Finding a draw on the battery

[KBScobravert]

Background: Came home on Friday from the HRPT and left the car outside overnight. Next day I went out to swap tires and take her for a cruise. Nope, dead battery. Set the battery on the charger for a couple hours. Go to restart it and where as it fired up fine and set into an idle quickly, it would not rev up through the RPMs smoothly. Felt like it was on a two step.

I limped it into the garage and I pulled the alternator and had it tested. It passed but that is all their report said, passed.

Put it on a charger for the full day. Pulled the charger and let it sit. Battery took 16.7v and held it for 12 hours unhooked from the car. (alternator was not in the car)

I put the alternator back on. Checked the battery again 16.00v and hooked it up. Let the car sit for another 12 hours. Ugh, 9v left in the battery. I checked the alternator and it is HOT. Not too hot you can't keep your hand on it but very HOT.

Lastly the battery light is on on the dash, key out so nothing should be powered up.

Any ideas? Battery drains when the alternator is hooked up and ONLY when the alternator is hooked up. But battery passes a bench test for amps output.

Is it time for a new 200amp alternator?

[SS Junk]

Anything aftermarket on the car that uses power?

[KBScobravert]

Anything aftermarket on the car that uses power?

Not unless the key is on. The whole damn car is aftermarket unfortunately.

[SS Junk]

You need to put a volt meter on the negative battery terminal and start pulling fuses. If you're not familiar with this there are many how to's. Google 'parasitic drain'.

[BlueCoupeRedVert]

I bet you cooked your altinator.

[KBScobravert]

I bet you cooked your altinator.

That is what I am thinking. Otherwise why would the alternator be getting HOT with the key off.

[BlueCoupeRedVert]

That is what I am thinking. Otherwise why would the alternator be getting HOT with the key off.

The regulator could be jacked. Might put out good power for charging, but shorted just enough to cause a drain..

[KBScobravert]

The regulator could be jacked. Might put out good power for charging, but shorted just enough to cause a drain..

Oooh I have a spare regulator I could tryout.

Sent from my SAMSUNG-SGH-I727 using Tapatalk 2

[DON SVO]

Oooh I have a spare regulator I could tryout.

Sent from my SAMSUNG-SGH-I727 using Tapatalk 2

Swap regulator, perform a draw test like SS Junk posted.

[BttleFedC10]

Background: Came home on Friday from the HRPT and left the car outside overnight. Next day I went out to swap tires and take her for a cruise. Nope, dead battery. Set the battery on the charger for a couple hours. Go to restart it and where as it fired up fine and set into an idle quickly, it would not rev up through the RPMs smoothly. Felt like it was on a two step.

I limped it into the garage and I pulled the alternator and had it tested. It passed but that is all their report said, passed.

Put it on a charger for the full day. Pulled the charger and let it sit. Battery took 16.7v and held it for 12 hours unhooked from the car. (alternator was not in the car)

I put the alternator back on. Checked the battery again 16.00v and hooked it up. Let the car sit for another 12 hours. Ugh, 9v left in the battery. I checked the alternator and it is HOT. Not too hot you can't keep your hand on it but very HOT.

Lastly the battery light is on on the dash, key out so nothing should be powered up.

Any ideas? Battery drains when the alternator is hooked up and ONLY when the alternator is hooked up. But battery passes a bench test for amps output.

Is it time for a new 200amp alternator?

This happened to me yesterday on the way home, truck dropped down to 9 volts while on the highway, stopped by o'reillys and had the battery test with a meter and it was good, radio off and electric fan off and it was on turning 30amps. took it home took the alternator off and it was hot! Went and had it tested 3 times and it passed. So i just went ahead and bought a new alternator and its fixed. Even though the alternator passed the test it was still cooked. Weird..

[KBScobravert]

This happened to me yesterday on the way home, truck dropped down to 9 volts while on the highway, stopped by o'reillys and had the battery test with a meter and it was good, radio off and electric fan off and it was on turning 30amps. took it home took the alternator off and it was hot! Went and had it tested 3 times and it passed. So i just went ahead and bought a new alternator and its fixed. Even though the alternator passed the test it was still cooked. Weird..

Thanks.

I have a regulator that I am going to swap tonight and charge the system then plug it all in. Letting it sit overnight otnight should tell me if I am in the right direction.

If it is/was the regulator, I still may look at a new and higher amp alternator. With the amount of electronics on the car it could not hurt.

I just wished I could get the alternator to move even an 1" from the Turbo. I have another alternator bracket that I may try to slot the 3 mounting holes and see what kind of room that gives me.

[white88]

I posted in your thread on the Corral but since it's been on the fritz today I'll post here too. I have an extra 3G alternator laying around if you want to try it out.

[KBScobravert]

I posted in your thread on the Corral but since it's been on the fritz today I'll post here too. I have an extra 3G alternator laying around if you want to try it out.

Thanks Chris. I have a spare that I pulled a couple weeks ago from the pick and pull just to have around. If swapping the regulator fixes it, and I will know pretty quickly after hooking the battery back up if the alternator stays cool, I am going to drive it as is and buy a 200amp in a few weeks.

[white88]

Thanks Chris. I have a spare that I pulled a couple weeks ago from the pick and pull just to have around. If swapping the regulator fixes it, and I will know pretty quickly after hooking the battery back up if the alternator stays cool, I am going to drive it as is and buy a 200amp in a few weeks.

No problem, if you change your mind and want a spare laying around let me know.

[JPM]

regulator

Just went thru this on my truck. It charged fine as I drove around but when I parked it, it would drain both batteries in about four hours. I could charge it and start it and do the same thing. After charging and diconnecting the alt overnight, it started right up in the morning. The contacts in the regulator welded themselves together after a high current situation and it drains the battery when sitting. Sounds like you have the same thing. I just went and bought a new alt and have had no trouble since. Good luck.