u/211XTD

So I have a 1998 Buick Park Avenue which was running fine before this happened. I had just had the muffler, exhaust, some pipe and the EGR valve replaced as the check engine light was on. After all that the check engine light remained on and garage could not figure out why, said they tested everything even the electrical system and alternator which was all fine. Car was running fine the next few days. Then the last time I drove it I noticed, when I was inside the house, the wipers were still running with me and the keys inside. I turned the wipers off and the next time I went to start it nothing worked. I took the battery in (4 month old) and it was drained so they charged it and tested it and it was fine. I bring it home hook it up to the car and still nothing. I plan to sell it and be done with, we have put a lot of work into it already (professionally not personally), but would like it to start before I put it on the market. Car has less than 75,000 miles.