Car battery loses charge when on
 

I just recently experienced an issue with my 88 FC vert. Whenever I turn the ignition to ON, my battery gets drained, going from the 11.5-12.5 volts to as low as 4 volts. My car has been sitting for a few days because of this. Last time I tried turning it on, it kept cranking but wont turn over. I cranked the car many times that day, and I tried to start the car with other batteries and get it jump started but my car would just crank, do clicking noises, or nothing at all. I also switched out the alternator. When I turn the car off and/or disconnect the battery, the battery voltage starts going up. Before this battery drain issue, my car would crank and I would have to step on the gas pedal to get it started and it would smoke up due to blown water seals, but that's a separate issue.
Any ideas or theories as to why the battery drains when the ignition is turned to ON or when I attempt to start the engine?

Take your starter off and have it tested.

When you turn the key to ON the battery is going to drain, your turning all the electronics on with no alternator output to bring the battery back up. If you engine is rolling over and won't start, to me it sounds like your coolant seal issue and your no start issue ARE the problem right now

Unless the engine is rolling over slower than your used to?

i think hes trying to say is key off would be 12v and key to on the voltage drops. something draining the battery, possibly the alternator

my SA does a similar thing,
I turn the key to prime the fuel pump, tacho will sit a 12v for a few seconds then slowly drop off, a couple times it wouldnt crank unless I turned the key to off and back on again to get the volts back up.
but i think mine is the battery as it says 2009 on it lol and i don't know when the owner before me put it in.

but voltage is going to drop when you turn the key on and all the electrical in the car is coming on

or am I missing a HUGE part of the puzzle :dunno:

yes it would over some time, guessing the op saying is it draining too quick i guess.
something that could create a abnormal draw would be the rotor inside the alternator shorting out. as it get power when keyed on.

Yes, my battery gets drained quick. If i attempt to turn the key to ON, my voltages would start to drop. I even put my dads battery off his Honda crosstour onto my FC, turned to key to ON, and it read good voltages. As soon as i cranked the car, it would just crank and seem to lose voltage at the same time. When i would attempt o crank it again, it would just do clicking noises. After a while, the battery would just drain out and not click at all. Tomorrow, I will attempt to record my issue and post the link to the video on this thread, to exactly show the issue I am having. Thanks for the advice, I will attempt to get my starter and alternators, I have two, checked out tomorrow after recording the issue.

The battery terminal connections at the battery, fender (ground) and at the starter might be suspicious. You could also do an amperage drain test and see what's up as far as is there really a drain occurring and what is the source.

Link to video
 

This is the link to the video I recently posted regarding the battery issue. I didn't attempt to crank the car since I knew it wasn't going to be able to, but I will get the batteries recharged soon, and have the alternators tested, as well as the starter, as soon as I remove it.

https://youtu.be/GLDbNk-mlLI

Watched the video. You have a major drain. You need to start by isolating the different circuits to determine where this drain is coming from.

Check you grounds before doing anything. If you need to, run an extra ground.

If you disconnect the battery after the test you did in the video, does it measure ~12v or does it measure low like the reading? I'm surprised you haven't ruined a battery yet. With a drain like this, would would expect blown fuses possible a bad ground

Try removing each fuse one at a time, turn the ignition on like you did in the video, and recheck the voltage. If it still measures bad, replace that fuse and go on to the next. Might try the fuses on the drives side shock tower first. You might want to have one person turn the ignition on and the other measure. This way you can turn the ignition off faster and not drain the battery so fast.

The battery voltage measures ~12v after I disconnect it, I jut have to let the voltages go back up. I'll check the fuses, and I was also going to have the batteries recharged as well, ensuring they're not dead when I test the fuses.

Thanks for viewing, appreciate the feedback and I'll definitely keep an update, maybe make another video of me checking the fuses as well and upload it.

Update!!
 

So one battery kept getting drained but the other battery I tried held its charge, and kept its charge, and I was able to crank the car a few times. So now the presentable issue is that my car cranks but doesn't get the engine running. I will post a video on YouTube and share the link hopefully by later tonight or tomorrow.

You verify that you have spark, especially on the lead coil. If that goes well then you check if you have fuel.

Good to know it's not a circuit that is draining the battery. It doesn't take long with a rotary engine to drain the battery trying to start it. If the car doesn't start after a few try's, something is wrong. Continue cranking is only going to drain the battery.

Like satch, says, need to validate spark and fuel.