Ok so I have the sct 3800 combo in a sc10 4x4. Ran great for a week. Recently installed a savox servo so I purchased a bec and wired it up via the instructions. everything worked fine other then at take off it had some bucking. Yesterday probably the 3rd lipo pack I ran through it I landed a jump and it just shut off. No throttle, steering ect. When I turn the esc on it blinks all three colors followed by a faint beep and the green light on the external bec is very dim....whats wrong with it? Btw im using a dx3s with sr3000t

All three LEDs flashing on a Castle ESC means it is not getting valid radio input. IT can be a problem with your receiver, the cable between ESC and RX and something broken inside the ESC. (I had one of the three wire leads broken off, luckily a friend helped solder it back.)
So first check with another receiver.

So I just messed with it a little more. When I plug the bec into the reciever the green light goes dim and or away. the reciever shows no power. Then if I move wire on bec around both the reciever and bec lights will flicker. Now if I disconnect the bec from reciever the bec green light goes back to normal bright green.....bad reciever? or bec?

Ok so reciever works in my other truck. Im guessing its a bad bec.

Have you cleaned the bec plug going into the receiver ?

Ill try to clean it but I honestly think bec its messed up. I noticed what looks like a small burn on the back if it

That is usually caused by pulling more amps than the bec is rated at. The reason could be many different things.

I wired it via instructions and sat peak off my setup from castelink

I wired it via instructions and sat peak off my setup from castelink

Check the amp draw of your servo, that under a load it does not exceed the bec's output.

So running a savox 1256tg and spektrum sr3300t what do I set cc bec to on castlelink?

Set it at 6v, the maximum voltage for your servo

Cheers

Yea thats what I have it at.

That seems to suggest a poor connection on those wires.

Yea it seems to be wire from bec to reciever. Not bec to esc wires/battery.