Guess will be best to start with what I've done. After discovering this, I fully charged the battery and left it unplugged overnight. To make sure it wasn't a dead cell in the battery. The battery didn't drop in voltage overnight. So then I hooked up the battery and unplugged the radio fuse, thinking maybe that was it. Went out today and the battery was dead again. Charged it up again, and brought out the mult-meter. Tested current draw on all the fuses in the fuse panel in the engine bay, and the fuse panel in the driver side dash. Nothing showed a current draw. To make sure I was doing it right I turned on the car and got a reading off the ECU fuses and turned on headlights etc... and got readings off each when they were turned on. So, I know I tested everything right. I'm at a complete loss here. Is there another fuse box somewhere? It's a 95 ST manual. Whatever is doing it is pretty severe. Drained the battery of over a volt in under 20 hours. All interior lights are set to off, and doors/hatch securely shut also. Any insight is much appreciated.
2001 Miata LS 5-speed
Cleaned the battery terminals and cable ends today, were pretty nasty looking. I checked today before cleaning and noticed it hadn't dropped as much like it did the other day. Only dropped less than a 1/3 of a volt this time.
2001 Miata LS 5-speed
your ECU and radio memory gots to eat!
Learned a lot in 10 years...I hardly log in anymore, last loginToday Sept 6 2019, and I was forced just to clarify a post. LOLIf you PM me and I dont respond, dont fret or cry. Im alive, better post your questions in the thread below, maybe I log back in2grfe Swapped...Why I chose the 2GR, before you ask read here...A great civilization is not conquered from without until it has destroyed itself from within.@llamaraxing in Instagram is the best way to find me. I hardly log here anymore.
check your interior lights, it happens to me when i leave them on.
Learned a lot in 10 years...I hardly log in anymore, last loginToday Sept 6 2019, and I was forced just to clarify a post. LOLIf you PM me and I dont respond, dont fret or cry. Im alive, better post your questions in the thread below, maybe I log back in2grfe Swapped...Why I chose the 2GR, before you ask read here...A great civilization is not conquered from without until it has destroyed itself from within.@llamaraxing in Instagram is the best way to find me. I hardly log here anymore.
Sorry I didnt see this thread sooner.
Make sure the door is shut and everything is completely turned off. Remove the negative battery cable. Set your multimeter to measure milliamps in DC. Connect one multimeter lead to the negative terminal of the battery, and the other to the negative battery cable. Remove fuses one by one until you find the circuit drawing the most milliamps. I believe 16 or .16 is considered normal, might wanna google that.
If you check the interior fuses make sure not to open the door. Your multimeter is not designed to handle full amps of load.
That's ok. I did the above, and didn't find anything. What threw me for such a loop. The battery terminals and cable connectors were corroded BAD. The terminals were almost black and the connectors were rusted all over. Why I didn't think to check that sooner I don't know.
2001 Miata LS 5-speed
I know, but something is draining it faster than it should. Has an aftermarket radio in it, going to examine all of that tomorrow to make sure. If you drive it everyday it's fine, but if you let it sit for a few days it's drained. Maybe was just a fluke, like I said when I checked this morning it barely dropped. Will check again tomorrow before ripping the radio out to inspect it and the wiring.
