The problem is the car wont start intermittently.

Yes alternator output been tested puts out 14.5 volts and no lights on when engine is running. When its starts its runs great.

The only other thing it could be is poor battery connections! Otherwise a "jump start" would not be necessary!!

the battery cables been replaced and connection is tight. When its cold starts right up I only have problem when the engine is hot. I'm thankful for any help its been going on for two months its driving me crazy even the mechanic is puzzled.

I am having the same problem with my car today. It was working fine then I drove I picked it up at the mechanic this morning. Drove 3 miles home, parked it, came out 5 hours later it wont start. I was upset since I had just blown $1000 in repair this morning. It just made a click sound when I put the key in and silence, radio works and lights work but it wont start. I did some research on the car, thinking maybe the starter needed to be replaced and it seems there are many people having the same problem with their car too and mechanics seems to miss this for some reason. According to st162.net the problem is the small wire going to the starter. It states to get a 12VDC 5-pin relay SPDT 30/40A with a metal bracket which is about $7 at autozone. The relay acts as a power booster for the small wire that goes to the starter. Apparently, everyone has replaced battery, starter, alternator, spark plugs, etc but continues to have the problem until they replaced or installed the relay which solved their problems. Go to st162.net to electrical forum, then to: how to section, click 4th generation starter problem and you will get the info. Hope this helps. I am going to try that first before I go throw away another grand into repairs for things I don't need.