Hey all, new to the forum. I got a 96 SR5 3.4l with a little over 370,000. Bought it for 1500 about 6 months ago.

Car has been running great over the past 6 months. Starts up and drives great. Went to crank her over 2 days ago, and its totally dead. So i got a jump and went about my business. next day, dead again. Now i check the voltage and the battery is at 2.85v. I jumped it again and put a multimeter to it. Alternator is charging fine (14.55v when running). Battery is still good, had it deep cycled and its holding at 12.5v. At this point i know i have a parasitic draw. I hooked up my multimeter in series and.... nothing. No draw at all when the car is off. I had a mechanic friend looking over my shoulder when i was doing this and even he couldnt explain it. I proceeded to pull and check all the fuses. All were good. Where do i go from here?

Also, i dont know if they could be related, but there have been some strange electrical occurrences. 1.) the dome lights dont come on when the doors are opened. Fuses are good, lights work when manually switched on. 2.) The cruise control shuts off when you turn off the AC. 3.) More recently the headlights stay on even when you flip the headlight switch to the off position. The only way to get them to turn off is the turn the car on/off while screwing with the light switch. 4.) The cruise control works 50% of the time.

These kind of issues lead me to believe that there is a logic problem somewhere in the computer. Could the ECU be to blame, or is there a control module responsible for these systems?

@TheDurk might be able to give you a hand. He’s very knowledgeable about electrical and ewd.

Inspect your wire harness, looking for abrasion and potential shorts; which would explain an intermittent parasitic drain.

Also, how new/good is that battery?

If the car battery is dying overnight and your meter reads 0 amps, either A) your meter fuse is blown, or B) your battery is blown. There should be 30-50 mA IIRC even when off for memory functions.

^^^What he said. Yeah, check that meter or try another one.

Also, load test that battery. Holding voltage is meaningless. Inspect and clean battery terminals and fender ground point.

Report back.

My question would be if the problems were occurring before the dead battery started occurring?

There is always at least a 20 milliampere draw on the circuit.

See if the alternator is hot, like really hot after running. I would be curious to know if it is original one.

Thanks for all the speedy replies.
The battery is newer, bought about 6 months ago. I just checked the internal fuse on my meter and its still good. Am i not wiring my meter in properly?: Disconnected negative battery terminal then clamped probes to terminal/wire and meter set to DCA. Is there something im missing? The problems detailed above have been going on since i bought the car (also forgot to mention that the rear defroster doesnt work). The alternator was replaced by the previous owner last year.

I dont have a whole lot of time today, but tomorrow i'll have the battery load tested, clean the grounds (how many other ground locations are there excluding the fender ground right next to the battery?), visually inspect the harness, check the alternator for excessive heat when running and also do a voltage drop test across all the fuses.

IIRC from my full-time wrenching days, you need to have the meter set, touch & hold the probe to the negative clamp, then remove the clamp from the battery, maintaining contact with the probe to read milliamp draw. Have someone else pull fuses one by one while you watch the meter to identify which fuse is associated with the drain.

It should be reading higher than 0 which makes me think you have a bad meter (possibly blown fuse) or you are not hooking it up right.

Most multi meters require you to move the red probe to the "socket/spot" on the meter that is used for measuring amps.

You then disconnect the positive battery cable and put the red probe on that cable. The black probe then goes to the positive side of the battery. You should be seeing 20-50ma if everything is good.

Make sure while you are doing this that you do not use anything in the truck that pulls a lot of amps or you will pop the fuse in the multimeter. Also, make sure you do not switch it back to checking volts while it is setup in this configuration or you'll blow the fuse in the multimeter.

I like to use those little alligator clip jumper wires so I can leave the multimeter hooked up while pulling/checking fuses and still be able to see it.

A battery in good working condition won't drop to that low of a voltage reading overnight with just a parasitic draw. Even a nominal draw wouldn't give such a low reading. Have the battery tested properly, or swap in a known good battery. Also try a different meter for the parasitic drain testing, it is not possible to have a ZERO amp draw on a 3rd gen.

3V spells bad battery to me.

If the alternator is a store brand rebuilt, it can go south quickly. These 4runners like their OEM, or at least Denso parts.

The fuse for the dome light circuit good? My guess is that there is a draw on that circuit. Touched the rear defroster, etc in the last couple of days?

I believe he is right, your battery needs to be load tested. I've killed my battery a few times and it would read more than 3V. More like 8-9.

However, on my old '91 it would die if I left the headlights on for 30 minutes. Voltage test always went back up to 12V but the battery was indeed toast and couldn't hold a charge.

Agree that your multi-meter should id the issue (if you are drawing significant amps, however, it will blow the fuse or if not fused, fry the meter) and you should test the battery but the fact that headlights are still on after truck turned off caught my eye. I would investigate the headlight relay...when it has failed/stuck, some folks hear a tick, tick, tick coming from their main junction box when the car is off and battery still has juice. If your battery is draining each night, you could pull that relay and see if the battery drain still occurs. Replacing that relay is cheap.....

Buckaroo

As to all the electrical weirdness issues, I pretty much disregarded those. Until you have surety of a solid battery and a robust charging system, they don't mean much, unless you can tie them to a parasitic drain. A weak battery is like a cancer to an electrical system, and weird stuff happens all over. Get the battery/alternator situation straightened out, and then see what happens. First things first.

Failure in the auto-shutoff module in the speedo and the stalk are also causes of headlights stuck on. I'd say both are more common than head relay failure.

sorry for the delay (been sick these last few days). Finally have some updates. The battery was toast. Failed load test, thankfully it was still under warranty. I also went out and bought a nicer multimeter. Hooked up the battery and drove it around a bit then felt the alternator as mentioned above. No excessive heat and still appears to be charging correctly.

This time when i hooked up the multimeter im getting a draw, but its a lot less than what i was expecting. With everything off, doors closed, etc, etc, i was getting .071A. When i pull the ECU-B it drop down to .015A. Additionally, i lose another .01A when i pull the DOME fuse (15A fuse under the hood. Is this the interior dome lights? i would have expected this fuse to be in the cab). I cant track down where the remaining .005A is going.

A few other observations:
When the battery circut is broken and reconnected the draw jumps from .33A to .45A then down to .1A and eventually lands on .071A. Does that sound about right? It seemed like rather excessive draw for an initializing stage.

Im starting to think that my issue is more related to this headlight problem. What parts should i test next? Headlight relay/signal stalk?