No Power, No Start (very sudden, w/ good battery)

[timmytimtim]

I drive a 2000 4WD V6 4Runner as a secondary/fun vehicle. Stopped for gas, cut the engine off, but left power on to listen to radio. Went to crank and lost all power the moment I turned the key. There is amost no power in ACC key position or any on/crank key position. No dash gauges (except for battery warning light), turn signals, power windows. Turning on the headlights causes a constant clicking noise and the headlights barely brighten then go out at a quick, constant pace. The green LED around the ignition key does light still.
Towed her home and spent the afternoon checking fuses and connections.

Here is what I have tried thus far:

Swapped in a known-good battery
Removed the wiring to both the alternator and starter to rule out a short on those lines- no change in lack of power in ACC key position.

I checked the voltage between ground post of battery and the AM1 and AM2 fuses. At power-in side of these fuses, 12V. I replaced the 40A AM1, 30A AM2, 10A GAUGE, 10A IGN, and 7.5A STA fuses just to be sure, to no avail.

What could cause such a sudden total loss of power? Is it possible that the ignition switch itself is bad? Could that impact the accessories such as windows, etc.? The battery terminals are quite new and tight, and I did a Big Three wiring upgrade that treated me well for some months now, and made no changes recently.

 

[brillo_76]

I drive a 2000 4WD V6 4Runner as a secondary/fun vehicle. Stopped for gas, cut the engine off, but left power on to listen to radio. Went to crank and lost all power the moment I turned the key. There is amost no power in ACC key position or any on/crank key position. No dash gauges (except for battery warning light), turn signals, power windows. Turning on the headlights causes a constant clicking noise and the headlights barely brighten then go out at a quick, constant pace. The green LED around the ignition key does light still.
Towed her home and spent the afternoon checking fuses and connections.

Here is what I have tried thus far:

Swapped in a known-good battery
Removed the wiring to both the alternator and starter to rule out a short on those lines- no change in lack of power in ACC key position.

I checked the voltage between ground post of battery and the AM1 and AM2 fuses. At power-in side of these fuses, 12V. I replaced the 40A AM1, 30A AM2, 10A GAUGE, 10A IGN, and 7.5A STA fuses just to be sure, to no avail.

What could cause such a sudden total loss of power? Is it possible that the ignition switch itself is bad? Could that impact the accessories such as windows, etc.? The battery terminals are quite new and tight, and I did a Big Three wiring upgrade that treated me well for some months now, and made no changes recently.

What the voltage at the battery post with the terminals on??


Does this voltage drop when you turn the key to acc?

Do you have absolutely no power or just no starting. Will starter turn and spin.


Does your vehicle have keyless entry and a engine immobilizer? [ alarm with a fob] a Toyota red light that says Toyota security on it?


To answer your question can the acc on the key go bad. The answer is yes. I lost the start contacts in my Tetanus 1. So my rig would not start.

Those contacts are easy to change as they plug into wiring and the back of your ignition key.


Mostly when the key contacts goes bad if you wiggle the key once in a while it will make contact.




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[jgue467]

Did you check the battery post connections, most likely one is loose for it to occur 'suddenly' and with a 'good' battery (but check it's voltage is connections are good - has to be at least 12.7). Luck and enjoy that part-time Runner. :cowboy:

 

[timmytimtim]

Thanks very much for any insight you can provide. I'll answer all your followup questions below:

Voltage across the posts is currently 12.3V. When this first occurred earlier in the day I believe the voltage read around 12.4V. Turning the key to ACC position does not change the voltage at all.

I have no power to windows, power locks, aux outlets, or clock in the ACC key position or any other key position. When turned to start position, the starter does not turn either.

The previous owner had a keyless entry unit installed (model: Directed 4x03) which I never used or made adjustments to. It is currently blinking a red indicator light. There is no evidence of a dedicated immobilizer from my searching, but I do have the Toyota security light on the panel near the driver's side fuse panel. It is currently unlit.

I just tested voltage between ground and the ACC pin of the ignition switch wiring harness. Voltage rises from about 3.4V at the ACC pin to 12.2V when key is turned to ACC position. Would this suggest that the contacts are fine?

 

[spartacus]

It's got to do something with the aftermarket entry or Alarm system. There was thread on here with your symptoms and after a ton of trouble shooting and throwing parts at it. The owner finally took it in and had the old security system removed and everything was well.

 

[brillo_76]

Thanks very much for any insight you can provide. I'll answer all your followup questions below:

Voltage across the posts is currently 12.3V. When this first occurred earlier in the day I believe the voltage read around 12.4V. Turning the key to ACC position does not change the voltage at all.

I have no power to windows, power locks, aux outlets, or clock in the ACC key position or any other key position. When turned to start position, the starter does not turn either.

The previous owner had a keyless entry unit installed (model: Directed 4x03) which I never used or made adjustments to. It is currently blinking a red indicator light. There is no evidence of a dedicated immobilizer from my searching, but I do have the Toyota security light on the panel near the driver's side fuse panel. It is currently unlit.

I just tested voltage between ground and the ACC pin of the ignition switch wiring harness. Voltage rises from about 3.4V at the ACC pin to 12.2V when key is turned to ACC position. Would this suggest that the contacts are fine?

12.4 volts really seems on the lower side for a battery. Maybe it's super cold in your area.

If you are seeing the same voltage at the acc pin on as your battery has then I say the contact working.

Battery voltage is 12v to 13.8v. I would think your battery would have a higher voltage if fully charged.

I have to see were mine is sitting at as it is winter and was 20 degrees this morning.



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[brillo_76]

It's got to do something with the aftermarket entry or Alarm system. There was thread on here with your symptoms and after a ton of trouble shooting and throwing parts at it. The owner finally took it in and had the old security system removed and everything was well.

I am leaning more with [MENTION=50279]spartacus[/MENTION] on this one. Especially if it's an aftermarket keyless entry and alarm system. Can you unplug the aftermarket system and see what you have.




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[timmytimtim]

Thanks guys for your responses. I've been out with the 4Runner this morning, and want to update with what I've found:

First, I pulled the steering wheel cover and AC ducting to give better access to the wiring of the aftermarket keyless entry. All main lines from ACC, ignition, and starter seem to be tapped only, like a T splice. I plan on removing the system and the splices anyway and will inspect the wiring for damage.

I considered again that this might be a battery issue, so tried two things. I cranked the Sequoia up and linked up jumper cables to the 4Runner. To my surprise, bringing the key to ACC position gave me power, so I immediately rolled up my windows (and removed the trashy plastic I had covering the open windows lol), then attempted a crank. This brought about the exact symptoms that left me stranded originally. No accessory power, no start, even with jumper cables running off the Sequoia. Just for kicks I removed the 4Runner's battery altogether and popped it on the charger. Then I swapped in the Sequoia battery, left the starter positive cable UNconnected, and brought the key to accessory position. Sure enough, clock, radio, windows all worked. Hooked up the starter cable and tried to crank... a single loud click from what sounded like the passenger side engine bay (the side is iffy, but definitely up front), and then all power is cut. I tried removing the starter cable, disconnecting the battery, and cannot get power to accessory again.

In summary, I can get power to accessory, but a crank attempt cuts all power to the vehicle. What has me the most stumped is that I cannot determine what "resets" the accessory power. It is as if a crank attempt disconnects all power until a reset has occurred, but I cannot replicate exactly what that reset is. After my most recent attempt, I removed the starter cable, I disconnected battery negative, I removed positive and negative cables, and I touched positive and negative cables together (disconnected from battery) as I read that this resets ECU. None of this worked so I left the battery entirely disconnected and came inside to write this.

My next attempt will be to pop the charged 4Runner battery back in, disconnect the aftermarket keyless entry system, confirm accessory power with starter cable disconnected, and then reconnect the starter cable for a crank attempt.

Any idea what the loud click I hear at power disconnect might be?

 

[brillo_76]

Check for a dead short in your stater. With a multimeter set to continuity. Make your lug that goes to the battery to ground isnt.

Also what's the resistance reading on the starter. Its looking as if the starter may to shorted.


Can you turn the crankshaft pulley with a wrench and engine turns freely.





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[timmytimtim]

Got her running! Ran the truck for a few minutes, shut it down, cranked again, ran for a little. I repeated this several times just to make sure that it wasn't a fluke. Thanks to everyone who responded and all suggestions received. Having a community like this one definitely helps keep me sane and confident when working through issues on the Runner. One of the main reasons I will continue owning one as long as I'm kickin'.

Here was my process:

What got me on the right track was running new grounds to chassis and upper intake plenum. I had a spool of thick 2AWG welding cable and lugs, so I made up some temporary cables to rule out bad grounding. Ran them from the battery negative terminal to a bolted spot on the upper intake as well as a bare spot on the chassis. After doing this, I was still experiencing a single click when the key was turned to start, but accessory power would NOT drop out.

Side story about my grounding issues: When my stock alternator died on me months ago, I replaced it with a CS-144 alternator from the 1995 Cadillac Deville (search for "Doc's CS144 alternator upgrade" for details). While doing the replacement, I removed the stock engine ground cable as it was gunked up and nasty. I ran a new ground from the alternator to the battery and from battery to the chassis. Excited to test the new alternator, I cranked her up and she ran like a dream- my alternator issues were gone. Even WITHOUT a new engine ground, the combination of alternator ground and chassis ground had me running good for MONTHS until now. It is interesting that grounding seems to have surfaced as an issue only now. I wonder if it may be the cold, or a higher amp draw.

To get the 4Runner cranking, I ran another new 2AWG cable from battery positive to the starter. The original was nasty and gunked up, so I figured a replacement was in order either way. After running this new starter cable, she fires right up.

I'm leaving this here in detail in case someone comes across the same symptoms. The following would all be on the top of my list to check for anyone with these symptoms:

Battery health. Try a jump-start, try swapping in a known good battery.
Fuses. Check your main ALT fuse, your AM1 and AM2 fuses in the engine bay fuse box and make sure they aren't blown.
Ignition switch. Your ignition switch should be passing 12V through it's main connector whenever you turn key positions to the starter and accessories
Main wiring/Grounds. Turns out this was my issue- I did not have quality grounds and the electrical pathway from the battery to the starter and back simply was not good. In my case, there were no intermittent issues as warning signs.

 

[brillo_76]

Glad you got it running and found the grounds were your issue.

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[pluton]

It's a good feeling to have solved a problem. But---Why did you drive around for months w/o an engine ground cable?

 

[phillipfym]

hey man just wanted to say you’re a Godsend. Seriously. Same thing happened to me to a tee, and ended up being a loose ground wire on my battery terminal. Thanks to your post it put me in the right direction after just buying my ‘00 2 days ago and was 45 minutes out from my house. Thank you so much, sincerely.

God I love Toyotas and the even more the people who own them.

 

[thebarber]

Another thank you to the OP. The ground SEEMS likely my issue as my power came back when I wiggled the positive battery connector tonight.