TRYING TO LOCATE STARTER RELAY IN BATTERY JUNCTION BOX OF 1999 FORD EXPEDITION XLT?

Likely you have a blown "fusible link". These are located either near the battery + or the starter and can be difficult to locate.

horn relay (located in the battery junction box [BJB]).thanks

There isn't one , has a starter solenoid mounted on inside fender . http://www.carparts.com/details/Ford/Expedition/Standard/Starter_Solenoid/1999/SISS598T.html?TID=bngpla&origin=%7badtype%7d&gclid=CNCs3Pnm59ICFYyjNwodJcwBOQ&gclsrc=ds

Did you look under glove box right side????

It is in the battery junction box in the engine compartment ,

Check the CLEANLINESS of the Vehicles Cable CLAMP connections to the New battery, and if the battery has been stored for a long time,
those Terminal Posts will Oxidise slightly too, and may also require cleaning up.
If that does not have any effect, then go to the Main Accessory Power Relay and Interchange it, with one of similar function. This is identified by the relay # type in the Power Box,....and try again.
Any further difficulty, come back to me.
Regards, DT

There are 2 relays or solenoids as they called on a starter, one is on the inside of the fender under the hood, follow the positive battery cable, the other is on the starter, both do the same thing, later years only have the one solenoid on the starter.

on the firewall behind the battery