"going to install 3 relays, fuel, fan and pump. what gauge wire is safe to use to supply all 3 from batt.? also is it better to put relays close to the pumps and fan or the switches. thanks."
- I'm assuming that is fuel 'pump' ?
- What is the 'pump' you list last ?
Any pump is going to be a high draw item.
- Are you saying you are going to feed all 3 items off of ONE single wire, or each on separate wires ?
You need to run a SEPARATE ground wire from EACH power draw to a gang post next to the battery using the SAME size as the power wire.