DanStew

1989 4runner 22re
after work yesterday i jump in the 4runner to go home
put key in and not cranky. no lights. no nothin.
Get pal to jump me. Before he jumps me, i have 12.75 volts on battery.
We put jumper cables on and it jumps just fine, crnaekd right up.
I let it idle to warm up and notice my dash clock flickering. never did that before.
I put headlgihts on and the engine almost dies.
So i drive home with no headlights.
When driving I noticed when i had RPMs over 2200 the "charge" light came on, and if i had the motor in to high of gear with too little RPMs, the "charge" light came on.
I get home. and before i pull into the garage i see how far i can get the engine to pull down when i turn on electrical items. I put on headlights and the engine lugs down, then i put heater on full blast and it died.
I push it into the garage. Check battery voltage and it is 12.95. And with the key in ignition it still acted like it was dead, no lights or anything.
I get the wrenches out and pull the alternator.
Get alternator checked and it passed. [scratches head]

So today i take battery to get checked.
IT passed fine (only a year old)
So now I am really scratching my head.

Battery cables are just fine, no corrosion, grounds are good.
I can't imagine it being fuses since i can get jump started with another vehicle. Same with ignition switch, it works fine with another vehicle hooked up.

Somebody mentioned a fusable link, did Toyota use them in 89?

Anything else in line that i should check?

mt_goat

Probably, my 93 has one.

leebee

which grounds did you check? alt to block or just neg on battery? might want to look into ' big three upgrade'.

dale, if it were the f/l, wouldnt that keep it from starting from a boost? im not sure, thats why im asking. doesnt that work like most fuses, if its 'broken' no current passe through, ergo, no start?

lee

mt_goat

I'm not sure, I was just answering his question "did Toyota use them?"

DanStew

I am gonig to recheck the ground cable. i checked it at the battery, not further. Going over it all, that really looks like the biggest factor, since it will start with a seperate vehicles ground. Guess it just had enough connection to let the truck run. And when i added the headlights and heater it was too much for it.

leebee

hey dale! no worries, i was asking for myself and hoping i would be better prepared should my rig give me grief in the near future.

dan, let us know what you discover and your fix.

lee

abecedarian

couple things to check:
DC voltage at rest (key off) should be 12v or higher
DC voltage with engine running should be at least 13.5 volts, 14.0-14.5 at most.

also, check AC voltage at the battery and post the reading.

mt_goat

That's interesting

DanStew

Well it definately was the ground circuit. I put the truck back together and checked the ground wore. it looked fine but i twisted it and you can tell it was a bit crunchy inside. So after moving it for a bit, i went in the truck and the dome light was on... good sign. I put the keys in and cranked her up.Ran just fine, except that the charge light and brake light was on, i wiggled the ground cables again and they went out. So iut is up and running so far, i will replace the straps hopefully this weekend.

Thanks Guys!!

leebee

research 'the big three', might as well take care of that while you are doing the ground repair and have things apart.

lee

abecedarian

good deal.

/me hides

abecedarian

This is a 'side quote' and commentary:
Significant AC voltage at the battery would imply 1 or more failed diodes in the alternator. The alternator would still charge to "X" voltage due to the nature of the regulator circuitry, but since at least one phase has been compromised, the negative voltage (from the failing winding) would discharge the battery as much as it charged it. So, one could end up with a battery at 12.5V (for instance) but it would only be a surface-plate charge and that charge would be quickly depleated when a significant load was placed on the system.

mt_goat

That's interesting

DanStew

Well i swapped out the grounds. Boy is that some small gauge wire