Riddle me this... why is one output low and noisy?

[soundsci]

The right side of my 73 suitcase is really low in volume and has a wierd wishing noise. My set up consists of the 73 suitcase top - connected to a custom speakeasy pre...it is an older 4 pin type connector. I have checked the cable and pre...both are ok....I have also checked the accsesory jacks...both are ok - althought one shorts out the other (ie you cant plug in two cables at once)- i dont even know what these jacks are for, but they buth produce sound...so the harp connections are intact and working...yes/no? i dont know.
pls help. Thanks