The FJ does indicate that this unit was manufactured in 1999. Most Kenmore dishwashers beginning with model number 665 will last about 15 years. Since the unit is older than 1/2 of the average useful life, it is not normally recommended to spend more than 1/2 of the price of a replacement model on a repair. If you have a service technician repair the dispenser, it will likely cost between $150 and $250 to fix this problem depending on the exact cause.
This failure is fairly minor. Most of the time it is caused by a failed dispenser assembly in most Kenmore dishwashers beginning with model number 665. On some models, you may be able to replace the dispenser assembly yourself. I provided a procedure for replacing the dispenser assembly on a common 665 Kenmore dishwasher in the image below. If your dispenser looks like this one, then you may be able to fix your problem by ordering a new dispenser assembly from the
website. Use your full model number to access the parts list diagram for your particular dishwasher.
Shut off the breaker
for the dishwasher and replace the dispenser using the procedure shown below. NOTE: Before ordering the part,
shut off the breaker
for the dishwasher and check the wire harness connections. If replacing the dispenser does not fix the problem, you could have a wiring failure or a failed control board (or timer) on the dishwasher.
If you need more help, resubmit your question with additional details and the full model number of your Kenmore dishwasher.