Have you compared the size of an external bec and an internal bec? Also have you tried the tests with the switch removed and hard wired? I am not sure but if the bec gets it power directly from the switch and not some sort of internal relay,then a crappy switch could be part of the problem.

The only BECs I've compared are not similar in amperage, so I wouldn't expect them to be similar in size. The Castle BECs are 10A or more whereas the built-in style is 3-5A.

I haven't seen the wiring diagrams, nor have I disassembled any of the ESCs I have that contain BECs, so I can't be completely certain. That being said, I can't image that any of the manufacturers would have all of the amperage running through a switch. General practice for electronics I've seen is to have the switch just complete a circuit to power up the unit.

Thanks for the link and the tip. :-)

I agree with ufo regarding the switch, that has been my experience with several ESCs over the years. The switch is at battery voltage, and low amperage. It is not part of the BEC power path, it just turns the circuit on same as the motor drive portion of the ESC. I ran several KO FET servos for a long time that have a separate power wire going to the battery, I frequently spliced it into the switch for extra error proofing, why I am familiar with the switch voltage. I don't believe the switch is contributing to this issue.

I don't know. For Tekins on 1s applications we often wire the receiver pack into the switch. It works great but that would seem to indicate to me that the BEC power is indeed going through the switch, at least on Tekins.

Good point wingracer, I wasn't thinking of 1S use. But if it works great that suggests the switch isn't causing too much trouble, at least on a Tekin?

Side question if I may, what receiver batt do you and/or most guys use? 2S lipo?

Yep, small 180mah 2s lipo wired into the switch so you just have the one switch to turn everything on/off. From what I hear, this only works on Tekins and one or two other speedos so perhaps the others don't send BEC power through the switch but at least Tekins do.

Oddly enough most of the ESCs I was referring to were the “other” Tekins, 600, 411P &G, 420F. And a Novak T4. Thanks again for the info Sean.

Problem is the ESC (Castle ESC's have a weak BEC) I run savox on all my cars, a Summit with a SC8WP and a 30kg Savox servo, and a Tekin RX with a Savox 1267 in my SCT410 neither need external bec's, caps or anything else. All using Airtronics rx's