My car will run without a battery connected once it has started.
An alternator needs power from the battery to magnetize coils before it can generate current. If you push start it the alternator may have enough residual magnetism to generate enough electricity to start the motor but I very much doubt it. It would have to generate enough to start several computers, turn the electric fuel pump, open some solenoids etc. Even if it did start, running it without a battery would definately stress the alternator and might ruin the computer. Spending 40-50 to buy a battery before starting it might save you several thousand in repairs later.
It doesn't. You still need a current running to the alternator to start the truck. They can be push-started by someone pushing the truck while someone else sits at the wheel with the truck in 1st or 2nd gear with the key in the on position. Once the truck picks up enough speed, release the clutch and give it some gas. However, as I mentioned, this method likely will NOT work without a battery (but can work with a weak battery or a starter problem).
I have a VW rabbit diesel and it is all mechanical. The only thing it uses electricity for is to keep the fuel solenoid open. It pull starts with no problem except that it stresses the timing belt. I had it break an oil ring one time and it sucked up engine oil through that piston in large enough amounts that it would not turn off because it was running on the oil. I stood there with the key in my hand and the little engine chugging away happily. I had to put it in gear and pop the clutch to kill it.
haha... I had an old 67 Dodge pickup that used to run like that too.... It truly had a mind of its own.
How old is it - Has it NEVER had a batteryIf it should have one you either need to replace it OR find a very steep hill or a lot of strong friends to push it.If your push or hill starting use 2nd gear.
You could try a hill start, (Put the truck in 1st gear, holding the clutch in. Get the truck rolling down an incline and then release the clutch.) but I think that the way cars are wired you need a battery in the circuit, even if it's dead. I don't think the alternator directly provides power, it has to pass through the battery.
The alternator will provide power, when turned. But the regultaor is designed to work with/against the big buffer of a battery. So it might start but maybe not run smoothly. You may also kill the catalytic converter with a hill/push start - try to connect your truck with a working battery and put a battery in your truck - even an old one.