Alternator over charging?

L

LIL QIK

Registered User
I'm a little confused........I bought an alternator that wasn't charging at all........then I bought one that seems to be over charging. Can anyone tell me if there is anything on these cars that's suppose to regulate the voltage to the battery other than the voltage regulator. And is the voltage regulator internal on the alternator or does the SC have an external regulator. Now any time my rpm's are over say........1200........My lights get real bright and when I stop.........I notice that the battery is warm and has acid on the top of it, along with the tops being popped up a little on the battery.

Any suggestions?

Thanks.....Dave :D
 
Well I take it from your statment that you do not have a multi meter for measuring voltage. If you do then it should be between 14.0 and 14.4V when the engine is running. If the battery is hot and bubbling then chances are that you are overcharging the battery. Get it checked before you uin the battery. And don't try to disconnect the battery with the engine running. You could fry the computer(s), an alternator can put out as high as 80V if the regulator goes bad. With the battery in place it will typically limit the voltage to less than 20V.

I can't think of a car in the last 30 years that hasn't had an internal regulator. It's internal to the alternator.

Jeff
 
Also, if the battery is dead, don't use the alternator to charge it. Bring it up to proper charge with a regular battery charger before using it in the car.

The work involved in bringing a battery up to full charge will kill an SC alternator. It's not designed for that duty cycle.
 
Ok........guys..........I got to the O'riely's last night and sure enough the battery was practically boiling. I let everything cool down for a little and then we went back out to test it. It seems the alternator is pumping 17.96 volts to the battery. So I'm going to have them order me a new alternator today...........just incase the voltage regulator is gone........or freaking out. I also went ahead and bought a new battery..........turns out the one that was in the car was quite a bit smaller than the one that's actually for the car.

But now I'm worried about my computer as well. It seems my EEC fuse was totally melted. I noticed that before I left last night when I was trying to get my fans to come on. I'm slowly but surely getting burned out on this car.

Has anyone had any experience with the computer being the reason the fan won't come on? Everything is new.......the fan motor.......the IRCM........what else is there that controls the fans........

Anyway.......by the time I got everything back together last night.......they had already closed up. So I wasn't able to check and see if the battery change had anything to do with the over charging.......I know that doesn't make any sense..........but I was hoping.

I don't suppose the computer monitors alternator output does it.........yea.......I know..........I'm reaching..........lol
 
That's pretty much what I was figuring........this is my second alternator in like a week. The first one didn't charge..........the second one over charges..........

Maybe 3 times a charge?..........lol

Yeah yeah........I know........that was corny..... :D
 
It seems these days that no one replaces the diode trio and the voltage regulator. About all that gets replaced is the brushes, bearings and what ever part that failed. Whatever you do stay away from Autozone. I had a starter that I had to replace 3 starters in one month on one car.

Jeff
 
interesting that you should mention eec's and fans i took out my eec the other day to clean the pins and forget to disconnect my battery OOOPS oh well no harm done this time and when the computer ws out teh fans turned on wierdest thing
 
J57ltr said:
It seems these days that no one replaces the diode trio and the voltage regulator. About all that gets replaced is the brushes, bearings and what ever part that failed. Whatever you do stay away from Autozone. I had a starter that I had to replace 3 starters in one month on one car.

Jeff
Click to expand...
Took 3 autozone alternators for me to get a good one. All had regulator failures where, after heating the engine up, the output would drop off at engine rpm over 1200. But let it cool off and it would work fine.. :mad: :mad: So you spend 1hr removing the thing, take it in and it test out OK on the lame bench tester, so they, of course, won't do anything for you and think of you as some sort of boob that doesn't know what you're talking about. Quite aggraviting as when the battery eventually drains to where the car won't run, you're stranded.

Unforunately, when you need an alt, you don't have a lot of choices. Its not too hard to rebuild yourself, but with the price of parts and everything, its still cheaper to buy a rebuilt one.

Anytime you have a charging problem, Buy/Borrow: a voltmeter , battery electrolyte tester, and a trickle charger. If you don't have this stuff, you'll always be guessing ($$) about the problem and could end up replacing some expensive things more than once. A voltmeter, is the best diagnostic equipment you can have and the only way you can know whats going on. You will need it to prove to the Autozone clerk what the problem is so that they'll honor the warranty.

And prepare yourself for aggravation; this won't be fun. Oh, and 1 last thing, to be on the safe side: always recharge a drained/dead battery with the charger, not the alternator. I can't explain completely why that is, but on my 3rd replacement alt, I was very anal about that step, and test the batt before running the engine, and that alt has been good for a few years now. I was not quite as exactingly careful with the other 2. I would charge the batt to about 50-75%, so who knows. :confused:
 
Yea.........I'm lucky enough to not have to deal with too much aggrivation........every one in my O'reily's knows that I know more about cars than they do. I'm always in there and spend so much money that I probably pay for have their salaries.

Problem is.......is this is my first ford. I know absolutely nothing about fords.....especially in the electronics area. That's why the fans are just kicking my a$$.

But yea........I picked up another digital voltmeter last night. If I have anytime when I get off today........I'm going to run some more test. I'm also going to try this KOEO test......or whatever that acronym is.........but I'll have to do a little more research on how to get that done. I'm trying to get everything done properly in this car instead of having everything custom like on my twin turbo 383 truck.

So I took the fan controller off the car that I was using and plan on getting those damn fans working........right after I try another alternator.......ooooh........what fun!


Ok..........couldn't find instructions in the search........anyone want to give me a quick run down on how to do this test?
 
Last edited:
Where in Houston are you? If you like I have a meter and a degree in Electronic Eengineering.

I am on the NW side.

Jeff
 
J57ltr said:
Where in Houston are you? If you like I have a meter and a degree in Electronic Eengineering.

I am on the NW side.

Jeff
Click to expand...
Hell yeah..........I'm sure if anything you know more about the SC than me.......well........and electronics too.........lol

Anyway........I'm over in Alvin actually........it's in between Pearland and Angleton incase your not familiar. Give me a buzz @ 832-452-5664 and we can talk about when might be a good time for you. I'll come out to you.
 
Just wanted to let you guys know where this was..........Well O'reily's has been giving my Altima batteries.......they must have not been worth a damn cause now the you can't get them. So now their getting me in a Motorcraft alternator.........but unfortunately it's only got a 90 day warranty on it. I think any problems after this.......I'll just have the place that built my starter for my twin turbo rebuild the alternator for me.

I was thinking about upping the amperage on it for the sound system I'll be putting in shortly. Anyway.......I'll be picking up the other alternator tonight.....so hopefully all will be good.
 
You must log in or register to reply here.
Back
Top