90 T4r SR5 4x4 w/ auto trans.
Engine/Trans rebuilt 2 years ago
1 month ago replaced the battery

Over the past few weeks, on 3 or 4 occasions no power, as if the battery had been removed. On the last 2 incidents found if I remove and then connect the positive cable the power comes back on, it is as if there's, for lack of a better term, a circuit breaker or fuse that resets until the next episode. Curious if there's a circuit breaker or fuse in the panel to the rear of the battery that is the culprit?

Any thoughts, and/or suggestions appreciated!!

 

Dave, pls put us AT YOUR VEHICLE.
A problem well-described is almost solved.
What engine?
Exactly where do you lose power? Lights? Cranking circuit? Hazards and horn? Radio? Turn signals? Back-up lights?
Our senses are the most important diagnostic tools. What do you see, hear, smell, feel when you have the problem that are different from what you see, hear, smell, feel when you don't have the problem?
Next to our senses is the multi-meter? Got one?

If you describe your problem well we could help even from here

 

It is a V6. As I mentioned there is 'no power' it is as if the battery was removed, none of the electrical circuits or components came on. Prior to this, I was having problems with the starter, which had been replaced, where the starter would not engage, again this would happen on occasion. I thought the problem was solved when the negative feed to the starter appeared loose and I was able to reach the connector and move it further onto the post. During these episodes with the starter, on 2-3 occasions, I relied on jump-starts to get me home and it was after this when the 'no power' problem surfaced. At first I thought possibly the auto shifter was the problem since it does not, has not lock in the park position for some time; however, with power, all seems well. With the last couple of incidents, I removed then connected the positive cable and all is well, all the instruments, horn, wipers, lights, engine, worked until the next 'no power' episode. I thought perhaps whether it be a relay, fuse, or something similar close to the battery would trips and prevents any power to the vehicle and when I remove and reattach the positive cable it resets this relay/breaker until the next episode? Apologize, I am not knowledgeable when it comes to electrical circuits and terminology?

I thank you for the input!

 

Cool. Good you came here for your second-gen T4R. More owners are active on this forum than on T4R.

Shifter lever would not affect anything other than cranking. Maybe power locks, windows, etc on LATER models.

Make sure your connections are bare, shiny metal tightly against bare, shiny metal.
Check connection from battery positive to fuse block. The wire between battery positive ad fuse block may be THE FUSIBLE LINK (mentioned in T4Rdot_ORG).
THICK Battery cable from batt positive to screw-terminal on starter SOLENOID.
Ground wire from batt negative to fender ground.
THICK wire from batt negative to engine block ground.
Make sure your connections are bare, shiny metal tightly against bare, shiny metal.

Get a multi-meter if you want to learn how to work on electrical system of your truck. We can help but you have to have your tools, AND you need to show us what you are working on by posting pictures if needed. Some of us do not see words very well. A picture paints a thousand words.

 

Mine is not a V6. It's a 22RE. It did what you are describing, and it was the connection between the under hood fuse block and battery. Crimped on a new lug, and that fixed the problem.

 

Posting a few photos of the engine compartment, I can see where the positive cable goes into what I believe snippets refers to as the fuse block; if so, not sure how to gain access to the other end to check for security. I checked connections at the distributor and coil and wires do not appear frayed or damaged. I did purchase a new distributor cap and intend replacing once the other issues get resolved. I ran a separate wire from the negative battery to the fender ground connection. Not clear how removing then connecting the positive cable seems to reset the power, curious if there's an item in either of the fuse block that trips and resets when power is reconnected. I do have a multi-meter and limited experience with earlier model trucks but the circuitry on the pre 70's vehicles is as basic as it gets and when I look under the hood of the 4 Runner I do not have a clue. I want to thank you both for your comments and suggestions!

 

Sounds to me like either a poor/loose ground connection to the battery, or a poor connection from the positive cable to the fuse block. Either way, as the vehicle sits, the connection corrodes and opens, so no power. Then when you remove the positive battery cable, you incidentally wiggle the other connections enough so they work again - for a while.

As @Rad4runner says, make sure both terminals on your battery connect to the cables tightly, with bare shiny metal against bare shiny metal. Also check where the battery cable connects to the chassis/engine ground. When the problem recurs, turn on your headlights and then wiggle all of the cables near the battery until you see the lights flicker on. That will be where you need to look further.

90% of global vehicle electrical problems are either a bad battery or poor connections at the battery terminals. That's always where I start looking.

 

You sound like you're very close; you should be able to find the suspect wire (and maybe the end of the wire) with just a wiggle test. Turn on the radio, and move the battery cables until you hear it cut out.

 

I took it to the shop to have a starter installed and they were unable to duplicate the problem what they did do was either replace or repair the battery connections. I have been testing the vehicle several times today and so far no episodes most likely will happen at the most inopportune time and when it does I will try the wiggle test. I also paid to have a tune-up and looking at the receipt today noticed they did not change the plugs, ignition wires, or distributor cap? I will be close to a dealership in the next few days and pick those items up.

I am really grateful to U'al for the comments and suggestions!

 

Dave,
Many of us are on this forum because we do not trust shops or stealerships.

Why did you have the starter replaced?
Don't wait for the problem to occur again when you want it least. Do the simple and FREE checks we have suggested beforehand.

 

The starter solenoid would not engage, turn the key and only get a click sound, progressively got worse requiring a tow? I have spoken w/ parts person at the Toyota dealership and it would take 7-10 days to order a replacement, which I have not done until the current issue is resolved.

 

Took pets to vet, leaving parking lot 'no power took snippits suggestion in using the ' wiggle' approach and immediately found the source of my problem. Best repair option would be to replace the wire running from the positive battery post to the fuse block but decided since I had no clue what would be involved in removing the fuse block I replaced the connector and so far appears to have solved my problem? I thank U's all for the comments and suggestions.

 

Yes that's the repair I was talking about. Same thing I had to do on mine back two years ago. Glad you got it fixed!

 

Yup,
"Toyota components are bullet-proof. Issues often arise from poor wiring, assembly and/or maintenance. Suspect those first."

 

Yes, the problem was due to poor wiring, incline to believe fortunate the vehicle had set in the hot sun for over an hour, appears the heat-shrink was soft and mushy and it did not take much of a 'wiggle' for the wire to separate from the connector.

Thank U's all for U'r comments, very helpful; hopefully may have contributed to the starer issue, time will tell!.

 

Just to state the obvious, the heat-shrink is just insulation and has nothing to do with the electrical connection or the mechanical integrity of the joint. You should be able to pull "pretty hard" on that wire with no movement. The heat shrink is just the "icing on the cake."

 

I did not notice any solder on either the wire or connector; it appears, whether it be me or shop, the connection was not soldered rather the wire was inserted into the heat shrink connector and heat was applied to attach the 2 and perhaps basking in the sun for over an hour weakened the integrity of the connection?

 

It should have been a crimped connection, not soldered. If the proper crimping tool was not used, it's likely the crimp force was inadequate to seal the connection gas-tight and corrosion got in eventually causing failure.

 

That's not how it works. Given your explanation you should read up in electrical connectors.

Here is a randomly selected link http://www.instructables.com/id/How-...Crimped-Joint/

If these aren't done correctly, compressed to a very specific ratio with the proper terminal size for the wire size, you wind up with a compromised wire and connection. Which is what you had. It's also worth noting the extended sheath on the terminal functions as strain relief to keep the terminal from cutting into and breaking the wire strands.

 

Yes, followed by no...

The barrel (the part the wire is inserted into) is open at the opposite end. Unless you are using very specific terminal ends (like telephony connectors) meant for harsh exposures, they aren't intended to be impermeable to gas/liquid.

The heat shrinking thermo-plastic is for strain relief, you can tell this style of terminal by the length of the plastic beyond the barrel. If you don't have this "large" length the plastic is only there for insulation, this insulation only type is not intended for use in situations where the wire is subject to vibration.

The rubber in the Weather-pak™ connectors used elsewhere in the engine bay serve the same purpose (yes they also keep some of the water out)