I'M HAVING PROBLEMS WITH KEEPING MY S40 BATTERY CHARGED AFTER INSTALLING NEW ALTERNATOR

1985 WOW ! does it run at all ? if it does , check battery voltage, should be between 12---14 volts, check alternator also, a parts store can do this for you ! is your regulator outside your alternator ? cause most new alternators have them inside the alternator ! just thinking out loud, but stranger things have happened ! are these new parts the correct ones for your make & model ? battery terminals clean, tight ! make sure all GROUNDS are good ! very important ! what condition are your battery cables ? is your BELT good, tight, not slipping !!! sure your starter & solonoid OK ! not shorting out, from dirt, grease, oil, etc., all fuses OK! I think we covered it, take your time, go over what I mentioned, see it you find the problem, good luck !

That suggests that the problem is in the harness, something in the connector or wiring is causing an open circuit. You will need to have the circuit tested to find the fault. Ford alternators have known connector issues & new aftermarket connectors are readily available at most auto parts stores.

your engine lamp could have blinked for many reasons, as far as your alternator and battery system, make sure the battery is fully charged, when it is, you should get a reading of 12.4 volts, checking it with a volt meter doesn't necessarily mean thats charged fully as far as amps, you should have your battery LOAD tested to make sure it can fully charge and hold that charge, once its charged the alternator should keep it that way , if you test the posts with a meter while the motor is running you should get a reading of anywhere between 13.5 to 14.5 volts, when checking the battery , make sure all connections are clean and tight

Go to web site WWW.HMASERVICE.COM and register your vehicle by VIN #. You'll then have access to shop manuals, wiring diagrams, technical service bulletins, illustrations, etc.
Provided there is no problem with the vehicle's wiring, find out what the charging current is to the battery. I've seen batteries which TEST good, but when under a CHARGE short out internally.
Example: Tested a battery & charging system on a Hyundai Elantra, the battery tested "Healthy" but indicated there was a CHARGING SYSTEM PROBLEM. I checked the battery voltage while the engine was running and found the battery voltage at 14.3 VDC (which was normal). I then used a Digital DC Clamp meter arount the positive (+) battery cable & found the battery was charging at 70 Amps!.. it was supposidly already fully charged (should have only been taking 4 to 6 amps when fully charged).

Best guess without looking/diagnosing the vehicle myself

Maybe this will help.

it sounds like the system is'nt charging.if you have a volt meter you can check it
with meter set on dc volts check the charging by putting the red lead to + & black to -
on the battery.reading should be 13.2 - 14.5. .if it reads 12 - 12.8 its not charging. check the red
wire on alternator to see if you have 12v
good luck

Hi: The Specs on a Battery Range From 600 Cold Cranking Amps to 750 Cold Cranking Amps. So if you have a 800 Cold Cranking Amp Battery installed then you are at or Above The Required Amperage Needed.Unless your Running Extra Lighting or Accessories. and you have to consider your Alternator Out-put as well.You need a Alternator that will Keep up the Charge on Your Battery. So in a Nut Shell the More Add Ons you Have the More and The Harder your Alternator has to Work to Try and Keep Your Battery at a Full Charge . A Fully Charged Battery you'll have 2.1 Volts per Cell = 12.6 . Hope this has helped you, Please Let me know how I've Solved your Problem with my Solution. Thanks and Good Luck From d_hubbs

Check the function of the alternator. Charge the battery with a battery charger or jump start the engine. While the engine is running use a voltmeter to check the voltage at the battery posts. Red to + and black to -. You should have between 13.5 − 16 volts. If you do not the alternator is bad or the drive belt is loose. If the alternator checks ok then something is on that is drawing power from the battery and running it down. Check under hood, trunk, glove box, and interior lights. Can also be a brake light switch causing the brake lights to stay on. In rare cases it can also be a stuck relay such as a power window relay. From you description I think you will find the alternator is ok and your problem is something is on and running the battery down.

When the new alternator was installed did you perform a charging test to ensure it works properly. If it's not the alternator may overcharge the battery causing corrosion to the posts and possible cracking of the battery case. If you don't have the tester at home most auto parts stores can connect theirs and it usually is free.

Good luck to you

Check/inspect quality/condition of cables between the alternator & the positive (+) post of the battery. Also check quality/condition of ground cables & straps between battery negative (-) post and chassis and to engine block. One final check is the alternator's regulator connection between it and the UH (underhood) junction box (fuse & relay box).

1.You need to install a Fully charged battery, before you install a new alternator. Otherwise it will burn the alternator up.

2.I read what you typed about installing a new battery. Was the new battery fully charged, and was it installed before the new alternator?
No?
See number 1 above.