I have a 2003 Chevy Malibu - periodically, they turns signals decide not to work. I don’t know that one thing in particular causes them not to work. What could be the issue and is this something I can fix easily (I’m a novice), cheaply and quickly myself? I’m planning on selling this car privately in the next few months and I don’t want to drop anymore money than needed.
GM multifunction switches of this era have a higher than expected rate of failure. I replaced the multifunction switch (turn, cruise, wipers, etc) on my 2000 Blazer 3 or 4 years back. The switch cost ~$200 and took a few hours to replace. It’s not something you want to guess at.
Before replacing the switch, I used CRC Electrical Contact Cleaner to clean the contacts at the base of the switch on the steering column. The turn signals worked for a few days after the cleaning, perhaps you will have better luck.