5 or 4 wire relay?

Can I use a 5 wire relay off my ignition for remote turn on leads to my accessories? if so where do I hook [#87a] up to? (middle wire in relay) or should I use a 4 wire relay instead?

In most instances you can substitute a 5 terminal relay where a four terminal relay was utilized. However, It the 4 terminal relay utilized a prewired plug, a 5 terminal relay with the extra terminal 87a may not fit if the prewired plug only had four plug holes.  If you are substituting a 5 terminal relay for a 4 terminal relay, terminal 87a would not be wired to anything.

You didn't say what type of remote accessories you are trying to turn on, but if you are trying to operate anything with a reversible motor, like power windows or power trunk, then you would need the 5 terminal relays.