What the hell is on the room fuse besides Dome light and radio and such? This circuit with fuse in kills my battery over night. Dome light is off, Unplugged radio, checked defrost. Still have a draw. Draw goes away with the BTM1 Fuse removed or Room Fuse.

 

what year miata...

 

Oh yeah sorry, its a 99

 

My 97 had a trunk light that never shut off. It took a few weeks before I realized what was killing my battery

 

alarm?

 

The Room Fuse is 10A and downstream from BTN1 Fuse 20A. So BTN1 is not the culprit and your problem is downstream from Room. Defrost does not go through Room.

In stock condition Room powers all of the below and connects to each with a Blue/Red wire:
Data Link Connector (OBD2)
Instrument Cluster (Pin 1F Microcomputer (Odometer) and Key reminder)
Interior Light
ECU (Pin 1A - "keep alive")
EC-AT Control (Automatic Transmission)
Power Antenna (Pin B)
Audio System (Pin 1C memory/clock)

 

No, no alarm. Tried everything I think but replace the battery at this point. Before this crap happened, the battery went dead (i guess) because of something I did. I installed a EBC controlled by MS3 and somehow the EBC stayed powered up over night and the next morning battery was completely dead. This was the first time I had this problem. I used switched power from the ABS fuse location for the EBC. Didn't think it mattered since I don't have ABS. But I have since gave it its on power source with a relay in the circuit. But it didnt help any.

 

Well i have found out what is making my battery die. After replacing the battery and along the way trying to fix a charging problem, i have also replaced the alternator. Well turns out, my alternator is getting power from the 5v V-REF white/red wire on the 2 pin connector with the key OFF !! 3.5 volts to be exact, which is causing a 2.5 amp draw all the time with key off. And thats not all, some of the other evap solenoid wires of the same color that are a 12v signal power wire, have 4.5 volts with key off. Lists of components replaced : Ignition switch, Main Relay, Alternator, Battery, Checked all Grounds. I have power bleeding over from somewhere and i dont know where. I also have a Rev BUilt MS3. Any IDeas?

 

So i found out that if i unplug the 22 pin connector from my rev built MS3, it stops feed voltage to my alternator............. WTF Gives, when i turn the ignition off, i was under the impression that it was supposed to turn power to MS off. I didnt think it MS3 had KAM?

 

Found it.....Somehow the DIY Autotune EBC is causing my problems. If I unplug the ebc from the db37 connector, my draw goes away and I no longer have voltage at the 2 pin connector on the alternator. Funny thing is the damn thing still worked.. im puzzled