So my latest project involves trying to repair a GE 8G1022 Bonus line ballast that will only light one lamp. I did some testing with a multimeter and found a ~60Ω short between one of the red wires and the yellow wires. So i cracked the ballast open and dug out the capacitor (a GE three-terminal 3.8uf and .05uf 320V capacitor) and tested it and it was basically shorted.

Now since the capacitor is dead, i'm not sure which side of the leads to hook the replacement caps up to.

According to the date code, this ballast was made in Feb 1977, so this capacitor is likely a PCB type.

From the capacitor side :

When you disconnect it you might be able to measure the shorted "main" capacitor between 2 of the terminals. Then you know it goes to them

Odds are the 0.05uF capacitor might be intact. You will be able to measure it in 2 positions - By measuring it directly, or by measuring it in series with the bad "main" capacitor (which you allready know the terminals of). To find out, apply some HF signal and see in what combination you get a voltage divider



From the ballast side :

When you disconnect the capacitor measure resistance from the capacitor wires to outside wires of the ballast, then its structure can be redrawn and capacitor connection determined



Most likely it would work with just the main capacitor, even if you leave the 0.05uF disconnected. It might have harder starts tho if that capacitor is somehow related to lamp starting. If you take a capacitor for double the rated voltage, it might happen to work in both possible positions anyway

If only one lamp lit then the small capacitor is shorted.  I’ve seen a schematic here before but I can’t find it now.