Looks like thats a Castle Creations Mamba Monster 2 ESC. Castles webpage has this to say about a flashing yellow light error code.
"Flashing Yellow ESC is seeing a neutral signal. If it does not change then you are either plugged into the wrong channel on the receiver or there is a problem with your radio."
Is the ESC plugged in to channel 2 of the receiver?
Heres the MANUAL for that ESC. Id try to run through the calibration steps and see if that helps.
Follow up question...Whats going on the the ESC fan wires? The negative fan wire looks like its been removed from the original plug and connected to the positive main power wire. Unless I'm misunderstanding what I'm seeing in this pic.
I don't understand what you mean by channel 2 .. it has a spot for steering, throttle, bind, aux. I've tried to calibrate it but it doesn't even do that. No the fan is in its proper spot
I think he said channel 1 is steering and channel 2 is throttle. Not sure what is confusing about that. When looking at the receiver, the bottom port is channel 1, which is for steering. The 2nd port from the bottom is channel 2, which is for the throttle. So plug the steering servo into the bottom port (aka steering port, aka channel 1 port), and plug the cable from the ESC into the 2nd port from the bottom (aka throttle port, aka channel 2 port).
I'm saying Channel 1 is steering, Channel 2 is Throttle, Channel 3 is also generally the bind channel and is above channel 2, and the spot above that is the AUX/BATT channel which isnt really a channel just a place to power things from.
You said your receiver "has a spot for steering, throttle, bind, aux." So I was telling you what channels each of those were in the order you listed them in because you didnt know.
steering channel is not steering its channel 1..thottle is not throttle its channel 2 and channel 1 is steering channel 2 is throttle just so you know,,lol