wont start or shut off....

['72f250]

i have a '72 f250 with a '73 351 cleveland. i bought the truck that way so im not sure what exactly was done when it was swapped. that being said...

ok...the original problem was that if you jump started it, it would start and run fine until you shut if off. then it wouldnt start back up. the selenoid just clicked. i tried charging the battery and finally buying a new one. it still did the same thing. So it seemed like an alternator went bad. no biggie, i had one laying around that i knew worked fine so i put it on. that didnt fix the problem. so there was also a wire that was never hooked up ever since i got the truck. i thought for sure that had to be it, i hadnt hooked it up at first because the truck was fine for a couple months with it unhooked.
before i hooked the wire up, the truck would shut off if you disconnected the battery while it was running. after i hooked the wire up, it ran fine with the battery unhooked. i figured that was the problem so i drove it around a little bit to let the battery charge up. when i got home i went to shut it off and it didnt shut off. im listening to it run with the keys out of the ignition. but when you shut the key off, the radio goes off. anyway i popped the coil wire to shut it off and now its still wont start. the selenoid just clicks.

[flyboy2610]

Replace the solenoid.

['72f250]

are you sure? i have the one off my old truck thats brand new, ill try it but im not sure that it sounds like the selenoid is the problem, i could be wrong

[lrjetmech]

Would definitely change the solenoid, and look up the wiring diagrams to make sure the wiring to the solenoid is right as well!

[TRMMULLET]

Is it a 4 pole relay?

['72f250]

alright well i replaced the selenoid and let the battery charge all night, it seemed to fix the problem so i drove it around and shut it off and started it a bunch of times. but then one time it just didnt start back up. i cant think of anything that would be draining the battery and ive tried two alternators, one of which works fine. i know that for a fact. its a new battery and a new selenoid. im stumped.

[ToughOldFord]

Regulator?

[lrjetmech]

i drove it around and shut it off and started it a bunch of times. but then one time it just didnt start back up.

Depending on how many times you shut it off and started it again, it could have drained the battery down low enough to not wanna turn over. Even on a full charge on a new battery, several starts in a short amount of time is death to a battery, if the engine doesn't run long enough to charge it back up some! Just a thought!

[lrjetmech]

Did you look here to check wiring? http://www.fordification.com/images/sch ... _quick.jpg Just a thought!

Also, is the battery's cranking amps enough to handle alot of cranking over? Have had that problem before when using a battery out of something that wasn't "hoss" enough to handle an engine not wanting to start, or having problems starting, especially a V-8! JMO!

['72f250]

yes i know that you can kill a battery pretty quickly by rapid start and shut off, start and shut off..etc. im not stupid by "a buncha times" i meant maybe 4 or 5. also, i changed the voltage regulator on the core support and charged the battery for about 4 hours and it started and ran great until i shut it off. it cranked slow a couple times and that was it. do you think it could be the starter? it has a new battery, selenoid, alternator, and voltage regulator. i hate electronic problems

[lrjetmech]

yes i know that you can kill a battery pretty quickly by rapid start and shut off, start and shut off..etc. im not stupid

No disrespect meant, just checking!!!!!!!!!

[ToughOldFord]

Since it starts after charging the battery it's probably no the starter. If the starter was heating up and dragging then all it would take to restart would be to cool off, not a recharge on the battery.
Hook up a volt gauge at the battery, check your voltage at the battery when the tuck is off and when it's running. (Idle and higher RPM) Then you'll know 100% if you're charging or not.
You can get those digital volt gauges that plug into the cigar lighter, Wal Mart has them for $14. I just leave mine in all the time since the Ford ampere gauges really aren't worth a darn. Good way to keep an eye on your battery and charging system.

[bobbyinpd]

alright well i replaced the selenoid and let the battery charge all night, it seemed to fix the problem so i drove it around and shut it off and started it a bunch of times. but then one time it just didnt start back up. i cant think of anything that would be draining the battery and ive tried two alternators, one of which works fine. i know that for a fact. its a new battery and a new selenoid. im stumped.

Wire in a GM one wire alternator, they cost less, work better, and make it so you can throw out the ancient, unreliable voltage regulator and all that unnecessary wire. Just buy the alternator and the connector and run your 2 wires and then you are done. Goodbye Poor Charging!

['72f250]

well thanks for your input guys, i ended up putting a brand new alternator on it and then a few minutes later, we found a wire that had corroded and broke. the whole time, it was one damn wire. oh well, good learning experience.

[willowbilly3]

Regulator?

Most likely.

BUT, you need to troubleshoot the system and quite guessing and throwing parts at it. I am sure there are some tech articles right here in the tech pages if you take a look. It's not a chevy, Ford alternators just don't fail that often, but regulators do. You can jump across the regulator plug from the first to the third slots and full field it to see if the alternator kicks in. You should turn off all accessories and not rev the engine during this test.
You might want to get that unhooking the battery stuff out of your head, yeah it works but it is way too easy to damage something and if you keep it up you are going to really screw up someones computer controlled vehicle, or even let the smoke out of your stereo, all your lights ect. All it takes is for someone to hit the throttle a little and you could send 18-20 volts through the whole system. That was something they did back when cars had generators, over 40 years ago.