Question about an 02 4x4 PowerStroke with electric control for 4 wheel drive lock and low lock.It does not allways want to go in and out of low lock,I mainly us it to back my box trailer up my driveway!Any Ideas?

 

Do you switch the transmission into nutral, step on the brake, and wait for it to switch? If you have an auto tranny, it will not shift into low without the gear in neutral and the brake pushed.

You also don't normally need low for backing a trailer 4H is usually more than fine.

 

What is this low lock you speek of. I have not known a t-case to have a low lock since the 203.
The above procedure should work.
Now as far as backing up large trailers, many SD owners will upgrade the stock ESOF hubs, and install manual locking hubs. This permits the use of low range without locking in the front end. You can achieve 2wd low range with this method. Often times the lower range helps when traction conditions do not require 4wd.

 

To continue what ed said, it will also give you the gearing you need to push back that trailer up a hill or whatever else you may encounter.

 

I can get my SD into low range w/o using the brake, but you HAVE to be in nuetral.

I use 2 low in the '79 to back up the camper all of the time, barely have to use the gas with the extra gearing.