I have a 1999 Ranger 2.5l 5 speed 2wd, i've been having problems with my dome lights and "door ajar" light staying on at random times. From what i can tell the door switches must be in the latch in the door. Right now i just pulled the fuse out but that fuse also controls the GEM module...what is the GEM modue and is it hurting anything to have it unhooked, everything seems to be working fine.

 

Put the fuse back in , and get a can of WD-40 or something to the same, and spray your door latches liberally, so as to get in the latch itself(can be done from the outside), and your dome light problem should be solved.. This is a common problem with Ranger- and the GEM is a multifuctional creature, and it helps the computer maintain certain functions, and also puts the computer to "sleep" after a certain period of time, and so that there is no battery drain..Maybe someone on this forum can give a better explanation than I.......

 

The GEM is actually powered by several different circuits, so a lot depends on which fuse you pulled.

Regarding the overall function of the GEM, check out: https://www.ford-trucks.com/forums/s...45&postcount=9