What is the amp capability difference between the rear defrost switch and the deck lamp switch? I believe the deck lamp switch has 2 wires, while the rear defrost switch has 4 wires. Im trying to repurpose these switches for extra lights and aux stuff and wanting the era-correct switches (which is why im usibg tgese rather than buying new switches). Any info you have would be much appreciated

 

There is probably no difference in the switches current capacity. The additional wires for one probably go to a pilot indicator bulb, or something similar. The deck lamp might be directly wired because the current it uses is small, while the defroster is likely to go through a relay.

It is always wise to use relay switching when the current is more than a couple amps.