Hey all,
I have a 98 Toyota 4Runner (4Cylinder) with 275k miles on the odometer. I believe there is a voltage leak in the car somewhere. We’ve been trying to find and fix the problem for the past year. It’s just been sitting in the driveway for a few months. We scanned the car through OB2, and it says there isn’t anything wrong.
We’ve ran through multiple batteries, replaced the alternator a few times already. At this point we are just stumped on what to do. The factory stereo has been out for a couple of years, maybe it’s leaking there? I don’t know. Any help or areas to look at or fixes are much appreciated.
Thank you!
Voltage doesn't leak, it goes to ground. You need to disconnect the negative battery cable, connect a test light from the negative battery post to the negative cable. If the test light is on, you have a parasitic draw pulling your battery down. Start pulling fuses one at a time until the light goes off and you have then found the circuit with the problem and you can go through it to see what is shorting or grounding and killing your battery. Likely suspects are the wiring that goes through the door jambs into the door. These get bent and compressed a lot and often cause these types of problems. First, though, identify the circuit causing the problem(s) as described above.
There are many videos on YouTube on this topic, here is one from Scotty:
Use an ammeter to check how much current the car is drawing with everything turned off. Typically it would be in the range of 25 to 50 milliamps. If it's higher remove one fuse at a time and recheck to try finding the faulty circuit.
