J30 Power Steering Problem

My wife's 1994 J30 (96k miles) has recently developed a problem with the power steering. On an intermittent and unpredictable basis, the power steering develops a "heavy" feel, like there is not enough power assist. It seems to come and go with no rhyme or reason. It does not seem related to temperature, how long it has been sitting, etc.

There are no obvious problems in terms of fluid level, fluid leaks, pump noise, etc.

Any ideas on how to diagnose and solve would be appreciated, as well as similar problems and experiences.

Check the Power steering speed connector, it may be broken or loose connect which can give a false info about speed and reduce the power assist.

Check the Speedometer Sensor Harness & Connector.

you may wanna look under the car and check to see if ur rack and pinion is leaking... i hear the winter cold really screws that up a lot.

check the steering solenoid first, you can do this by unpluggin the connector (its a foot long shielded wire starting from driver side where the solenoid is to passanger side where plug is) run 2 wires from pos and neg of battery and direct connect them to the connecter that runs directly to the solenoid. it wont matter what wire on the connector is pos or neg cause it just gos in and back out of the solenoid. if you hear a clicking noise coming from the solenoid then its fine if not then thats your problem and have it replaced. the only other thing i can tell you is that it could be the vehicle speed sensor which is located in the dash. so let me know how everything gos. ill try to further help if i can.