It is important to maintain a vehicle even if it isn't being driven, but if you have a car that has been ignored for a year or more, you may want to inspect a few things before you try to start it up and get it back on the road. If the car has been stored indoors, it will likely have fewer issues than one that has been subjected to the forces of nature, but you will still want to check it out before taking it for a spin.
First thing's first - perform a safety inspection. Check the hoses and belts for signs of damage and wear. If they are cracked, torn or otherwise in disrepair, you will need to replace them. Climb inside the passenger cab and have a look at the safety belts as well. Make sure the belts are not ripped or frayed and check that the locking mechanisms work properly.
You should also look at is the car's fluids - all of them. The reservoir tanks for transmission fluid, oil, coolant and other fluids should be marked at the optimal level. If any of the fluids are below their respective lines, this may indicate that there is a leak. You should also inspect the liquids themselves to determine if the fluids need to be changed.
Next, take at look at each individual tire. Use a pressure gauge to determine the air pressure in each tire, and consult the owner's manual to find the optimal pressure setting for your vehicle's tires. If they are low, fill them up and move on to the next item on your checklist. Don't forget to double back and measure the tire pressure later. If it drops significantly in any tire, there may be a leak.
You should also check the electrical components and interior accessories to make sure they are working properly. Turn the car on, but don't start the engine just yet. Test the lights, radio, wipers and other equipment. If something isn't working properly, this could mean that the fuse is blown. The cover of the fuse panel may have a diagram that denotes which fuse controls what accessory, but if not, this information can also be found in the owner's manual.
Now it's time to start the engine. Pay close attention for any unusual sounds or sensations that could indicate issues with the engine, transmission, steering and other aspects of the vehicle. Pump the brakes and pay attention to the pressure the pedal offers. If it feels at all mushy or doesn't resist much when you put weight on it, there may be a leak or air in the brake lines.
You will also want to check the exhaust system for leaks. One way to do this is to cover the exhaust pipe with a rag and if things are running smoothly, it will be difficult to stop gases from exiting the pipe. If you hear a hissing sound when the pipe is covered, you may have a leak somewhere in the exhaust system. You will need protective gloves as the exhaust pipe and the gases coming from it will be hot.
After you make any necessary repairs, you can take your vehicle for a drive. However, if you are unsure of the vehicle's past, such as if it was given to you by a friend or you bought it used, you will want to conduct a more thorough inspection before attempting to drive it. There may be preexisting problems that are not easily noticeable in a basic inspection.