Hello everyone! Let me give you the details, hopefully someone can help me get this car out of the driveway!

We just got a 98 sable wagon about 2 weeks ago, we love it! We were
told from the seller that it recently had a new battery and new
alternator. Has ran great from the start. Until yesterday!
I got in it to start it and it took longer than usual. lIke
"wuuuhh wuuhhh wuuhhh," but then it started up. Didn't think anything
of it, it wasn't that cold out, maybe 40 degrees or so. It ran
fine for the hour and a half I drove it. Turned it off for a half
hour or so, got back in, did the same thing, took like 4 or 5 seconds
to start again. This happened again the same night, each time
taking a little longer to start up. Luckily I got home just fine.

This morning my husband says it won't start. It does
the wuuuh wuuhhh, but a LOT slower now, and he says it won't turn
over. He doesn't think it is the starter. I don't think we left
anything on over night, which doesn't make sense even if we did because
it started earlier yesterday, not just this morning. My husband
recently installed sirius radio in the car, but we always turn it off
before we get out. Any ideas? Tune up maybe? We don't
know. the car has 104000 miles on it if that makes a
difference. If it is the alternator, again, what could be blowing
out the alternator? Thanks in advance!

Have the battery and alternator checked to be sure. If they check out okay then you seem to be having excessive starter draw and may need to replace the starter. I would make sure the problem did not start the same time sirrus was installed.