Replace my alternator and charge battery to 93% and replace the negative battery post battery still drains in my 2000 cadillac deville

Check connections to the battery posts, connections to solenoid on starter , test alternator by checking voltage at battery posts while running the engine (parts stores will do it for you).

bad batt..alternator..or wornwire that charges. Chec all connections for dirt and titeness. Cud b a fuse tu. Charginwire is at back of alt to the batt

Sounds like an alternator problem...or voltage regulator inside the alternator

I suspect parasitic draw. All vehicles draw some power from the batteries when the car is shut off. Certain accessories such as clocks, radios remote door openers and alarms always need power. The normal power used is called parasitic draw.

It is always a very low draw so it doesn't run the battery down. If you install accessories like shortwave radios or plug things like inverters and portable refrigerators into the accessory socket and operate them too long without the engine running you can drain your batteries to the point where the engine won't start. If there is an electrical short in the vehicle or a malfunctioning accessory it could be drawing much more than its normal load causing a drain on the batteries. If you leave your door open and the inside lights stay on all night you could drain the battery down till the car won't start.

Here's also a good resource for your car specifically on narrowing down the cause of the drain.

How old is the battery? I learned at Sears while working there in the battery department that the average life of car batteries is about 3 years. So, after that, batteries lose a significant amount of their performance CCA or cold cranking amps, and may have to be replaced on a pro rated basis after that period of time, on average.


I put a diehard platinum battery into my 1997 Cadillac Deville Limousine for about $189.99 plus tax and it has a 4 year replacement warranty due to bettery construction.

However, if you get Walmart's best Maxx battery, they have a 3 year replacement policy and they charge about $79.99. I put that into my 1990 Cadillac Deville.

Good luck on resolving the battery drain problem with a good alternator.

built in.

You should check for voltage draws when the vehicle is off... Disconnect the negative battery termal, Pull dome light fuse,and connect a light or volt meter between the two.

common offenders are alternator diodes. These fail and cause drain.

Then you have to check, circuit by circuit, until you find the offending system.

Also, before doing anything, disconnect negative terminal and see if the battery is still fully charged after a few days...

SOUND LIKE ALTERNATOR NOT CHARGING BATTERY.BEFORE BUYING A NEW ALTERNATOR CHECK ALTERNATOR WIRES AND FUSE.IF YOU HAVE TO REMOVE ALTERNATOR.TURN OFF RADIO BEFORE REMOVING NEGATIVE BATTERY CABLE.SO YOU WONT LOSE PLAYING CODE.

you need to do a load test on the battery first to verify its good,charge battery fully,turn headlights on high beam,wait for five min and crank engine with lights on,see if you still have a good cranking time,if you don't replace battery,if you do charge battery up to full again,check voltage at battery post with a multi meter,
should be 13 volts at minimal,now turn headlights on ,heater on,and flasher on and pull in gear,have a friend check voltage at battery to see if it is staying above 12.50 volts,if it is below 12.50 the alternator is not putting out on a load,replace it.if these check out good,check for dome or hood or trunk light not shutting off ,or something else draining battery.

So you have a new alternator. I S IT CHARGING ? If the answer is yes , and the battery still dies, I would say there is a 12 volt drain in the electrical system. Hope this helps