The tuner should have RCA audio outputs. You would connect those to any unused RCA input on the Pioneer. You might have to select an odd input -- VCR lets say, to get output from the tuner, but it will work.
If by "tuner" you mean a receiver then to get the tuner section to connect to the Pioneer receiver use the tape record outputs in the manner that kanewolf suggests. The only controls on the Fisher that would work would be the power switch and the input selector (or record selector if it has separate listen and record).
If by "tuner" you mean a receiver then to get the tuner section to connect to the Pioneer receiver use the tape record outputs in the manner that kanewolf suggests. The only controls on the Fisher that would work would be the power switch and the input selector (or record selector if it has separate listen and record).
I guess I took the OP's word and assumed it really was a component tuner....