Hard low speed turns - 1998 GMC Sonoma

I would flush the steering box really well and re-fill with fresh fluid. If you can get to the lines, it is not too hard to do. There are some additives available for power steering fluid, but the use of them is debatable.

you can't, it has to be changed. older steering boxes would turn fairly easy without p/s, but it is not a manual steering box a will be really hard to turn at low speeds, and be hard to keep going straight on the road at high speeds,let alone corners!

run fault codes to find reason for the low engine rpm.. hard steering comes when the engine stops and there is nothing to turn the power steering pump.

low on power st. fluid

Depending on how hard or sharp you are turning, this could be the CV joints.

you might need a new power steering pump

this problem is evident in vehicles that have a strut suspension
at the top of the strut there is a plate that is the top plate for the suspension coil spring
above that plate in the rubber bush is a bearing
if that bearing has failed then the plate will not turn and when you turn the steering wheel the power steering is in effect winding up that coil spring
that makes low speed turning very heavy on the power steering system especially at low rpms
have the front suspension checked for that bearing failure ( both sides ) by an accredited suspension specialist shop
standing stationary and turning the wheel you may even hear a creaking or groaning noise as the spring is flexing on the strut
if you do not have a strut suspension , take it to a power steering specialist shop for a proper diagnosis

Do the blower speed settings still work, just weaker? Or is it just one low speed all the time? If you can still change the speeds then it's a weak blower motor. If its just one low speed all the time, (same speed for high and low blower speed settings) then you need a blower motor resistor.

Have you checked the power steering fluid? Do the belts squeel when you turn the steering wheel?
I know this might sound silly but are your air pressures in your tyres correct? Low air pressure will cause your steering to shake at speed and it will be hard to turn at low speed.
I hope this helps,
Scott.

sounds like you may have a bad front cv axle inspect it you may find that i'm right ,and no you can't disarm the all wheel drive . hope this helps you!