B190 Enthusiasts

My turn signal fuse is blowing and when I went to look it up I found out that the aux. battery relay is connected to this same fuse.

Looking under the hood at the relay (the cylindrical object/ solenoid mounted on the front side of the car near the aux. battery), there are two large terminals; one with a small yellowish wire on it and on the other side a heavy gauge black wire (no power on it) heading to another small square junction box and continuing on. The two small terminals are labeled; i & s, with a small purplish wire on the "s" terminal. The aux. battery has also been disconnected and I have no idea on which side of the relay the positive lead connects to.

Does anyone know how to test the auxiliary battery relay?

It just occurred to me that they're probably simple relays, which have four terminals.

One is ground, one is switched power, one is "input" power (source), and the fourth is "output" power (charging). Of course the hard part is figuring out which terminal is which.

I figure it out. Googled Ford battery relay and found out that it's just a dual battery separator. I haven't tested it yet but the + leads go on opposite sides and it appears would connect only when the ignition is on for charging the aux. battery. The heavy wire going away from it towards the small junction must be going to the electric panel, power converter or something of that sort to power the interior, and the aux. Battery + lead goes on that same side.