Car won't start...

I have a 99 Sunfire GT 2.4L. The Starter only makes clicking sounds and won't turn over. Sometimes the Starter will turn over and the car will start up, but very rarely.

So far I have:

-Changed the Starter with two different ones. (one used and the other one re-built). I bench tested the two I bought and the original one also and they all tested good.
-Tested the battery with a multimeter and had a load test done on it. Battery is good.
-Tried boosting the battery with another vehicle, and it didn't help.
-Hammer on the starter, while the key was on. That seemed to get it going a couple of times.
-Visually inspected the wiring and fusible-link, and it looks good.

I don't understand how all three Starters tested good, and do the same thing (no sound or some clicking sounds), but yet, banging on it gets it going. I've come up with the idea maybe it's not getting enough power, but the battery tested good (12.6v) and got the same voltage reading at the Starter.

I was gonna try maybe changing the Relay. Does anybody have any other idea's or links about the electrical system in the car starting system?

indeed they do have a relay-actually when i worked at the gm dealer i remember something about a recall on this exact relay-the changed the design and location of it-but i am no tech so i can't be specific. i think they also have fusible links going to the starter-i would check all these for continuity. sometimes the cheapest things cause big problems

Thanks for the response. Sorry my grammar was so bad in my first post. I had about 2 minutes to sign up and post before my ride got here.

Anyways. There is a Fusible-link in the wiring from the Starter-Relay which goes to another set of wiring going to the rest of the vehicle. The Fusible-Link looks good. Besides, if it was the Link or any kind of fuse the starter would do nothing and be dead, right? This, and the other two Starters atleast made clicking sounds (sometimes) or turned over (rarely).

So I'm taking a break from looking under the hood and gonna spend some time learning how to properly trouble shoot the electrical part of the starting system and figure out my plan of attack with a multi-meter. I'll post again when I finish trying that.

Any other comments or idea's are much appreciated.

I've learned that there was a factory recall on my model Sunfire for the Ignition switch. I guess it was causing to much current to flow through the switch and could cause a possible fire. I guess they install a Relay between the Starter and the Ignition switch.

http://www.automotive.com/1999/49/pontiac/sunfire/recalls/18414.html

I'm sure the vehicle had the work done on it, cause there is a Relay mounted in a wierd spot (beside the hood latch) and there is no mention of a Starter-Ignition Relay in my Haynes manual. So i'm gonna try switching out the Ignition Switch and see if that fixes the problem.

Well, I decided to change the Ignition switch first. I changed it and the car started up no problem (friday). A few hours later I tried the car again, no problem. The next morning I tried again and the car clicked a few times than dead. I waited about 6 hours and tried again and the car started up no problem (saturday). The same thing happened today (sunday).

I live in Canada and so the weather right now is cold in the morning (-1 degrees celcius) and in the afternoon it warms up (+10 degrees celcius). So i'm starting to see a connection between the temperature and the car starting. I've also notice though that when the car does start it starts up fine (no clicking), but when it's cold it clicks a few times than dead.

How about ground connections?

How about ground connections?

The ground connection from the battery's negetive terminal is dirty and a bit corroded but still tight. I don't believe that is the problem.

The past week the car has been starting up good. Even this morning when it was below freezing. I've bought a new car this past weekend, so I just have this one sitting until I know it's gonna start fine regularly, than sell as is.

Well not to sure about sunfires but my old tempo i would a clicking sound and it wouldn't turn over was my selindo switch <--not to sure how to spell it. We jumped it to get it to start.