Hi everyone, I recently purchased a 2001 LX470. I have been lurking here and learning from you guys for the last 2 months, y'all rock 
This is my first post on this forum and it's a bit of a doozy. Sorry in advance for the long read, but I could really use some pointers on troubleshooting this.
For the first month of ownership, I had no serious parasitic drain issues with the battery, the LX always started up on the first try, even after not driving her for a few days. But ever since I changed my power antenna (~2 weeks ago), the battery has started to die every 1-2 days. I assumed the drain was coming from the antenna motor... a bunch of water came out of the motor when I pried the plastic sides apart, and the battery started draining overnight, right after that job. But I unplugged the antenna relay behind the glove compartment, and the battery still dies, even with no power going to the antenna. So unless I'm missing something... correlation is not causation, in this case.
Since then, I have done a parasitic drain test by attaching my multimeter between the battery and power lead, to measure the amps it's drawing. Generally, I'm getting ~300 mA of draw, with the key out of the ignition and the doors locked. Interestingly, when the doors are unlocked, the LX draws 1-2 amps, which seems crazy to me. But even after a half hour, the draw was that high. I've read these vehicles are thirsty for electricity, so maybe thats normal or maybe it's related to the issue. I'm not sure.
But with the key out of the ignition and doors locked, I also get parasitic spikes up to 7 amps. And I'm not sure what's drawing that amount of power. Pulling individual fuses never caused the 300 mA of draw to drop any lower... based on what I've read in this forum, 50-100 mA is "normal" from the factory. I can try pulling the fuses again and see if the spikes go away, since it's the spikes that are really killing my battery. But this would be a very slow and long test, the spikes are a bit random, and I have a few other clues that might narrow this down.
1. At AutoZone, the Starter failed their diagnostics test. The only info I have from this test is that the "Voltage Under Load" was 12.2V, which sounds fine to me. And the Current Draw was 200 Amps. I guess that's low, but I haven't looked up what the factory starter is supposed to draw. According to the guy who ran the tests, the battery tested at 99% health. The alternator and voltage regulator also passed. I've read starters can cause parasitic drain, so maybe it's that, but there is another obvious problem that's got to be related to the draining issue.
2. When the car is off, I get a heartbeat thumping sound over the speakers. The LX has made this heartbeat sound since the day I bought it, before the battery drain was an issue. The heartbeat sound never stops, even when I pull the radio fuse, and I think it's gotten louder since I bought the LX. I'll come out to the LX in the morning and hear it thumping through the windows, while the battery is on its last legs. I've pulled all the fuses in both boxes and I don't think it's ever stopped the thumping, although I can double check that. This is super strange to me. When I bought the LX, I assumed the Mark Levinson amp was failing, or maybe the head unit... I get an error code when trying to play a CD, so the head unit has problems. But I don't know why the heartbeat sound would continue, even when the radio fuse was pulled.
And just to confirm, I am not able to turn the stereo on unless the key is in ACC or IGN. I've pulled the stereo out of the dash and all the wiring looks factory... there's no splicing or other tinkering back there. I do know the previous owner swapped out the speakers. I'm not sure what he installed, but I think the ML speakers are 2 ohm and most aftermarkets are 4 ohm. I don't believe this could cause the thump, but maybe it's related... ?
I'm going to be replacing the head unit soon, so I can eliminate that variable. I was also thinking about unplugging the ML Amp and see if that solves the issue, I just need to find the time to pull the passenger seat. Unless there's an easier way... I figured the amp would be connected to the Radio fuse, but I still get the thumping sound.
Any thoughts or feedback on all this? Or other suggestions for troubleshooting? Is it possible the starter is leaking power and the amp is somehow picking it up and thumping the speakers? TIA
This is my first post on this forum and it's a bit of a doozy. Sorry in advance for the long read, but I could really use some pointers on troubleshooting this.
For the first month of ownership, I had no serious parasitic drain issues with the battery, the LX always started up on the first try, even after not driving her for a few days. But ever since I changed my power antenna (~2 weeks ago), the battery has started to die every 1-2 days. I assumed the drain was coming from the antenna motor... a bunch of water came out of the motor when I pried the plastic sides apart, and the battery started draining overnight, right after that job. But I unplugged the antenna relay behind the glove compartment, and the battery still dies, even with no power going to the antenna. So unless I'm missing something... correlation is not causation, in this case.
Since then, I have done a parasitic drain test by attaching my multimeter between the battery and power lead, to measure the amps it's drawing. Generally, I'm getting ~300 mA of draw, with the key out of the ignition and the doors locked. Interestingly, when the doors are unlocked, the LX draws 1-2 amps, which seems crazy to me. But even after a half hour, the draw was that high. I've read these vehicles are thirsty for electricity, so maybe thats normal or maybe it's related to the issue. I'm not sure.
But with the key out of the ignition and doors locked, I also get parasitic spikes up to 7 amps. And I'm not sure what's drawing that amount of power. Pulling individual fuses never caused the 300 mA of draw to drop any lower... based on what I've read in this forum, 50-100 mA is "normal" from the factory. I can try pulling the fuses again and see if the spikes go away, since it's the spikes that are really killing my battery. But this would be a very slow and long test, the spikes are a bit random, and I have a few other clues that might narrow this down.
1. At AutoZone, the Starter failed their diagnostics test. The only info I have from this test is that the "Voltage Under Load" was 12.2V, which sounds fine to me. And the Current Draw was 200 Amps. I guess that's low, but I haven't looked up what the factory starter is supposed to draw. According to the guy who ran the tests, the battery tested at 99% health. The alternator and voltage regulator also passed. I've read starters can cause parasitic drain, so maybe it's that, but there is another obvious problem that's got to be related to the draining issue.
2. When the car is off, I get a heartbeat thumping sound over the speakers. The LX has made this heartbeat sound since the day I bought it, before the battery drain was an issue. The heartbeat sound never stops, even when I pull the radio fuse, and I think it's gotten louder since I bought the LX. I'll come out to the LX in the morning and hear it thumping through the windows, while the battery is on its last legs. I've pulled all the fuses in both boxes and I don't think it's ever stopped the thumping, although I can double check that. This is super strange to me. When I bought the LX, I assumed the Mark Levinson amp was failing, or maybe the head unit... I get an error code when trying to play a CD, so the head unit has problems. But I don't know why the heartbeat sound would continue, even when the radio fuse was pulled.
And just to confirm, I am not able to turn the stereo on unless the key is in ACC or IGN. I've pulled the stereo out of the dash and all the wiring looks factory... there's no splicing or other tinkering back there. I do know the previous owner swapped out the speakers. I'm not sure what he installed, but I think the ML speakers are 2 ohm and most aftermarkets are 4 ohm. I don't believe this could cause the thump, but maybe it's related... ?
I'm going to be replacing the head unit soon, so I can eliminate that variable. I was also thinking about unplugging the ML Amp and see if that solves the issue, I just need to find the time to pull the passenger seat. Unless there's an easier way... I figured the amp would be connected to the Radio fuse, but I still get the thumping sound.
Any thoughts or feedback on all this? Or other suggestions for troubleshooting? Is it possible the starter is leaking power and the amp is somehow picking it up and thumping the speakers? TIA
