> Why do I have to jump start my car every time I want to start it, even after I let it run for 30 minutes?

Why do I have to jump start my car every time I want to start it, even after I let it run for 30 minutes?

Posted at: 2015-01-07 
Check the large main alternator fuse in the under hood fuse and relay box by the battery, There is also what looks to be a 10 amp alternator field coil fuse according to this Q45 diagram for your car (top E8 white wire).

Edit to add, see the alternator resistor (top N54 white / red), the alternator field flashing resistor may be bad.

You can easily check for a bad battery drain with a battery charger that has an amp draw meter by disconnecting the battery positive and seeing how many amps the car draws on the charger when off with the dome light off. If you see more then a wiggle, the car may have a drain on it. A new car battery can hold a 1 amp drain for days and still start up fine.

http://i78.photobucket.com/albums/j106/q...

It could be the starter motor, but your mechanic probably would have detected that. Most likely something is draining the battery while the engine is off.

Drive around and get the battery good and charged up. Then when you get home disconnect it so that nothing can drain it. Then the next day re connect it and see if your car starts right up. Detecting what is draining the battery can be difficult unless there is an obvious light that stays on. You could pull a different fuse each night and try to figure out which circuit the drain is on. If you pull a fuse and it stops the battery drain then that is the circuit you need to look at.

When you get the car started, disconnect the battery while the car is running, if the car dies out, then it is your alternator, it needs to be replaced. Now if the car stays on then there's the possibility that your starter solenoid has gone bad, tap the starter with a small hammer or tire iron from underneath the car while another person turns the ignition over without having charged or jump start the vehicle, this procedure will rule out battery and alternator.

If the battery and alternator are good, you need to check for something draining the battery when the car is turned off.

It is likely there's a problem with your starter or battery

you could have a bad alternator that prevents the battery from being charged.

I had simler issue. I just bought a new alternator without ask the garage man.it worked for me. Try it in a differnt garage. Its stressful when car doesnt work, get it pver and done with

the battery

Thanks everyone for your knowledge and help. It was the alternator and the car starts and runs fine now.

Come on baby you can run right.

I will let the car run for more than 30 minutes and drive it around town. When I park it after doing this for more than a few hours I have to jump start the car again. I have brought it in many times and the altenater and starter are fine from what the mechanics tell me and I have replaced the battery 3 times but I know that this is not what is wrong. Somebody please help? It is a 1994 Infinity Q45.