Your tack on a 1995 Nissan pick-up started going up and down now it has stopping doing anything Where do you need to start find the problem?

1. Inspect the wiring. Start by checking for any loose or damaged wires. Look for any signs of corrosion or fraying. Any damaged or loose wires should be repaired or replaced.

2. Check the fluid level. The power steering fluid reservoir should be checked and filled if necessary. Low power steering fluid levels can cause the pump to cavitate and make noise.

3. Inspect the power steering pump. The power steering pump is responsible for providing the hydraulic pressure that moves the steering rack. Check for any leaks or damage to the pump. If the pump is damaged, it will need to be replaced.

4. Check the steering rack. The steering rack is responsible for turning the wheels. Check for any leaks or damage to the steering rack. If the steering rack is damaged, it will need to be replaced.

5. Inspect the tie rods and ball joints. The tie rods and ball joints connect the steering rack to the wheels. Check for any play or damage to the tie rods or ball joints. If any are damaged, they will need to be replaced.

If you have checked all of these components and the problem still exists, you may need to take your vehicle to a qualified mechanic for further diagnosis and repair.