Make sure the relay you use is rated for the amperage that goes through it. Most are 20A but they make 30A and 40A in the typical square type relay.
Which fuses not working??Starter relay needs changed constantly what is cause of failure; I tracted it down when I t urned the key had power but wouldn't turn starter, checked the fuses and found this one not working now it keeps blowing them I guess I change them and it works for short period of time