khany2002

I have a bone stock '86 4Runner with a 22RE. It's got about 85,000 miles on the vehicle.

In the past two weeks, I've noticed some weird electrical issues leading up to complete power failure in the vehicle while trying to start it in a parking lot today.

Background:

About two weeks ago, right after I started the vehicle and backed out of the driveway, when applying the brakes, I noticed what seemed like all the red warning gauges in the cluster light up briefly (less than a second), then go out. It never happened again. From my research, I know that if the charge and brake lights stay on while the vehicle is running, that means the alternator is cooked.

About a week ago, I was in the process of taking off the faceplate from the radio (flip-face Pioneer deck) with the engine off and the key in the accessory position. While the face was flipping open midway, the unit shut off, then restarted a second later -- whenever I would try to flip the face forward to remove the faceplate, power would seem to be cut to the radio. After about 5 minutes of power cutting to the radio ONLY when I tried flipping the face forward, the glitch disappeared, I removed the faceplate, and thought nothing more of it, and it never happened again. This radio was installed over a year ago, and I did a pretty good job of the wiring, so I'm not too concerned about wiring faults, but let me know. I assumed it was my year-old headunit breaking on me, rather than the vehicle. I know the radio has a circuit built into it that shuts it off if power falls below 10 or so volts in the vehicle.

Today, I drove the truck to the store, was gone for about 5 - 10 mins (no accessories were left on), tried starting the vehicle, and NOTHING happened (no clicking -- nothing... full power failure). When turned to START, all the red warning lights went out, and when I turned the key back to 'ON', all the red warning gauges were now very dimly lit, the green Toyota clock now read 1:00 (it had reset itself), my headunit tried to turn on automatically, and shut itself off a few times. My headunit has a cheap 'voltage readout' in one of its settings, and I got the headunit turned to it -- it read 9.82 volts. If I turned the key back to OFF, then cycled back to ON, all the red warning gauges were back at their normal brightness, and the voltage readout on my headunit read 11.8 - 12.1 volts. I checked all the underhood fuses, and all the ones on the driverside kickpanel. and everything seemed okay. I tried starting the vehicle again -- no start and power failure again. I immediately tried starting (less than 5 seconds between the last start), and the vehicle started normally as though nothing had ever happened. The voltage readout on the headunit was at 13.2 volts at idle, and at around 900 RPM, read 14.7 volts.

I would say the battery was toast, based on the 9.82 volt reading, but it was fine. I came home, let the vehicle sit for a bit, and checked the battery with a real voltmeter. It read 12.1 with the vehicle off, and 14.6 with the vehicle running, regardless of RPM. That tells me the alternator is working. I would suspect the starter, but, judging by my radio turning itself off with just a little load placed on it, without trying to start the motor, I suspect something else is at play.

I'm kind of worried to take the truck out now, as I don't want it leaving me stranded -- if you guys have any idea what this could be, I'd really appreciate your input -- I'm pretty clueless when it comes to electrical issues!

Thanks,
khany2002

Jay351

Did you clean the battery posts and cables?

Team420

oh yeah....you gotta clean those posts!! My rig does the same thing every now and then...I also leave the terminals loose, for quick swaps.
Pull the terminals off, clean the posts...and if it were me...I'd just spend the $10 max, on new terminals, and be good for years. Either way....make sure they are tight when you put' em back together.

khany2002

There is no corrosion buildup I could see around the terminals, but, I'll take them off, clean them, and report back -- I had cleaned all the terminals just a few months ago, but you never know! If the battery has failed, it's got a lifetime warranty, so that's free if it is toast -- it's only two years old though, so I can't see that being the cause.

Thanks a lot!

Team420

I doubt it, when a battery goes bad...they dont just suddenly die...no power...and then come back later, they go slowly...ie your fine, then one day, ur rig wont start...jump it...then get a week or two, then dead again...jump it, get a couple days before it wont start..etc etc Also, it would still have some power, just not enough to roll the motor over. What u described, sounds like a connection issue....like I said...take the terminals off and clean them good, or if it were me...toss them and get new ones, then clean the posts, and tighten everything up good. I bet my left nut that fixes your issue...lol

abecedarian

my experience (not just on toyota's mind you) is that weird problems like things turning off and on randomly are 90% grounding issues, and the other 10% are faulty crimps on wires, corrosion on connections, etc.

so, having checked the voltage at the battery... wise choice considering the radio reported <10 volts and finding >12 with the engine off and >14 with it running... tells you a couple of things:
>12v/off implies the battery has decent storage capability left in it, no serious short in the wiring or other draw.
>14v/running implies the connections between the battery, alternator, engine and chassis are all good, alternator output is more than enough to accomodate the electrical load on the system at that time.

... off to the next things:
loose, corroded or otherwise bad grounds in the harness(es) under the dashboard
corroded or otherwise bad connections to the fuses themselves ... or ...
corroded or otherwise bad connections to the fuse blocks (yes, there are two)

grab your ohm meter and check resistance in the power leads all the way to the battery... and do the same for your grounds.

I would probably bet the problem lies in the power lead(s) between the fuse block under the hood and the one inside the truck since the intermmittent issues is affecting both your radio AND starting circuits.

khany2002

Hey Everyone,

Thanks for all your help!

I went and checked all the underhood fuses, as I figured water could've sprayed in there at some point (although doubtful -- the truck has never been taken off-road / into water its entire life).

I removed the terminals from the battery posts, and there was a little bit of buildup around the terminal posts -- not enough that I would've thought could make the vehicle not start, but, I cleaned the posts and terminals with sandpaper, then coated everything with a thin layer of grease.

So far, I haven't been left stranded, so, I guess whatever I did must be working -- if that's the case, I feel like the biggest idiot -- I suspected my problem was a lot more serious - more along the lines of what abecedarian was suggesting -- a relay under the dash being fried -- it's a little premature to think I'm out of the woods yet, but, I'm hoping!

Here is a picture of the little bastard in question:




Thanks for all your help guys, I really appreciate it!

abecedarian

seems like your problem is handled. congrats!

only thing I will suggest now is that most grease is an insulator. maybe something more like anti-sieze compound, kopperkote or noalox would be a better alternative. they all repel water and are electrically conductive, and the last two are meant for joining two electrical conductors together.

and I never said you had a fried relay

...that is all.

desert-rat660

i u have the extra cash id say get an optima battery, i dont have the corrosion problems with the gel cell, and the damn thing has been through 3 different vehicles and it still works like new