On my 2003 ford 350 power stroke diesel 4wd i got stock and i set my 4wd on and i got out with no problems but when i turn my electrical 4wd switch from inside of my truck it did not change the transsmition from 4wd low to 2wd i bought the electrical swith and tested the electrical motor under the truck and it is working , the question is if between the electrical switch inside the truck and the electrical motor under the truck exists some relay or fuse, i will appreciate if somebody help me on this

https://www.askmehelpdesk.com/cars-trucks/no-posting-your-question-more-than-once-482057.html

Begin by testing all under hood and under dash fuses with a test light or multimeter:

https://www.askmehelpdesk.com/cars-trucks/faq-how-troubleshoot-repair-maintain-hondas-selected-other-vehicles-46563-3.html#post252145

2003 ford 350power stroke diesel 4wd problems

I got on my 4wd low and I can not set it back, I bought the electrical switch already and tested te electrical motor under the truck and it is wirking ,I don't know what's going on

You will need to get a shop manual, perform the indicated tests, and just tear into it if needed. Sorry I can't be of more help.