So I bought a 1979 F250 from a guy who had only used it for hauling wood in the winter before. It was rusty but he said it ran well and when I drove it it ran fine. Since he hadn't used it in a while he charged the battery for 24 hours before I test drove it and it started with no problem. After that it got harder and harder to start it. When I turn the key it cranks but doesn't turn over. I know nothing about cars so I need a little help knowing what is keeping it from starting properly. There are no weird noises I can notice when I try to start it or once it is going. I got the battery tested and the guy said the battery is within the last quarter of its life so I want to change it anyway but I want to know if it might be something else. Any ideas?

 

A battery that only holds a 1/4 charge is toast. Get a new one installed and try it.

 

Welcome to the forum, Magic#97!


With so little information to go on, it is just a guess, but it does make sense that the battery is the first place to start. The fact that the previous owner felt the need to charge the battery just before the test drive leads me to believe that he knew the battery was/is weak. If, indeed, it is the battery, the engine should be able to be "jumped or boosted" with the aid of a second battery.


When replacing the battery, check all cable connections to make certain they are clean and tight.


Be very careful not to short out anything when installing the new battery!

 

Check for battery fuzz

edit: sorry, not helping here :P

 

So I changed the battery and it kinda helped but after 20 hours I still needed a jump to get it to start, but before a jump didn't even get it to start so it's better, but not fixed. What should I check next?

 

Alternator output.

 

I had someone at an auto parts store check that and the battery, he said both were good, the battery I realized later was worthless but I believe the alternator is fine. I can start it 20 times a night if I drive for 10 minutes and leave it for thirty. Is there anything else that could be wrong?

 

It sounds like you have something in the truck which is draining the battery. This can be an accessory or a short.


Loosen the negative cable from the battery and connect a 12V test light between the battery terminal and the loosened cable. Make sure the cab doors are closed, so the overhead light will not be on. If the test light lights up brightly, something is pulling current from the battery.


Often times, this is either a messed up trailer hitch connection or aftermarket stereo/amplifier.


With the test light illuminated, pull one fuse at a time until the light goes off. That will determine which circuit is the drain. Then, you have to determine why.

 

When I changed the battery the problem changed as well, now the truck is turning over when I turn the key but the engine still isn't starting. I'm absolutely clueless about what's going on, what could cause this?

 

If you spray some carb cleaner or starting fluid into the air cleaner/carb as you crank, does it fire up?

If it does, the problem is fuel. It should fire up, then die. You probably arent getting fuel, whether it be a fuel pump, clogged filter, etc.

If this doesnt work, then there are two other options. One of them is air. Are you getting any? Make sure the filter is good and clean.

You also need spark. Take the spark plug out and lay it on a piece of the frame or engine (away from combustible materials of course). See if it sparks as you crank the engine.

It will almost definitely be fuel, fire, or air if the starter is engaging and spinning properly.

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