Another Electric Fuel pump wiring question.

Dubob said

The power (10ga) wire feeding the fuel pump you want the circuit protection to be as close to power source as you can get it. So if coming right off the battery I would install a fuse from battery to supply wire. I say fuse because if it pops an actual circuit breaker may reset and if there’s a problem I wouldn’t want that. As far as the control of the relay for the fuel pump I’d also fuse that before the control switch then to oil pressure switch then to the relay. The goal is to protect as much of the system wiring with the fuse as possible. That’s how I look at it. I’m sure someone else will be along that’s got more input.

Click to expand...

A couple of further observations . You want to use a breaker or slow burn fuse on a fuel pump. This is because they are more tolerant of power surges where as a standard fuse will blow with the slightest surge over it intended voltage. The same is true for electric fans. Also there is no point in fusing the circuit from the relay to the pressure switch. That is a trigger wire and has very little power running in normal operation. In my opinion you don't want to insert a failure point on your trigger wires because the chance of frying them if the main circuit is fused is limited but it will most likely create an additional location for gremlins to manifest themselves down the line. Also the circuit that feeds the switch is already protected via the ignition circuit