It's call Power Steering.
Could be steering rack is worn and needs replacement
Bad Battery. Bad Alternator. Lights left on by mistake. Something left running. Exc.
in steering cloum a silver plate wears out.
my 1999 did the same thing and I found out it was my transmission.
Check for codes... It maybe a bad coilpack. Or bad sparkplugs.
On a 1999 Ford Expedition : The fuse box is below and to the left of the steering wheel , by the brake pedal ( it has a cover on it ) Also , the Power Distribution Box ( which is " live " ) is located in the engine compartment near the brake fluid reservoir
A bad power steering pump, You need to either check the fluid level and make sure there is enough or have it replaced.
The code scanner is reading a P1450 on my frod expedition? what would be the problem
I didn't find any sensors or switches related to the power steering, so I'd think the pump was bad.
where is located ford expedition 1999 relays