Are they suits of armor or or are they electrical conductors?

European knights wore a variety of armor that were all made of steel and/or iron, which are decent conductors of electricity.

Contact resistance would vary greatly depending on armor design - the more surface area that is in direct contact the lower the contact resistance.

Mail armor, for example, has a large number of rings in direct contact with each other. Each contact point is quite small, and will have a fair amount of resistance, but the sheer number of them in what is effectively a massively parallel circuit will probably result in a decent amount of conductivity.

Most plate armors have a small number of joints with (relatively) large areas of metal in contact and so would probably be a better conductor than Mail armor.

The knight inside the armor probably wouldn’t be in direct skin contact with any of the metal parts as there would be cloth padding between them.

This might conceivably make some forms of armor into fairly respectable Faraday Cages, protecting the wearer from electrical energies - albeit at the cost of quite possibly spot welding all the joints together. The overall heat generated in the process might well be significant too, depending on how much electrical power is going through the armor.