4x4 issues

[ashaeker]

Hey guys, new here but I've been searching the forums trying to figure out a problem and haven't found anything yet. I've got a 2004 EB expedition with just over 300K miles and I'm having trouble with the 4x4. I used the 4x4 multiple times this winter but then it just stopped working. Started out checking fuses, nothing. Checked the vacuum system and no leaks. Replaced the vacuum solenoid on the firewall, didn't change anything. I hooked a light up to the solenoid and it didn't seem to be getting any signal from the 4x4 switch. I actually bypassed the solenoid on the firewire while the 4x4 hasn't been working to make sure the hubs stay unengaged. After a lot of reading, I thought it was the transfer case motor, so I replaced that but still nothing. The 4hi and 4lo lights still come on when I start the car, and they actually were blinking for a couple of weeks. They would blink 3x then pause for a bit then 3x again, but they haven't done that in a few months. I recently had an intermittent ABS light and ran some codes to find out that I had a problem with my right rear sensor. I hoped that maybe this was the cause and changed the hub and sensor all in one and that got rid of all but one of the codes C1165 (right rear harness). I also recently lost the horn, and the cruise has been hit or miss along, as well as I get a battery light and check charging system on cool damp morning sometimes, but after going down the road a ways it goes away, and I won't see it again for days or weeks. After running codes again, I do have a B1676 as well as a U1900. B1676 has to do with the ABS control module. I'm not sure if these could all be part of one larger problem of if they are all separate problems on a high mile car. Up till the last year or so the car has been low maintenance and still runs down the road well. Could this all still be due to the right rear harness or possibly a weak battery or alternator? Thanks in advance for anyone that has any suggestions!