can some body help me i cant get my heater to blow it works on vent and defrost but nothing in high or low can somebody help me by telling me where to start with the problem i already checked fues and other no brainer stuff no lines are cut nothing could there be a relay or some other type of thing

Check the high and low blower relays. I am familiar with the 74-76 ACC but the main concepts are similar. Does the blower stop running when on hi and low? Does the air conditioning work on high and low, or does it fail as well? The high and low blower relays are sometimes mounted on the firewall, the shop manuals would help you here. Sometimes they are mounted on the evaporator case, and I'm assuming your evaporator case is on theengine side of the firewall.