I had a set of those tabs before I replaced them with my new 280s. I really wanted indicators. I changed out one motor that went bad right after I bought the boat, so I'll give it a shot.
When you replaced the motor you made sure to get the slotted drive shaft back into place, right? Mine was trickey and wanted to stick to the motor, but I got it after struggling a bit. I'm guessing yours might have fell out causing your problem?
Here is the parts breakdown for the tabs, but it doesn't show what I'm talking about (its in the reservoir under the motor).