How would one translate Fuhr` den lockren Zieisighahn
It would be good if you could give the source where you found the words. It is a very old song from the 19th century, and the line you give is not complete, it includes typos and makes no sense alone.
Source: Wikisource, song 341 here: https://de.wikisource.org/wiki/Allgemeines_Deutsches_Kommersbuch:155
This is the text from which it is taken (old language, old spelling): 1. Bin ein fahrender Gesell, kenne keine Sorgen, labt mich heut ein Felsenquell, thut es Rheinwein morgen. Bin ein Ritter lobesan, reit auf Schusters Rappen, führ den lockren Zeisighahn und den Spruch im Wappen:
The relevant part of the sentence, in modern language, would be: "Ich führe den lockren Zeisighahn und den Spruch im Wappen."
The expression "im Wappen führen" means that the coat of arms (Wappen) of the speaker shows something; in this case the picture (of the Zeisighahn (male siskin)) and the words (that come in the following verse).
What is the source? Have you heard or read it? With "lockren" insteed of "lockeren" it looks like a poem.
ich/er/sie/es fuhr=I/he/she/it drove (but why the "`" behind?); den=the; lockren comes from locker=loose, slack;
The word Zieisighahn does not exist and it does not look like a German word (even not a neologism) due to the "-iei-". Google suggests "Ziegenhahn", which seems to be 1st. a surname 2nd. the name of a company for guns 3rd. due to 2nd a name for guns of this company. Ziege=goat; Hahn=cock, but in older German also a position/place(I can't find the right word) where something comes out. Even nowerday a water tap is called Wasserhahn in German. So a Ziegenhahn is a place where goats come out (I do not know how).