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HELP ! - My Tractor Engine Won't Even Crank !

This is a new page, basically just a brain dump. It needs a re-write, some photos, and proof reading. Please pardon typos, and stuff out of sequence, until I get a chance to do it right. This guide can be used for more than just old Ford Tractors. Most of this stuff is true for any vintage internal combustion engine.

If the battery is just run down too far to crank the tractor, they usually have enough change to run the ignition if you can pull start the tractor with another vehicle. A convenient hill might even be used to bump start the engine. Only problem with that is if it does not start, now it's at the bottom of the hill. Jump starting using jumper cables from another vehicle is easy enough if both vehicles are the same voltage. Always connect batteries plus to plus and minus to minus. Do not connect 12 volt and 6 volt batteries this way. It is possible to jump a 6-volt tractor from a 12 volt battery. Instructions for jump starting are HERE

WEATHER REPORT

How's the weather? Did you just power-wash or sand-blast your tractor? Has the tractor been in a flood?

If you are trying to start a tractor that hasn't run in years, is years behind on maintenance, or has just been involved in a fire, flood, sand-blasting or other foul weather, Please GO HERE FIRST>

BATTERY AND CABLES

Before replacing the battery or starter, check your battery cables. Your cables may be too small, damaged, and your connections may be less than perfect. Remember, 6 volt systems draw more amperage. All wiring and connections should be as close to perfect as you can get. Is the battery dead? Check it with a voltmeter.

Some people might think 10 volts on a 12 volt battery is pretty good. It's more than half, right? Wrong. For a 12 volt system, 100% charged is 12.6 volts, 50% is 12.0 volts and dead flat is 10.5 volts! Divide those by 2 for a 6 volt battery. At anything less than 50% charge your battery is considered dead-flat, and may be too far gone to even accept a charge! Put the battery on an external charger. See if it will accept a charge.

If the battery cables are skinny little automotive cables, they are junk. If battery cables have the bolt-on terminal ends, they are junk. If the battery cables have any deformity in the insulation, they are junk. If there is any exposed copper that has broken down into that blue/green stuff, they are junk.

Tractors should have a braided copper ground strap rather than an insulated cable for the grounded terminal. The cable to the start solenoid should be at least 1/2" diameter insulated cable. If the insulation is marked, the size should be #1 is OK, #0 is Better, #00 or 000 is Excellent! Clean both ends of both battery cables. Take the battery terminal clamps loose. Use a wire brush type battery terminal cleaner on the clamps and battery posts.

Battery Terminal Tool

Use a scraper or file to shine areas where cables connect to the solenoid and to chassis ground. Make both sides of every connection clean and shiny.

STARTER CHECK

Test the Starter. Ignore the tractor voltage, cables, wiring, and solenoid. Ignition switch is Off. Put the tractor in neutral. Make sure you can move the engine a little by hand. Grab the fan belt, and pull. The engine should turn a bit without too much trouble. If that checks ok, we need a good battery, and jumper cables to test the starter. Connect the jumper cables to a good 6 or 12 volt battery. Clamp the other end of one jumper cable to any good ground on the tractor. Check again, make sure the transmission is in neutral. Then touch the other jumper cable clamp to the terminal stud on the starter motor. Polarity does not matter. The starter should immediatley crank the engine. If not, check the grounded cable connection point and try again. As a last resort, try touching one cable to the starter case and the other to the terminal. If the starter won't crank the engine, it is bad. A rebuild kit for the starter is about $25 and usually includes a set of brushes and a new bearing. The manuals thoroughly cover procedure for checking and rebuilding the starter. A rebuilt original starter will probably be better quality and last longer than any of the new replacement starters available.

SOLENOID CHECK

With a good battery and cables installed in the tractor, make absolutely sure your transmission is in neutral. Then try simply grounding the small start terminal on the start solenoid. The engine block is right there, so unless the engine was recently painted, finding a place to ground the start terminal should not be difficult. If necessary use a short piece of jumper wire to connect the small terminal to any good ground. If the engine cranks this way, but won't crank when the start button is pressed, the problem is in the wire to your start pushbutton or the button itself.

THE START SOLENOID

There are at least 3 different types of Ford start solenoids that look very similar. A 3-post solenoid is correct for most tractors. This solenoid only has one small start terminal. The electronagnetic coil that operates the solenoid is powered from the main battery terminal inside the solenoid. The one small terminal connects to the start pusnbutton, and becomes grounded when the button is pressed. This solenoid only works correctly when it is mounted to the starter with the small terminal facing the engine block. Turn it around and it won't work. Because the start terminal is "hot" all the time, the engine will crank any time the start button is pressed. The ignition switch ON or OFF has nothing to do with the engine cranking.

When some people go buy a 12-volt replacement solenoid, what some parts stores sell them is the automotive type 3 or 4-post solenoid. These other types may look similar but will not work on a tractor.

Hopefully one of these tests has identified the problem, and the tractor is now starting and doing fine. Sadly, that might not be the case. If it cranks, but still won't start, try the stuff on the next page - Won't Start

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Content and Web Design by K. LaRue — This Site Was Last Updated 10 APR 2019.
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