My galant's power steering only works at higher rpm

Low on power steering fluid or the pump is going bad.

you could have a problem with the connectors inside the plug,check thet first,those sensors are pretty tough,but sometimes they do go bad.

bad power steering belt.

sounds like the belt may be loose, if it is tight I would go with the power steering is going out. As when you have a higher rpm the steering improves. Hope this helps tim

check ur plug wires they might be mismatched ...joe

Rack n pinion is bad

If memory serves me correctly... the 05 deville is equipped with "Magnasteer" the electical connector at the rack and pinion is not a pressure sensor unless its on the line itself. The system operates by inducing voltage to magnets in the rack to make turning easier at lw speeds while adding resistance at higher speeds for added control and less drift. Check for any codes on your climate control by pushing "off and warmer" at the same time with the engine off, key on. Google the codes and see if any relate to the steering system and repost! I hope that helps!

no it is the power steering pump. the pump is worn so at low rpm or low speeds it is real tough to steer. but when the rpm is picked up the steering gets easier.

Also check belt tension but at high rpm speeds the belt would slip and squel real loud. so i would point the problem to the power steering pump.

hope this fixs ya!!!!!!!!!!!!!!!!!!!!!!

is the fluid circulating well , you could see it through the power steering fuel level after removing the rod , if not then you got proplems with the pump ,if the fluid is circulating the the rack and union pistons may have ruined