Tbird won't start

90 thunderbird sc won't start.Every time I try to crank it , it looks as if the battery is dead. But when I test the battery it shows a full charge. I have replaced the starter and the starter relay. Where else should I check before going to get a new battery. THks

How are you testing the battery? Be sure the battery cables aren't corroded.

I used a multimeter to test them.The battery cables are cool. I took the battery off and charged it up. And it was working fine. I tested the alternator too.

Does it turn over at all- even slowly? After you've charged the battery, turn the headlights on for about 10 sec and then shut them off. Remove the fuel pump fuse so that the car can't start. Hold the voltmeter on the battery while you have someone try to start the car for 10 sec and see if the voltage drops below 9.5V. If it does, replace the battery. Your battery dealer has a load tester which is a better test of the battery but this will give you an idea of its condition. If the battery checks out ok then connect your voltmeter from the Pos battery terminal (pos lead of meter) to the relay terminal at the other end of the cable (neg or com lead of meter). Have someone try to start the car while you watch the meter. This tells you what the voltage drop of the cable from the battery to the relay is. If it is greater then 0.5V then the cable or connections are bad. Make sure all the other connections are clean and tight and let me know the results from the tests.

I found out it was the battery.I took it off and put it on my charger. And once I charged it full. I disconnected it and it started slowly losing volts.It would wind all the way down to 11.32 volts. And stay there at a constant. Thks for your help bro. I really appreciated it.