Starts when key turned to ON

Last night driving my 07 Sequoia (4wd Limited, 182k) on the Interstate in rain, my dashboard lights flashed intermittently a few times like a loose connection and then went out. The Speedo, tacho, and all the other gauges work as do the lights for the seat belt, gear position, ignition, etc. The odometer is blank, and the lights in the analog needles and the background lights are off (can’t see the speed at night). The car also starts as soon as the key is turned to the ON position without having to turn it to the crank position.
It happed once before a couple of years ago, and I disconnected the battery overnight and everything was good when I reconnected the battery and had worked fine since. Now disconnecting overnight did not help either.
I’ve too many things that I can think of that could go wrong. Anyone with any helpful pointers, or experience with this issue would be a big help. Thank you for reading my long post.

 

It would help to know if you've ever had an alarm, either dealer-installed, or aftermarket. Some dealers quietly installed the SECURIKEY+ and KARR systems without telling owners.

From our community info thread, "Electrical stuff ... and keys" section: https://www.tundras.com/threads/so-you-wanna-buy-just-bought-a-1st-gen-tundra-eh.115928/

• These trucks usually don't have a ton of other electrical issues. Hidden corrosion inside the battery/alt cables happens. Sometimes, a couple thousand miles after timing belt changes, people will have startup issues because the crank position sensor wasn't properly tucked away and gets rubbed by a belt (pic), correct routing info here. There's also a similar problem with camshaft position sensor under the cam cover, where the belt will rub through (pics). There's the rodent issues mentioned earlier. Occasionally, water trails down harnesses into the ECM behind the glovebox (pics, pics), or the in-dash fusebox (pics & pics & pics) it happens a LOT. Many drain/vampire issues trace back to aftermarket add-ons whether the owner knows they exist or not - alarms as mentioned earlier, brake controllers, poorly installed trailer receptacles, those are some big ones.

While I'm tempted to believe you have a short in your ignition is the culprit, pay specal attention to the bolded fusebox bit up there, since it's hit so many people over the years, it's why we have so many pics of cases to share. I'd rule out water intrusion, especially if you're the kind of person who doesn't think it's important to fix cracked windshields, or if you've been victimized by the shit work Safelite is known to deliver.

 

Water. Make sure it's not getting into the cab and corroding your electronics.

 

What @KNABORES said.

 

Thank you for your responses. I don’t have any aftermarket stuff. I have the original Nav radio, and the original security system/key fob. I don’t have a cracked windshield, or suspect water intrusion. I’ve had a couple of rodent issues in the past where they once chewed my knock sensor wire under the intake manifold, and once some wires by the passenger door door-sill, but both were in the winter when the car was warm. It’s warm weather now (Atlanta) so I don’t think it’s the rodents. Moreover it happened while I was driving. I don’t have any starting problems either. It starts the instant I turn the key ON (even before it is cranked). I changed the timing belt 6 months ago, but again no starting or mechanical issues.

 

I’ll check first Water Intrusion that I’m maybe not seeing. I do have a sunroof. Anything in particular to check? The fuse box on the drivers side left by the feet? Should I remove the whole fuse box to check behind it? Looks good from the front.

 

Water intrusion happens frequently in the 1st gen. You don’t need cracks. And it’s often the main source of electrical gremlins, where circuits get fused together or separated.

That should be your #1 suspect. Look at the links I shared in bold. Seriously.

 

Yes. Remove. Unplug connectors. Look for green traces as shown in the pics.

 

Thank you, . I’ll check those and report back with any updates.

 

Definitely water intrusion a possibility.

Only because it was fairly recent do I recall the below thread dealing with basically same situation on an 06 Sequoia.

https://www.tundras.com/threads/06-...ion-and-no-lights-on-the-dash-cluster.156954/

 

Mine started in the on position as well, right after a bad windshield install... Never saw any water, but once it dried up, no more issues. I got a new windshield correctly installed afterward.

I also had window and lock issues but the dash was fine.

My first post on this site was about this issue.

Good luck