I have a Tappan dishwasher that is approx. 20 yrs old. I don’t know where to look for the model number. I am having trouble with the dtergent dispenser. I can’t get it to stay closed. It is open all the time. The dishwasher runs fine otherwise. All cycles work properly. I just have to add detergent during the wash. Any help would be greatly appreciated! 
Daryl
Most of the model numbers are on the tub frame where the door rests.
Nat
OK! It is a Tappan Model 61 1134, Serial # 65 292994. Any ideas?!?!