Mystery. Zero DC power. Minutes later, full power back and started like normal.

[RogueWaive]

Good afternoon,

Daughter went to fire up her 2000 4Runner SR5 yesterday morning, came back in the house and said it wouldn't start. We sent her to school in Mom's Highlander. Mom went to try the 4Runner, said the electric door locks wouldn't work and no noise nor turnover when ignition attempted. Daughter reported same via text after she got to school.

So figuring our daughter must've left a light on, I grab the charger and head out to the driveway, open the door and the dome light comes on. I test the door locks and they function normally. Then the rig fires up like she has a brand new, OEM starter powered by a brand new pair of 1150CCA, fully charged AGMs.

The only thing that comes to mind is... there IS a negative disconnect on the battery (from when it was her grandpops' rig, that was no longer getting much use in his twilight years.) But I found it fully closed with no corrosion. All connections tight. And still... I wouldn't think a little corrosion would kill the entire 12V system... and a little dome light.

Obviously corrosion wasn't a problem because of all the cranking power that suddenly returned.

I would say maybe a fusible link could be loose or something? The only "jarring" to "fix" a bad connection would have been my dainty wife shutting the door after she confirmed it had no power.

Thoughts?

 

[JustTroItIn]

I recently had a similar issue. Had been driving for about an hour, and then made a quick stop. Had full power until I turned the ignition then everything went dark. I popped the hood to check connections, finding no issues. When I opened the door the dome light came back on and the truck started right up. My battery was pretty old so I replaced it, but not until the next day and two more starts later. The problem has not returned and it's been about a month.

 

[RogueWaive]

I recently had a similar issue. Had been driving for about an hour, and then made a quick stop. Had full power until I turned the ignition then everything went dark. I popped the hood to check connections, finding no issues. When I opened the door the dome light came back on and the truck started right up. My battery was pretty old so I replaced it, but not until the next day and two more starts later. The problem has not returned and it's been about a month.

Yeah I'm not super in love with crippling problems that just fix themselves before I can diagnose them. Especially when it comes to my wife or daughter's car.

But thanks for chiming in. Sort of nice to hear I'm not the only one. I guess misery does love company.

 

[JustTroItIn]

Especially when it comes to my wife or daughter's car.

I like to make sure mine struggle. Prepares them for life.




Yes, I'm kidding....a bit.

Good luck tracking it down. I'm doing the big 7 upgrade soon, and will be able to give her a better look over. I'll be watching this thread.

 

[Hungryhawk]

Two things come to mind:
1) a balky relay - does your model have a main relay?
2) does the ignition key have a security electronic chip in it? Were famly members using different keys? Their battery status?

 

[RogueWaive]

Two things come to mind:
1) a balky relay - does your model have a main relay?
2) does the ignition key have a security electronic chip in it? Were famly members using different keys? Their battery status?

No security chip. According to the Mrs., the door locks didn't work using the manual button on the inside door handle either.

I'll have to crack open that relay box.

Thanks!

 

[pluton]

The relay idea seems promising. A note on corrosion at the battery: If it has a FLA battery, there can be invisible-to-the-eye corrosion between the battery post and terminal clamp. AGMs don't outgas sulfuric acis as FLAs do, so if it has an AGM that's probably not an issue. Doesn't hurt to wire brush the terminals and clamps every so often anyway.

 

[RogueWaive]

The relay idea seems promising. A note on corrosion at the battery: If it has a FLA battery, there can be invisible-to-the-eye corrosion between the battery post and terminal clamp. AGMs don't outgas sulfuric acis as FLAs do, so if it has an AGM that's probably not an issue. Doesn't hurt to wire brush the terminals and clamps every so often anyway.

Just an FLA.

Thank you. I will brush the terminals and clamps, but... have you ever heard of this causing my issue? i.e park the car in the driveway the night before just fine. Zero power the next morning. Then full power mysteriously returns, on its own, within minutes. And then no return of the problem for the next couple days and counting?

 

[pluton]

Just an FLA.

Thank you. I will brush the terminals and clamps, but... have you ever heard of this causing my issue? i.e park the car in the driveway the night before just fine. Zero power the next morning.

I have had invisible corrosion that caused random switching between full normal start and no start. Not exactly the same as 'full DC power-no DC power', but worth eliminating as a possible cause or contributor to cause.

 

[brillo_76]

Everything dead. or everything low power mostly is at the terminals. Then all the sudden working without doing anything. Can be frustrating. If everything else has proper power levels and terminals not the issues. Next place is in the ignition system. Especially if your 180 to 250K with the original starter still in place. The contacts and brushes are warn out. Extremely common to act like that if the contacts are just about completely done.. If that is all good and it still randomly doesn't want to start. Check the ignition key contacts as they wear too but mostly a high mileage issue with the key contacts and a lot more on the rare side.

Its really a process of elimination until you find it. This is only ideas of what to be looking for.

 

[RogueWaive]

Everything dead. or everything low power mostly is at the terminals. Then all the sudden working without doing anything. Can be frustrating. If everything else has proper power levels and terminals not the issues. Next place is in the ignition system. Especially if your 180 to 250K with the original starter still in place. The contacts and brushes are warn out. Extremely common to act like that if the contacts are just about completely done.. If that is all good and it still randomly doesn't want to start. Check the ignition key contacts as they wear too but mostly a high mileage issue with the key contacts and a lot more on the rare side.

Its really a process of elimination until you find it. This is only ideas of what to be looking for.

Thanks, but it wasn't ignition. There was zero power. No dome light. No power door locks. No noise or instrument lights when they turned the key. No nothing.

Several minutes later, everything was working and the starter spun the motor like it was a new unit for a Peterbuilt.

Frustrating indeed.

 

[brillo_76]

Did you find the cause? As it will do it again until you do, probably when you least expect it too.

 

[RogueWaive]

Did you find the cause? As it will do it again until you do, probably when you least expect it too.

Yeah, believe me... that has been haunting me. As I mentioned earlier, I'm not a fan of crippling problems that just fix themselves before I can diagnose them.

No. I have not yet found the cause. I haven't had time to look into the relays yet. It's parked while my daughter is visiting family for spring break.

 

[brillo_76]

Yeah, believe me... that has been haunting me. As I mentioned earlier, I'm not a fan of crippling problems that just fix themselves before I can diagnose them.

No. I have not yet found the cause. I haven't had time to look into the relays yet. It's parked while my daughter is visiting family for spring break.

Everything dead along with the dome circuit.. It has to be at the terminals. Sometimes its right at the crimp spots too.. Could even be as simple as dirty lead terminals. Thais a complete open circuit when that happens. Narrows it down to the end point the terminals on the battery and the immediate area of ...;-)

 

[RogueWaive]

Everything dead along with the dome circuit.. It has to be at the terminals. Sometimes its right at the crimp spots too.. Could even be as simple as dirty lead terminals. Thais a complete open circuit when that happens. Narrows it down to the end point the terminals on the battery and the immediate area of ...;-)

So to go from working normally the afternoon before when parked...

to zero power the next morning...

to full starting power several minutes later... nor major jarring... just the wife closing the door... is terminals?

Seems odd to me. I've seen diminished starting power from corroded terminals. But never full... to zero... to magically full again like this.

But I'll check and clean the terminals. Never hurts.

 

[brillo_76]

I have loose terminals do that. I have a pile of rigs around and will through a battery in one to move it.. Just set the terminals on... Nothing move them a bit everything works.

Clean the terminals really good and put conductive grease on them. Clean the battery posts really good and put conductive grease on them put it together and see what you get...

Oxidation layer can build up in between the lead posts and battery terminals. Especially if they not super clean and covered in conductor grease. Can act just like someone pulled a terminal off. Then burn through the oxidation and conduct again.

 

[RogueWaive]

I have loose terminals do that. I have a pile of rigs around and will through a battery in one to move it.. Just set the terminals on... Nothing move them a bit everything works.

Clean the terminals really good and put conductive grease on them. Clean the battery posts really good and put conductive grease on them put it together and see what you get...

Oxidation layer can build up in between the lead posts and battery terminals. Especially if they not super clean and covered in conductor grease. Can act just like someone pulled a terminal off. Then burn through the oxidation and conduct again.

Loose terminals I could see. Not the case here.

And I get all that, but I don't see how you go from full to zero to full again with anything but a loose terminal. But I plan to do all that anyway. I appreciate your efforts in attempting to diagnose such a tricky one. Thanks!

 

[brillo_76]

Also check the wires near the terminals themselves.. As old as these are you can have oxidation in the wires near the terminals and its barely making. Many cases of this has occurred in 3rd gen over the years.. You feel extra heat or its bulging around under the insulation.

Mostly that is in the starter wires though or the main wire that feeds the fuse box.. Those have been known to oxidize at the terminal too.. The alt charging wire is more rare and wouldn't be causing the symptom of all power loss. Then working again. Its likely the wire going from the battery to the fuse box main if not terminals themselves.

You find it just going to take some investigation and maybe a meter with continuity or resistance check on some wires.

The battery acid mostly gets the wires right at the eyelets or crimps from my experiences in the past. Its crazy but is known to occur in older rigs.

 

[pluton]

There is also the possibility, however small, of internal damage within the battery. Has this battery been subjected to big hits, shaking on washboard roads, etc? If you could rig a volt meter at the terminals, run the leads into the cab, and have it on before, during, and after the starting attempts, would it show the on/off of the power?

 

[RogueWaive]

There is also the possibility, however small, of internal damage within the battery. Has this battery been subjected to big hits, shaking on washboard roads, etc? If you could rig a volt meter at the terminals, run the leads into the cab, and have it on before, during, and after the starting attempts, would it show the on/off of the power?

No jarring.

And remember it wasn't the starter. There was zero power upon entering the cab. No dome light. No power door locks. No instrument panel lights or noise upon key insertion and turning. Nothing.

Several minutes later?... full power.