Battery light ?

ONLYTONY

ONLYTONY

Dedicated LVC Member
Joined
Jul 6, 2005
Messages
999
Reaction score
84
Location
East Hartford
On my 97 the batterylite stays on sometimes 3 min and yesterday for 15 min. I just took readings w/ohm meter. Sitting all night 10 degrees in the garage, bat 12.06. Started goes to 14.40. Light stayed on for 5 min. Voltage dropped to 13.75 with heater on high. Turned heater off and back up to14.4 and in 3 min started to come down as it should. Replaced slipping belt last week. Car runs normal except for idiot light on. Seems to stay on longer when it's out in the cold all day. Wifes DD so I have to find the cure. I plan on changing the alt and tensioner tonight. Thanks TONYyyy
 
They look good, but I'll check them tonight. Seems to stay on longer the colder it gets
 
12.06 is not super low for 10 degree weather IMO.

does anyone know specifically what triggers the battery light?
AC voltage from a bad rectifier plate?
low voltage? except that i drove 60 miles with a blown rectifier plate and failing voltage regulator, seeing sub 10 volts and never got a battery light.
is it pcm triggered?
or what?
 
Battery is 1 year old BOSCH ( stole it from the 98). This started a few weeks ago and it seemed like a slipping belt. Changed the belt and put in the good Bosch battery, removed the 2 year cheaper battery that came with the car. Cheap bat tests good and holds a charge on the shelf. My 95 and 98 were in the cold, both with newer Bosch batteries, and both drained down in 2 weeks, and neither wouldn't start. I now dis-connect the batteries and when I hook them up, both cars start right up. When the 97 is running, putting out 14.4 volts, the light shouldn't be on. I.m leaning towards a wire or alt.
 
My batt light did the same thing last year. Took the alt to az and had it tested three times and it failed on the third try. They gave me a new one on warranty.
They didn't want to give me a new one until it was proven bad so I had them keep testing until it failed. Sounds like your alt is doing the same thing.
 
In my experience with this car and a cougar sharing most parts, when the battery light goes on and off for some minutes at a time it's always meant the alternator is on its way out.

Also of note is that the alternator would test good IN the car but take it out and do a bench test with better equipment and it would fail.
 
I just ordered alt, tensioner and pulley from RA. Saved $33, time, and gas if I got them local. Local would have been re-built alt. At rock brand new. I think Chris is on the money with the rectifier plate. I'll get the old one re-built and have a spare.. Thanks for all the knowledge guys. TONYyyy
 
ONLYTONY said:
I just ordered alt, tensioner and pulley from RA. Saved $33, time, and gas if I got them local. Local would have been re-built alt. At rock brand new. I think Chris is on the money with the rectifier plate. I'll get the old one re-built and have a spare.. Thanks for all the knowledge guys. TONYyyy
Click to expand...

i break a lot of rectifier plates.. my alternator guy keeps them in stock for me.
 
I got a 100% new Gen 2 alternator off fleabay for $79 last year. Works great, still got 2 years on a full replacement warranty as well.
 
The battery light illuminates due to a current flow from the battery to the alternator. Putting it simply means the alternator is not putting out as much current as needed to balance the load from the battery. Since it comes on momentarily, the alternator is 'catching up' with the battery reserve depleted from starting the car. Normally the alternator 'balances' the load from the battery while it is charging and no current flows across the battery light circuit.

It is most likely either a diode or the regulator that is failing but it could be a bad harness connection as well.
 
I'm sure it's the alternator, and I ordered one from Rock Auto. E-mail this morning states my order will be shipped on the 15th. A WEEK!! I'll borrow one from the CE, it won't know, It's sleeping. I read that if the alt puts out 15.5 the idiot light will come on also.
 
ONLYTONY said:
I'm sure it's the alternator, and I ordered one from Rock Auto. E-mail this morning states my order will be shipped on the 15th. A WEEK!! I'll borrow one from the CE, it won't know, It's sleeping. I read that if the alt puts out 15.5 the idiot light will come on also.
Click to expand...

Can confirm, I had one alternator that the regulator went bad on and overcharged the battery causing it to explode. The light didn't come on till it was to late though, acid is fun to clean up.
 
I really prefer(ed) analog battery gauges in the dash. These idiot lights don't really tell you much.

How cool would it have been to have Check Engine and ABS codes actually show up on the message center and tell you in simple english what the problem is, along with the code?

Too easy!
 
Borrowed the alt from the CE and put it on last night. Did it while talking on the phone, and the guy I was talking to timed me from opening the hood to starting of the car..WOW 16 min, and I wasn't rushing. Some repairs just go nicely.
 
14.8v seems a little on the high side.
ford systems usually shoot for around 14-14.4v.
anything over 15 is definitely too high.
 
Upon startup I'll see 14.6.14.8v, after a little driving it'll go down to 14.2 and will finally rest @ 13.8-14v all nice n' hot.
 
Mine starts in the morning at 14.2-14.4 and after running around a little, it usually rests at 13.8-13.9 and when shut off, it shows 12.6-12.8 and I have been watching it since I put the alternator and new battery in. Installed a temporary digital meter next to the cig lighter.
Voltage11-25-13_zps22e8da86.jpg
 
I put the new alt in the CE, and it stayed at 14.4 for about 15 min. The old alt had corrosion on the rectifier where it screws to the alt. Green stuff just like you can get at the bat. Not much but maybe that was the problem. I'll check it out in the spring when it's a little warmer. Thanks for all the help and info TONYyyy
 
NoLimit95 said:
Mine starts in the morning at 14.2-14.4 and after running around a little, it usually rests at 13.8-13.9 and when shut off, it shows 12.6-12.8 and I have been watching it since I put the alternator and new battery in. Installed a temporary digital meter next to the cig lighter.
Voltage11-25-13_zps22e8da86.jpg
Click to expand...


I wish cars came with real gauges like that so you know what is going on in your car. Having a needle in a "Normal" range just causes more problems.

Glad you git the new alternator in Tony, I just got an estimate for $60 for replacing my bearings in my spare. Is your replacement a Motorcraft?
 
Replacement is a Delco. Old one FORD. The CE doesn't get driven enough, and it'll maybe last longer than me. Warm weather I'll install new tensioner, idler wheel and belt, that's sitting in the cabinet.
 
Lots of good tech in this thread! Just got my car yesterday and it had a dead battery, so I put a brand new battery in it. Driving it around the battery light would flicker at idle. Aaaaannnnnnddddd this morning I walked out to the car and went to start it and it just clicked. So looks like I will be buying an alternator this afternoon.
 
I use this to keep track of my batteries in my vehicles since many of them sit for weeks at a time-

http://www.harborfreight.com/digital-automotive-battery-analyzer-66892.html#.UzFTOYXLKzY

-This is nice because it measures internal resistance in the battery itself, the lower it is, the better the health of the battery. It is best to use this after charging the battery and allowing it to sit overnight to get a true evaluation of the battery's condition. It also is good since you can actually see if the connection at the clamp is giving a false reading. Remove terminals and get a reading, then do the same with clamps hooked up to see if there is a difference.


I periodically slow-charge the batteries using these-

http://www.autobodytoolmart.com/cra...p-18971.aspx?gclid=CLfe8NC3rb0CFY1xOgod920ANQ

Has three different charge rates, but I usually slow charge at 2 amps unless I know I'm going to use the car right away. I don't use it as a battery tender since it uses over 100 watts when plugged in, even without any load. It has the capability of determining if the alternator is producing enough power to run any and all accessories, and it will properly charge both conventional and AGM batteries.
 
You must log in or register to reply here.

Members online

No members online now.
Total: 352 (members: 0, guests: 352)
Back
Top