I've replaced about 4 starter relays on my 70 Challenger. Some new ones may be worthless because when I buy the replacement it works for a little bit, then it goes out again (even using different suppliers). I have used either a screw driver to make contact on both screws to start it or a remote starter cable, and then I can use the key thereafter, until it stops working again.

Should I be looking at another possible problem? All wiring seems to be intact, ignition switch seems to work fine, etc.

Any leads are appreciated.