dead bird

Hi Have A 1985 Thunderbird And It Will Not Start. Have Changed Battery,cables,modular And Now The Start Won't In Gage Help Please.

Do you mean that the starter spins but doesn't engage the flywheel or that the starter doesn't spin at all? If the starter spins ok but doesn't engage the flywheel then you will have to replace the bendix drive on the starter. Take the starter out and check the teeth on the flywheel and the bendix drive on the starter to make sure they are still there. Your local auto parts store should be able to test your starter for you. If you are up to it you can use a pair of jumper cables to test the starter at home by connecting one cable to the positive post of the battery and the other end to the stud on the starter that the cable was attached to when it was in the car. Don't let this cable short to the case of the starter during this test. Connect the other jumper cable to the negative terminal of the battery and then touch the other end to a bare metal spot on the case of the starter. You may have to use sandpaper to clean a spot to get a good connection. Be prepared for the starter to jump and spin and sparks to fly when you touch the cable to the case! It's best to try to hold the starter down with your foot when trying this approach. The starter should spin and the bendix gear slide out to the end of the shaft. If you've never done this it might be wise to just take the starter to your parts store and let them test it for you!
If the stater doesn't spin at all check the relay between the battery and the starter. You should hear it click whenever you turn the key to Start.

You doing the above at home or having a shop do it is considered a "no load" test. It is possible that when testing this way the bendix will kick out and spin. But once under a load the bendix will slip. I have rebuild 100's of starters. If you have a good solid work bench and a vice, clamp the starter in the vice. Find a 2X4 about 3 feet long. Engage the starter and wedge the 2X4 between the bench and the teeth of the bendix and push upward quite hard. If the bendix slips, you will find out quickly. If not, it will chew away the wood and give a nice smoke show. This test has never failed me or the crew I worked with.