massive power drain on battey

[1986bronco2]

i tried to pull the codes from the broncos ecu lastnight to find out why it would run for a bit and then shut off, but the battery was dead. so i tried to jump it to no avail. that said, i (against better judgement) pulled the battery from my truck since i knew for a fact its good. and hooked it to the bronco. after installing the truck battery into the bronco i then tried to start the bronco and it didnt even try to crank just simply heard click,click,click and so i thought what on earth is this crap(i had ran the truck not 10 mins prior to pulling its battery) so i rechecked my connections and found the neg cable to be loose. tightened that and then tried to start the bronco again and got the same click click click. so its extremely apparent that i have one heck of a massive power drain somewhere since the bronco completely killed the trucks battery in less than 10 mins or so. (this is a new thing as this didnt happen the last time i had it running) also the battery from my truck is a duralast gold with 1000 cca at 32 deg when i tried to jump start the bronco it literally killed my truck when i hit the key. it cranked about 3 or 4 times then started crankin slow so i stopped and decided to wait for a few to let the battery get more of a charge and when i tried again as soon as i hit the key my truck shut off. so im starting to think an auto electrician is going to start getting a nice chunk of money from me in the near future. like i said this is a new thing that its doing. i havent messed with it much in the past couple of months. im at a loss here and this is beyond my knowledge when it come to vehicles. so if anyone has any ideas as to what could be causing this any info at all would be great.

 

[RonD]

Reads like a short in the starter motor or solenoid.

Just replace the solenoid and remove the starter and have it tested, that is usually free at some parts stores.

It could also be an alternator with an internal short, draining battery, but more likely starter motor is drawing too many amps, but since battery was dead when you first tried to start it, I would check the alternator for a short.

 

[PetesPonies]

Most times the problem is with the battery. I know you just drove it,m but if the connections were not good, no charging was going on while you were driving it. So do this, remove terminals and clean them well. Then reinstall. Charge the battery over night, slow charge. Then see how it reacts tomorrow. YOu can get drains from the alternator, but they are rare. That can be found by letting it sit over night with the alternator disconnected. If no drain in the morning, you have your culprit. A weakened battery will not have the amps available to turn a hot starter. heat soak in a starter adds to the resistance, meaning more amps are necessary.