Ive got a 1996 Ranger 5 speed. having some electrical problems the battery acts as if its dead when you try and start it you can do the hill method to start it and the battery gauge shows as if it was normaly charged but it will fluctuate a little bit then when you pull up to a red light and kick it out of neutral it will go all over the place and almost try to die. You can jump it off ive taken the battery terminals off and cleaned and tightened them up and you can start it leave it running for two minutes or an hour and kill it and try to start it again and its like the battery is comepletely dead. I put a two month old battery on it and to the same result comepletely dead, although it did sit in the battery crate of an old late 70s truck i got in temperatures in the teens so it could be dead already the only things i can think of are the battery or the alternator i might be missing something as this is the newest truck ive dealt with by far 60s 70s and 80s is more my speed. one more thing i i went to eat with some freinds of mine sat in the resteraunt for quite a while accidentally left my lights on treid to start it and it started right up.

 

Sounds like you need to start eliminating things. The easiest way for you to do this would be to have an electrical system test at an O'Reillys or the like, let them test your battery, which from the sound of things is of unknown/unreliable/unproven condition and the alternator.The principles of battery charging systems haven't changed in any significant ways since the vintage rides and today (ok, alts w/internal regulators, no biggie), and batteries, outside of AGM's, are still lead acid. You should also do the obvious inspection of connections between the battery, the alt and also the associated grounds.

 

welcome to FTE. if you have a voltmeter, just hook it up to the battery. at idle should be reading at least 13.8 volts. if not then the alternator is probably toast. as said above you could also get the system tested at an autozone or similar shop.

 

While you were checking various electrical connections, did you check the various connections between the battery and the starter. Corrosion on any of those contacts could create the kind of problem you are having. Going over all of those connections with a volt meter as another poster suggested would be a good idea, not just the connections at the battery.