Marcocaster
Try switching the leads from the Vantec to motors. If problem now moves to other side (left side only runs in reverse) may not be ESC. Test motors with just a battery as well - do they both run forward and backwards ok (reverse black and red wires on battery) when connected to battery? Check connections to receiver - nothing loose. Can you test a different radio/receiver combo? Do tracks on both sides run smoothly with no snags or jamming?
Could be EMI (electronic noise) interrupting or creating spurious radio signals. Is receiver located near motors or ESC? Perhaps move away from motors if so. Check antenna of receiver (wires pointed correctly if it has external wire antenna).
I personally like the Sabertooth's ESC for ease of set up though. It wouldn't hurt to have a backup ESC to the Vantec.
Bob
Last edited by RC_BobM; 09-05-2018 at 09:24 PM.