I have a 2001 DHS Caddiliac i just recently brought .i was told i needed an altenator.i replaced it and a new b .i drove it for a month and a half.i let it sit for two days now it want hold a charge
You might also have a small electrical drain on the battery when it's off. So if you let it sit for too long, the battery dies. If you drive it daily, the alternator can keep the battery charged up, in spite of the overnight drain. But first thing to do is check that the battery itself is good, go to a car parts store like Autozone, Advance, or O'Rielly and they'll check the battery for free. (all the major stores do this).
See if the compressor for the rear air shocks is coming on when the car is off. My '94 Fleetwood does that. HTH. -Jim
Looking for a Used Cadillac in your area?
CarGurus has 81,606 nationwide Cadillac listings starting at $1,295.