Join Date: Apr 2006
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I'd recommend most strongly against using relays. The idea is good, but consider that each relay means four wires, four junctions, four more failure points, actually six more failure points if you count the relay coil and contacts as well. Or, more failure points since each relay coil needs to be FUSED as well! With separate fuses for each, unless you can afford to lose them all at once.
And it gets worse than that:
I was using a relay very much the same as the one in the picture (a Bosch 30Amp automotive relay) as a horn relay in my car. Worked fine for years, well potted, no reason for any problem. Except, my horn wasn't working. Tore my hair out for two days troubleshooting everything including the relay and everything tested fine--but the horn didn't work.
It turns out those relays are now made by molding the relay housing AROUND the qd plugs that stick out of their base. If the plastic lets go of the metal, you can wind up with the spade plug moving when you connect (or disconnect) a wire to it, breaking the internal contact in the relay. So, you take it all apart and test it, it tests 100% good. You plug the wire back in--and the contact is broken (by literally a millimeter or less) and the damned thing doesn't work.
Do you want six failure points in each circuit? I wouldn't. I'd rather just buy some nice new heavy-gauge tinned wire and extend the wire runs to the new panel. Or, keep the switches below--because no matter how "waterproof" they are, longer wire runs and switches that are above deck are going to be less reliable.