You never know what those quick lube guys do! My son took a Jeep in for an oil change. Told them to check all fluids-yeah, sure! Guess they forgot. Next time he went for an oil change, they did check and told him the transfer case was completely dry.
Don't think they did anything to cause that on your car, though. Don't even know how that could happen. Is it random blinking, or car alarm-type blinking?

It sounds like they may have just bumped a connection loose. You could call the shop you had your oil changed at and explain your situation and they may be able to have you drive back to the store so they can double check any connections they could have bumped. Its pretty common, also you could also try going to advanced auto or auto zone and most of the time someone would be glad to help check them too. I always get great service or advice from those stores. I guess it depends on the "willingness" and knowledge of the sales rep. as well as how busy your local stores are when you go in. Hopefully that got you pointed in a few helpfull directions to start with.