Help with 95 ford f150

the battery went dead over night. when i jump it, it starts but shuts off when i step on the brake. it did this before but was a loose battery terminal. i replaced them and now it does it again. also my cylinoid, starter and alternator keeps going out.

You may have killed the battery by letting it deep discharge. If it’s over three years old it’s probably due for replacement. Also check the charging system. Asking an alternator to recharge a dead battery can cause damage to the alternator.

Tester

had battery tested 3 times they say it is good, could the voltage regulator or ignition sticking cause this problem

If there are bad diodes in the alternator, that can pull a battery down as it sits.

Tester

still doesnt explain why it shuts off when i hit the brake or why cylinoid starter and alternator keep going baed. i understand what you have said.

If the battery is dead and alternator isn’t working, the engine will shut down because there’s no power for the injectors, it won’t run.

A dead battery will also kill a starter by not having enough amperage to turn it.

Skipper

It turns off because the brake lights draw what little power is left in the battery.

Tester