Complete power failure while driving in my new Land Cruiser 100 (2 Viewers)

[CruiserActual]

I recently purchased a 1999 Land Cruiser 100 series with 135,000 miles on it. The truck came from an estate, and has only been driven 10,000 miles in the past 10 years. Over all the truck has been well taken care of, always garage kept and no rust or other issues that I am aware of. I am in the process of baselining it and doing some preventative maintenance and replacing parts which are known to fail. Previous owner maintenance includes:

2014 (118,000 miles) - Thermostat and gasket replaced
2015 (122,000 miles) - Master fuse box replaced
2019 (130,000 miles) - Valve cover gaskets replaced
2021 (131,000 miles) - New battery

While driving it to work yesterday, I started having some issues where the radio was making weird noises while driving. Specifically, there was a high-pitched noise coming from it which increased and decreased with my RPM's. On my way back from work the radio intermittently started losing power for a second and then powering back on every few minutes, and I noticed I was also losing power to my cigarette lighter ports as well. After about 10 minutes sitting in traffic, it got worse and was happening every few seconds, which was followed by complete loss of power to the vehicle. No power steering, brake pressure, electronics, etc. I was able to come to a stop, put it in park, and it started back up right away and the power issues did not happen again on the 20-mile drive home. I did not have any check engine lights or codes from this and the only code stored when I plugged in my code reader was P0125 for Insufficient Coolant Temperature for Closed Loop Fuel, which I have had since I purchased the vehicle 1 month ago. Both times when I experienced the issue, I was going 25mph or less, and I did not experience issues at higher speeds. My initial thoughts are it could be related to the work I have done this week, which includes cleaning the MAF sensor and trying to unsuccessfully program new remotes to unlock the vehicle.

- MAF Sensor:
I see several other posts where people have similar issues involving faulty MAF sensors, and since I recently cleaned it this would be my first guess. I unplugged the sensor, removed the screws, sprayed the MAF sensor with CRC MAF cleaner, let it dry for about 10 minutes, and then put it back in. I was careful not to touch the wires, and since returning home I pulled it back out to inspect it, and reassembled it to see if I possibly assembled it wrong the first time. I don’t see any obvious damage to the sensor or wiring harness. I also forgot to reset the ECU after cleaning, so I disconnected the negative terminal on the battery and have now reset it. The sensor appears to be functioning correctly, and my obd scanner shows .17 grams per second when off, 6 grams per second while idling (800 RMP) and when I increase the RPMs to 1600 it goes up to about 10 grams per second.

- Programing new remotes:
My land cruiser came with 2 keys, one which unlocks the doors and starts the vehicle, but does not seem to be a master key since the key/anti-theft light next to the AC controls does not disappear when I start the car. The second key unlocks the doors and glove box, and the car will turn over but does not start the car which makes me think it is not registered.
I unsuccessfully tried to pair my new remotes to the vehicle and followed several YouTube videos, and I am wondering if I potentially messed something up and the anti-theft immobilizer potentially what killed the power. This seems less likely, since the vehicle started right back up and I haven’t had any issues starting the truck at all.


Other possible causes:

- Loose battery connections: When diagnosing the issue, I noticed that both the positive and negative terminals were loose and I could remove them by hand. I have tightened them down now. There was no corrosion on the battery, and it is 2 years old. It could also potentially be an issue with wiring or ground. I don’t see any obvious wires that are loose or cut.

- Fuel pump, fuel filter: The one time this has happened to me was when I had about 1/4th of a tank of gas. I have seen several other threads with similar issues where the fuel pump/filter needed to be replaced. I am not sure if this potential issue would cause intermittent radio/cigarette power issues prior to full power loss. I have a new OEM fuel filter that I was going to replace, and I could replace the fuel pump as well since I am baselining the truck anyways.

- Bad Fuse's:
Similar posts with issues relating to fuse issues which could potentially cause similar issues. As noted above, the master fuse box was replaced in 2015 (15,000 miles ago). Could be an issue with the EFI main relay fuse? I have heard some people also suggest getting a bypass from Medtro as well.

- Coil packs: I have also read several posts with similar issues relating to bad coil packs, but it seems like this issue typically includes throwing codes which my vehicle is not.

- APPS/TPS: Same as the coil packs, ive seen multiple posts with similar issues relating to APPS/TPS but they typically seem to throw codes if this is the cause.


Any advice as to which issues I could potentially rule out based on my situation would be great, and I would love to know where you would suggest starting my trouble shooting. I am going to go to an auto parts store later to have my battery and alternator tested to rule out any issues, and will likely drive around and try to replicate the problem.

 

[CruiserActual]

*UPDATE: Autozone mentioned that my cold cranking amps were lower than they should be and my voltage was at 13.6. They also said that the alternator has an open diode and likely needs to be replaced. Would this likely be the cause of my car dying while driving? My understanding is that if the alternator wasnt working, then the battery would slowly drain until the battery was too low and that could cause the car to die while driving which makes sense, but what doesnt make sense to me is that I was able to start the car back up just fine, and havent had any issues with a dead battery.

 

[213374U]

Yup, alternator needs replaced. The battery is only there to start your vehicle, the alternator provides all the juice while it's running. If the alternator dies it will run on battery until the battery is drained. You should see the red battery light on your dash illuminated.

EDIT.... missed the end of your last post. If battery isn't dead.....

 

[Thingfisher]

I would second alternator as a culprit. A very similar thing happened to me (newish battery and electrical gremlins).

 

[toyuda]

I would be curious to see if tightening down the loose battery terminals didn’t rectify the problem.

 

[nissanh]

"Loose battery connections: When diagnosing the issue, I noticed that both the positive and negative terminals were loose and I could remove them by hand"

This will kill the diodes in the alternator.

 

[CruiserActual]

Alright it seems like everyone agrees that the alternator is likely the issue and probably needs to be replaced one way or the other. I'll be taking it in for a timing belt/water pump job and will have the mechanic take a look and replace it if he agrees. Hopefully this will be the one and only time that it dies while driving. Thank you to all for the input!

 

[shtbrwn86]

Another thing to look at when doing the alternator is the power steering pump. On mine (according to dealer records) the PS pump was leaking onto the alternator which caused it to fail. If you end up replacing the alternator I would just the PS pump a good once over to make sure it's also not leaking.

 

[Patassa]

*UPDATE: Autozone mentioned that my cold cranking amps were lower than they should be and my voltage was at 13.6. They also said that the alternator has an open diode and likely needs to be replaced. Would this likely be the cause of my car dying while driving? My understanding is that if the alternator wasnt working, then the battery would slowly drain until the battery was too low and that could cause the car to die while driving which makes sense, but what doesnt make sense to me is that I was able to start the car back up just fine, and havent had any issues with a dead battery.

Yes, replace alternator with new OEM. Make sure you aren't dripping power steering fluid on it via a leak running down the hoses from the PS fluid container or the pump itself, if so, fix that before it kills your new alternator too.

Edit: Just saw the post above mine. As you can see, some of us have learned this the hard way. PS fluid will kill a perfectly good alternator and leave you stranded, it's no fun.

 

[2001LC]

*UPDATE: Autozone mentioned that my cold cranking amps were lower than they should be and my voltage was at 13.6. They also said that the alternator has an open diode and likely needs to be replaced. Would this likely be the cause of my car dying while driving? My understanding is that if the alternator wasnt working, then the battery would slowly drain until the battery was too low and that could cause the car to die while driving which makes sense, but what doesnt make sense to me is that I was able to start the car back up just fine, and havent had any issues with a dead battery.

Loose battery connection is number on reason, for total lose of power while driving. Has it died since you cleaned post/clamps and sung clamps the down?

Not so fast on alternator R&R.
"CCA low", 13.4 volts? If alternator bad either under or overcharging. You not see 13.4 volt on battery engine OFF unless just charge with a charger. You'd not see 13.4volts or on post or clamps engine running, while testing alternator.

An undercharged battery, then would have drop voltage to low for engine to run. It would not have started back up, without long jump/charge.
If overcharging. It would have burnt-up the battery, and to low for engine to run. Again would not start back up.

A battery sitting not being fully charged daily (few days) over time sulfates. We see weak batteries often, that go bad. If not a daily driver and not kept on trickle charger. They then, do not hold a full charge. Resulting in no start no crank or weak crank.

P0125 is most often. The cooling system is low on coolant. So other after a coolant service (flush, timing belt, thermostat, anything coolant drain for) air is not bleed, underfilling. If to low, it's below water temp sensor. It's then a false P0125, since engine actually very hot even over heating.

Immobilizer light on key in. Is a separate issue. Immobilizer only cuts power to fuel pump, not all power.
On solid, blinking a code, on a moment after key then off or what?.

 

[CruiserActual]

UPDATE: I drove it for another 30 miles yesterday. According to OBD fusion, battery voltage was around 13.8-14.2V when driving at higher speeds consistently, but quickly drops to low 13's when driving slower. I went by a different auto parts store to have them check it as well and they also confirmed that the alternator is having issues with the diode and voltage regulator. I'll have my mechanic replace the alternator with OEM and report back when I find out if there continue to be issues or not. With alternators, is it typically fairly cut and dry where the alternator is either good or completely bad and not working, or do they sometimes work intermittently when they are going bad? This definitely seems like the most likely cause of my issues one way or the other.

As far as the power steering pump leaking on the alternator, I don't see any obvious signs of fluid leaks around the alternator. Would you guys expect the leak to be pretty obvious and leaking under the car, or just a small amount dripping onto the alternator?

P0125 code: I cleared it out with my scanner and will be replacing the radiator hoses and heater T's so I will also do a coolant flush and fill. If the code comes back I will investigate further.

 

[CruiserActual]

In addition, does anyone have recommendations on an alternator? I'd like to stick with OEM, but it sounds like they don't make new OEM alternators any more, just Toyota remanufactured ones. Would you guys suggest a Toyota remanufactured one or new/remanufactured Denso?

 

[Ayune]

27060-50260 is the new OEM alternator you need. Perfect replacement for my ‘98. Reman has “-84” at the end so find the part without that suffix.

EDIT: Yikes, looks like reman is the only available option now. I wouldn’t worry about quality if purchased from a dealer.

 

[CruiserActual]

I ordered part number 27060-50260-84 for the replacement. Sticking with OEM everything and from what I read, people have had good luck with the OEM remanufactured alternators from Toyota

 

[2001LC]

All Toyota/Lexus alternators, are -84 (remanufactured). I would not use anything but Toyota/Lexus branded.

Voltage regulator. Regulating Voltage: 13.2-14.8 Volts at 2k RPM. 30 AMP or more.
Voltage at post of battery 12.5-12.9Volts. "Battery, less than 20 minutes after driving, surface charge removed (headlights on than off, for 60 seconds to remove)."

As I noted above: P0125 code is most often associated with low coolant level.

Whereas I suppose you could have a funky alternator, being intermittent. I've only seen, either good or bad. Bad is either over-charging, which cooks batteries, or undercharging. Undercharge "may" result in sulfating a (weak) battery.

When we test charging circuit. We a instructed to do so, tapping into wiring at alternator. But I've found, just checking on clamps at battery, has be reliable enough. Provide wiring attach properly to alternator, and routing to battery all good. There is a fusible link, hanging off positive battery clamp. I've seen these in very bad condition. They get that way, due to battery acid corrosion. That white powdery looking stuff on batteries. Which is acid. Acid we wash off with baking soda/water to neutralize acid.

I'm thinking you've a poorly or improperly maintained engine compartment. Possible, you already have a replacement alternator. With age and miles, many hands touch these rigs. Many hands, that aren't experts on 100 series or meticulous in repairs. I call them "gorilla's". Which most every, shops has them.

If you'd like to stop by, I'll took a look. PM me with contact info!

 

[213374U]

UPDATE: I drove it for another 30 miles yesterday. According to OBD fusion, battery voltage was around 13.8-14.2V when driving at higher speeds consistently, but quickly drops to low 13's when driving slower.

This is exactly what happened to mine when it was on the way out. At the end, in stop and go traffic I'd have to shift into N then give it revs to keep it from dying. New OEM alternator will fix you right up.

 

[CruiserActual]

*Final update: It was the alternator as suggested by the two auto stores I had test it and members here. One said it was an open diode, the other said open diode and failing voltage regulator. I replaced the alternator with the OEM remanufactured one from Toyota (P/N: 27060-50260-84) and have driven it 2,000 miles with no issues.