1997 F150XLT 4x4 EXT CAB 350,000K
just picked this truck up for cheap ran and drove
driving it home noticed it shifted hard and seemed fairly gutless
abs light is on in dash as well as airbag light
and door a jar light on even know doors closed .. (door sensor I know)

I got it home anyway then decided to see if the 4x4 worked
switched the switch to 4H click worked then to 4L then back to 2H didn't disengage from 4L

when I was messing around with it all I noticed also the interior light wasn't working took it for a drive rolled windows down as truck sat for about 1 year was a little dewy , came back parked was still messing around with fuses cause still no luck removing from 4L then noticed interior light started working and map lights etc , but the windows just stopped working, so I am thinking my 2 main problems with truck is the GEM and SPEED SENSOR on diff , when driving also speedo doesnt jump around and seems on , but tranny shifts hard up and down

also checked all fluids they were good , rear diff was low but got topped up , tranny fluid also okay but I am still scratching my head over the lights is it possible they were maybe damp? from truck sitting , then finally I heated it up and they started working ? had to pull fuse so interior light doesnt stay on over night untill I get a new door switch , also when I was messing with fuses I noticed the fog lights fuse was out so I put a new fuse in and the fog lights come on right away even with switch off , but when your turn switch for fogs on it shuts them off , could that be the switch is done or a relay issue??


hopefully you guys can shoot me in the right direction
want to save this truck cause body is in great shape as well as the frame ...

 

Starting to sound like a broken record here, but the first thing to do is change the trans fluid and filter. Drain the converter, too, there's a rubber plug in the bell that gives access to the plug in the converter.
As I have stated on many threads here, these trannys don't handle periods of inactivity well. They get stiff and don't shift right.

 

What sort of "period of inactivity"? I actually have just parked mine and was planning on putting it on project duty over the summer, so it's like maybe a couple times a month'ish drive time, the tranny will get cranky of that? If so, I'll just take it to work once a week lol



OP-- the moisture issue may be the windshield leaking, I've noticed several little trickle lines on mine, and of course I'm sure you know how well water and electricity work together... might be a good place to check to prevent future problems with what you've replaced already.
For the switch, if it's working opposite to how it's flipped (off/on backwards) I'd pull it out and check to see that the wires aren't simply flipped on the wrong connectors first.

 

Did you come to a full stop put your foot on the brake then shift in and out of 4lo?

 

Shifting the 4X4 switch requires the trans be in neutral and the brake pedal depressed, and the key on.