Why cant i use my rc cars xl5 esc or fs-gt2 tx & fs-gr3c rx?

i have a titan 12t 550 motor with xl-5 esc, airtronics servo, sanyo 7 cell battery, fs-gt2 controller, fs-gr3c receiver, the tx/rx are brand new as well as the servo & the motor/esc combo was a pull from a brand new only driven once traxxas slash, all running in a gold pan rc10 worlds tub with everything swapped with aluminum parts & stealth tranny, i get a fast flashing red light on the rx whether the esc is on or not & i can get into sync mode on the esc but cant sync with rx, it says i dont have to do anything just plug in & go or at worst reprogram esc which i can do, i cant get the green light to stay on, i am sooo confused please help! thanks!