Froadin

Had a few bad alternators from Autozona. So I went and got a good alt from the best place in town. Had them put a 70 amp setup in the alt.
And the same price as the previous JUNK from Autozone.
Now, I cannot keep the voltage up AT ALL.
Funny thing, I pulled the main fusable link while it was running, and the car kept running,
BUT the voltage actually went UP to where it was supposed to be. Car cooled down, A/F started reading normal. Soon as I killed the car,
everything went dead, and would not power back up like normal.
Now, this was absolutely NOT happening a week or two ago. I specifically remember yanking the main fusable link while running and the car died like it was supposed to.
Now, are there any relays that could be stuck? Or what else could have happened/changed to cause this one?
My nice shop manual (year specific, not generic) got soaked and fell apart a month or two ago, so I don't have a wiring diagram to
save my life right now.
Anyone know this one?
Couple days later, after messing with a few things like putting in a larger fusable link. The alt was running at full voltage.
Actually it did this before I swapped the fusable link. So I took it for a drive. It ran just fine for a few miles, then as usual,
it started to run at low volts, the fuel pressure dropped, and the car started to run hot.
What on earth would cause this type of intermidiant problem? The wires I know about all seem and check out good. But is there any relays,
or some other thing that could be causing this fiasco?
Any help is appreciated right now.
Thanks

Pele

iTrader: (28)

Pulling the fusible disconnects you from the battery, but leaves you connected to the alternator. That's why your car kept running.

What are your mods like, specifically electrical modifications. (Extra gauges, hardcore stereo, ignition stuffs, fan.) That may be waht's keeping your voltage low and why your car died on the old 55 amp alternator.

Also, double check all your major connections on the battery, and grounds.

How old is your battery? Get it checked, might be borderline.

Froadin

Battery is almost new. A few months old. And had it tested. Does fine. Even had it tested while the voltage was low.
I have no mods electrical wise. A A/F gauge is the only extra thing I have. There isn't even a stereo in it.
All known wiring connections look fine. I cleaned them all up anyway, but still the same.
It will start to drop voltage just driving. But it usually does it when I turn on the lights or heater fan. It acts like the alt is only putting out 20 something amps (what the cheapies from Autozone did).
I even ran a jumper cable from the alt to the battery to make sure the power loss wasn't in that wire or connections. It still ran low volts.

Froadin

^

FJ

If the voltage was normal (~13.5) when you disconnected the battery by pulling the fusible link, it looks like the battery is the problem. How was it tested? The best way is to have it load tested in the car and they will be able to tell you if it is the alternator or the battery.

How did you clean the connections? You want to disconnect the battery terminals and clean them with light sandpaper. Also remove the two grounds on the ground cable at the strut tower and on the engine and clean them with sandpaper.

If something was drawing too much current the voltage should have stayed low when you disconnected the link, so you're looking at the grounds, battery or alternator.
You can do some more checks with a voltmeter, but the best bet is to clean the grounds and do a load test.

-John.

Froadin

Ok, to clarify, I have had the battery and the alternator load tested on the car.
I scuffed all connections I cleaned.
I even had the battery tested on the car while it was showing low voltage. (At that time it was the cheap alt from Autozone.)

I have very few things left to test. Even though the battery cables show fine, I am going to replace them anyway for peice of mind.

The kicker is that it ran FINE for a few miles of normal and hard driving. Then the voltage just dropped back to 12.3 ish.

FJ

Hmmm...the battery load tested o.k. while the voltage was low and yet the voltage came up when you disconnected it. That IS strange. With any luck your ground cable is corroded inside and your problem will be solved when you change it.

You'll let us know what you find?
Good luck.
-John.