Need any advice, please

Car’s engine and battery light stay lit. Took car to be diagnosed and was told to replace accelerator and battery. Both were replaced but lights are still lit, although the engine light goes off and on throughout the day. Car seems to be driving okay except engine fan turns on immediately and continues to stay on 2-4 minutes after the car is turned off. The fan comes on as soon as I start the car and car is not even in hot weather. Any advice would be greatly appreciated, thank you in advance.

I;m sorry, I meant I replaced accelerator and battery, not Engine!

That CEL (check engine light) is just a kid in class waving her hand trying to get you attention because she has the answer. You need to have the codes read. Some places will read them for FREE. Try Autozone or Advanced Auto Parts. Get the exact code (like P0123) not just their translation into English and post it back here.

Replace Accelerator ???

I’m guessing alternator.

They replaced the alternator, not the accelerator. No problem, we all know what you meant.

Likely you have two separate problems. The behavior of the engine fan is probably due to a faulty coolant temperature sensor. This is an inexpensive part, so a mechanic would likely want to replace it purely on speculation. Allow the repair.

The behavior of the warning lights is more mysterious. It may be as simple as a bad electrical ground connection, or it may prove to be a problem very difficult to track down. Possibly even a fault in the computer, as I found in one case. Then a temporary swap of the part with one from an identical car verified the problem. We will see how clever is your mechanic.