Question about the amperage rating on the SPST toggle switch if the fuse is a 20Amp. The attachment diagram from a previous posting doesn't list the value- any help would be appreciated. Thank you, Michael
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Switch just pulls in the relay so NO real current draw thru the switch. You'll want a 30-40 amp relay.
Thank you Wolfgang, I did buy a 30 amp relay that's not a bosch but does have the same pin layout. Need to pick up the proper gauge wires that Gordon nicely described in the 2/11/14 posting "Wiring Driving Lights". Then start the wire routing process having the 20 amp fuse close to the battery source.
I am not sure about the diff with 12v vs 120v circuits, but 20 amps at 120v is 12 ga, and 15 amps at 120v is 14ga. amps are amps, and the power dissipated in a wire is a function of the current (squared) and the wire resistance -- fatter wire has lower resistance. That said, aside from the starter motor wire, I have not seen wire heavier than 12 ga in any car. If you were wiring a house circuit to carry 40 amps, you'd need 8 ga wire. Anyway, in my circuits in my car that are set up per your diagram, I used 12 ga twisted copper. Seems to work fine. My in-line fuse is 30 amps, I think.
