste of time unless you are sure of your shop's abilities.

Timing too advanced will make the starter hard to push over TDC,

thanks

Ok, I'm back from finally getting around to my issue - had a family situation to deal with. I checked out the all wiring. What I found was a fair amount of corrosion on the push button switch. I also found that the start switch had a broken post and was arcing. Not surprisingly that is where the hottest section was and the most smoking. Going for a new one tomorrow. All the connections are cleaned up now and glistening. Hope the starter wasn't damaged during all that. I'll see how it works tomorrow!

Just a follow-up to the smoking electrical problem and hard to start issue with my Farmall H -

I cleaned off ALL the terminal/connector ends and replaced the starter switch. It starts fine now. The terminals at the switch were pretty bad. That said, the switch was also fried. The post from the battery was broken off inside the switch and was arcing across, hence the heat. Also, the smoking was from the rubber insulator flap on the back of the switch (between the two posts) burning/melting. The only replacement switches I can find for this are all the same – cheaply made from China. Hope this one holds up better….