Does anyone know what the ohms are supposed to be on transfer case sensors? would like to test before buying,also the relay switches as well in the dash what they should read ? I've been trying to locate the transmission sensor but to no avail ( I must be blind) is it on this truck? already tested sensor on rear diff. thanks to info here thats fine 4x4 lights flashing got codes P1837 (transfer case sensor ) and C1107 this is on a 1999 navigator 4x4 5.4 any insite on this would be appreciated ,It feels like its 4wd until I get to 30mph then 4x4 light starts flashing I did just have a wheel bearing replaced on front drivers side but flashing was there before that and odometer is flashing but I think I seen the fix for that I have not done the odometer thing yet Thanks (This site has tons of info so glad I found it !