I have a 2002 Ranger XLT 4.0L auto transmission 4x4 with 4x4 issues. Over the last few winters, I've had to boost/jump the battery a few times and I think it has impacted the 4x4 system (I read somewhere that this can fry the 4x4 control module). The truck doesn't come out of 4x4. The 4x4 switch doesn't seem to do anything, no 4x4 light shows up on the dash. I've replaced the 4x4 control module twice with used replacements, this fixed the problem each time (4x4 light on dash would come on, and the truck would shift from 2x4 to 4x4 fine when the switch is used) for a while but the problem reoccurs after boosting the truck in very cold weather. What could the issue be? 1. All the fuses appear to be fine. How many are there? Maybe I missed one. 2. Could it just be a faulty switch? Maybe a used one from the junk yard might be needed. When testing with a multimeter I don't get any voltage from the 4 connections on the switch nor from its connectors. 3. Could it be a connection in the 4x4 control module wiring? I saw a YouTube vid about this a while back but I can't find it now (grrrrrr...) 4. I'm wondering if it could be the transfer case shift motor. 5. Some people say I should check the wiring and grounds, where are all the grounds? I don't want to do the trial and error method anymore, where one just throws new parts at it, hoping it will fix the issue. Any troubleshooting tips to narrow it down to the problem?
