Speed controller wiring

Hi all out there. I wonder if any of you can help me. I am at the moment building a submarine. And I am now at the electrical part. The sub as two motors, a water pump and a water inlet/outlet valve. I have wired the water pump to a speed controller and the valve takes it’s power also from the speed controller. On the table top it works find. The problem comes in when I add the 2nd speed controller for the motors. Then this is what I get. The pump and valve work ok. But when I try to get the motors to turn. The speed controller led lights up, so it’s getting the command. But there is not enough power to turn the motors. The wire from the battery to the speed controllers is very thin as it connects by a waterproof connection
So my question is. Do I need to forget the waterproof connection and use thinker wire through out the build. The speed controller wires are around 4mm thick. What would best wire thickness to use on this 12v system. And is there a better waterproof connection with thicker wire available in the uk. Thanks. Michael

Michaelc wrote:Hi all out there. I wonder if any of you can help me. I am at the moment building a submarine. And I am now at the electrical part. The sub as two motors, a water pump and a water inlet/outlet valve. I have wired the water pump to a speed controller and the valve takes it’s power also from the speed controller. On the table top it works find. The problem comes in when I add the 2nd speed controller for the motors. Then this is what I get. The pump and valve work ok. But when I try to get the motors to turn. The speed controller led lights up, so it’s getting the command. But there is not enough power to turn the motors. The wire from the battery to the speed controllers is very thin as it connects by a waterproof connection
So my question is. Do I need to forget the waterproof connection and use thinker wire through out the build. The speed controller wires are around 4mm thick. What would best wire thickness to use on this 12v system. And is there a better waterproof connection with thicker wire available in the uk. Thanks. Michael

Many speed controllers have a BEC in them as well. If yours do, you cannot have two BEC going to the receiver. You will need to disconnect one of the ESC power to the receiver. To do this remove one red cable going to the RX.
As demonstrated here on my Gato:
https://forum.rc-sub.com/forum/builder-threads/1877-revell-gato-1-72-newbie-no-more-part-duex/page21