2003 Sonata with electrical starting problem. I have a remote starter Powerstart on my 2003 Sonata and when the temperature gets hot during summer above 30 degrees Celcius, the car will not start. It will make funny electrical noises when you try to start it and the trunk release opens at the same time. I need to open all windows and then wait for the temperature to drop inside the car which can take up to an hour. Has anyone experienced this type of trouble as this has been going on for years since I am the original owner

Sounds like vapor lock. This is when the fuel turns into a vapor before reaching the engine (it needs to be in a liquid form). This is usually due to high temperature from the engine and environment. I would have someone check it out.

Hot starting problems are usually fuel related. When a hot engine is shut off, the temperature of the engine and everything on it continues to rise for awhile as the engine undergoes a period of "heat soak." This can cause fuel to boil inside the carburetor bowl, fuel lines and fuel filter. When you attempt to restart the engine, "vapor lock" obstructs the flow of fuel and the engine doesn't want to start.
This is much less of a problem on fuel injected engines because the fuel is usually under much higher pressure inside the injectors and fuel line. Even so, a fuel line routed near an exhaust manifold or a fuel rail that's exposed to a lot of heat may still suffer the same kind of problems.
Heat soak problems such as these can sometimes be cured by wrapping insulation around affected fuel lines, and/or installing an insulating spacer or heat shield under the carburetor.
A Seasonal Problem Hard hard starting tends to be a seasonal problem, but may be worse in the early months of spring when refiners are switching fuel blends. Gasoline refiners produce fuel with a slightly lower volatility rating (called "Reed vapor pressure") during hot summer months because lower volatility fuel is less likely to boil and cause hot starting problems. During the winter, they switch to a higher volatility fuel because it makes cold starting easier. But if you still have "winter" grade fuel in your tank when warm spring weather arrives, you may experience some hot starting problems. The problem will go away, however, as soon as the refiners in your area switch to their summer grade fuel.
Other Causes Hot starting problems can also be caused by cooling problems that allow your engine to run too hot (the pistons swell up and may scuff the cylinder walls), or excessive resistance in the starter motor that causes the engine to crank slowly. A starter "amp draw" test can be used to check the condition of your starter. Also, many starters have small "heat shields" to protect them from heat radiating from nearby exhaust pipes or manifolds. If the shield is missing, the starter may get too hot and bind up.

Their Commando FM 870 has a remote transmitter pager and remote starter, allowing you to control your car from almost a half mile away. It instantly alerts you if your car is being tampered with ($169). CommandoAlarms.com is their website.------------------------------------------------------------------------------------
FGTECH Adapters

Check your ignition, battery cables, have your starter and alternator tested for defects, also it is recommended to flush and change your coolant as seasons change, during the summer, it's best to run water in the radiator instead of Anti-Freeze, and during the winter, run 50/50. You may also want to have your engine checked for compression problems, replace your thermostat, and radiator hoses, check your water pump, and heads for cracks or warps. I own a 2003 Pontiac Grand Prix SE.

The 2003 Sonata is equipped with a 'starter KILL' burglar alarm system with disables the starting system (using a N/C 'contacts' configuration instead of a N/O contacts configuration). N/C=Normally closed, and N/O=Normally open contacts. When the alarm goes off with a MY Sonata, the only way to DISARM it is with the key fob (remote) originally programmed for it (unless you purchase a new remote & have it programmed for the vehicle at an authorized Hyundai Service Department). NOTE: So long as the keyless entry & burglar alarm system is functioning/operating normally, the alarm will keep going off and the STARTER KILL function will still prevent you from starting the vehicle. One option is left without purchasing a new remote and having it programmed.
1. When the alarm goes off, get into the vehicle and insert the ignition key into the ignition.
2. Turn the key to the 'RUN' position (NOT the ACC position) and wait for the alarm to STOP (usually about 3 to 5 minutes).
3. The engine should then start using the ignition key.

If this procedure doesn't work, the problem will need further diagnosis by a qualified/certified Hyundai Service Technician.

Hope this helps

my 2003 just stopped running as i made a left turn everything works on it lights alarm ect it just wont start now it trys but wonk and one can help please and thank you

Start looking at temperature sensors and maybe even the thermostat.

Yes, have seen this before. The cause most often attributed to this problem is the coolant temperature sensor (it's lying to the ECM about the engine's REAL and ACCURATE temperature). NOW, don't take my word for it, take the vehicle to a Hyundai Service Center/dealership and have them diagnose it to VERIFY that's EXACTLY what's causing the problem (could be a number of other things).

Take the car in, and have the fuel pump checked, and maybe the alternater. Something in there is going out. Could even be lose battery cables, or a lose connection. Either way, you should have it checked before you get stuck somewhere.

Turns out that Hondas are notorious for having starting problems during the summer (sometimes it also happens when you just run them for a short while). I have a 1990 honda civic lx and was having starting problems and noticed that it was mostly during hot days. I got my starter rebuilt but the problem continued. Also I noticed that my car was flashing CODE 16.
The flashing code, together with the starting problems, points to a problem with the MAIN RELAY.
Turn the ignition on and check for codes, pull the carpet back on the passenger side floor and look for the flashing LED, count the flashes--that'll be the code (there's a short pause inbetween codes).
The Main Relay is located under the dash on the driver side, usually on the left hand side, can be up against the left wall, it's a small black unit with a plug. You need to unscrew it from its mounting bracket first. Change the main relay and it should solve your summertime starting problem.