badbob94

Help! New Alternator Battery Light on when Cold
Folks--thanks in advance for your expert advice.

I got a 98 with 295k. I just replace my battery with a DEKA 800 cca and this high output alternator from ACE

1998 Toyota 4Runner 3 4L 6CYLINDER 130AMPS Alternator 1 Year Warranty | eBay

Everything installed fine. Belt is tight. Battery connections tight. Cleaned the ground to the fender well, etc.

However, now when I start it in the morning the battery light is on. But after the engine warms and I SHUT IT OFF and restart the battery light goes off.

I've been documenting the battery voltage for several days:

Upon install:

Engine off=12.32
Idle=14.54
Load, 2k rpm=14.51v

Day 1

Engine off=12.55
Idle=14.31
Load, 2k rpm=14.27v

Day 2

Engine off=12.22
Idle=11.6 [14.62 after restart]
Load, 2k rmp=14.54
Turned off 12.55

It is obvious that the new alternator is not charging upon startup, but after it warms and I restart the engine it charges.

Battery is solid and each morning the engine cranks and starts right up.

But the damn battery light is on.

Any ideas! Should I return the ebay alternator from ACE?

badbob94

checked it again this morning

cold battery 12.8 v
idle 12.0 v
2k rpm 12.0v

check the 3 pins with engine off, key to ON


11.8v, 12.2v, 12.3v

Any ideas? My son suggests "resetting the computer" Not sure you can do that with a 4runner.

wyoming9

iTrader: (1)

Is the plug going into the alternator corroded perhaps pins bent ??

Something is causing a poor connection

Resetting the computer has nothing to do with the charging system but consume Electric !!

For Some reason the alternator is not getting excited till things warm up.

Is the problem inside or outside the alternator .

Now you no longer have any output ??

This issue only started after the Charging system upgrade??

Things were fine before ??

badbob94

We check those yesterday. Getting 12v to each pin, connects fine. I guess a pin on the alternator could be loose.

Perhaps, recall that the light goes on, and then after warming and restarting the light goes off and I get a full 14+ volts. I'm thinking either the computer is retricting the charging, or the alternator won't output when its cold.

Gotcha, thanks didn't know that.

Agree! Kinda like me as I get older.

That is what I'm trying to ascertain.

ONly when its cold. Once the engine warms and I turn it off and then restart does the light go off and I get a full 14v of charging.

Yes, new 130 amp alternator from ACE, and a new 800CCA Deka battery.

Well, I knew my alternator was going out. It was "whining" and only outputing in the 12v.

Thanks for all the questions and the help. Really appreciate it.

wyoming9

iTrader: (1)

Pull the alternator take it some place and have it tested!!

If it works then the problem is on the vehicle side.

I really thing the problem is in the plug area I have quite a few things check out good with the Meter and not work when plugged back together.

Is there any Arc marking on either side of the plug??

Perhaps a call to the alternator manufacture explaining just what it is doing.

Now you mean that when the engine gets up to operating temperature @ 192 degrees Is what you mean by warmed up ??

Not that you can run the engine a minute shut it off and have alternator output ??

badbob94

I just test it again. Same thing 12v cold. But after just a few minutes of running I tested it and it showed 14.6v and the light went off. WTH?

Agreed

If it does it again tomorrow I'll pull the ALT and have it tested and install the old one and see if the light turns off.

Right

Well, at first I just need to turn it off and back on and it was fine. Then on day 3 I need to drive it and bring the temp up to normal operating--half between the H and C on the dash. Pulled over, turned it off and on, and then the light went off.

Except for this morning . . . I need to run the engine until it reached normal operating temp before the light would go off--again, after turning off and then back on.

Check the ALT-S fuse and it is good.

Thanks Wyoming for all you help and suggestions

wyoming9

iTrader: (1)

Are you having any other strange electrical issues ??

Since you really had no problems .

Till your old alternator failed .

Putting that one back on will do nothing if it also does not charge.

Did you have the old one tested ?? what if it was doing the same thing not being excited .

I really wish I was close to look at this in person .

Quite a interesting problem!!

Sdsupra760

Get an new denso alt and dont look back