I tested today my CGE and my Universal ballast. Both are half-dead (only one lamp starts up). So I wired a temporary fixture above my workshop with my Universal one. I plugged the first lampholder on the proper circuit (the red wires) and the second one on the yellow wires. When it starts up, this old ballast makes a soft buzzing (which I absolutely LOVE!  ) and it seems normal, but will the ballast overheat with this wiring configuration or will it break the lamp?

Can you be more specific....is it magnetic rapid start or electronic? Best thing is to monitor ballast and if it gets unusually hot or has bad oder or makes any other noises....discontinue immediately! If lamp seems normal brightness, and the electrode ends look normal, I guess lamp will be fine.

It's a magnetic rapid start ballast. And yeah all seems normal. The ballast is slightly warm after about 15 - 20 min. of operation, normal brightness and I don't really worry about the buzzing...

It's a magnetic rapid start ballast. And yeah all seems normal. The ballast is slightly warm after about 15 - 20 min. of operation, normal brightness and I don't really worry about the buzzing...

Slightly warm is fine, too hot to touch is a warning to turn it off I've had that happen to me before with a GE bonus line ballast, it got too hot to touch AND zapped me!! As a result, It got tossed across the room! It smelled bad too, what had happened was the cap went bad and leaked PCBs all over the inside of the ballast! that was a mess

Just don't leave it unattended! A few years ago, I had an old GE rapid start ballast go bad in one of my garage fixtures. I left for a couple of hours and forgot to turn the lights off. When I got back, the garage was full of smoke and the ballast was leaking black PCB tar all over the floor and in my tool box! This ballast was old and didn't have a thermal switch.

Yeah Rudy, I remember pictures of your fixture that had the bad ballast with leaking tar.......I was a new member that time....:-)

Fortunately, my Universal ballast has a thermal switch

Fortunately, my Universal ballast has a thermal switch

In this case, mine didn't!

I have had a garage fire because of a old ballast that had no therm switch!

Oh...  Not cool.... Recently I leaved the ballast with 1 lamp for a while and the thermal protection blew up (I though this first). After a 1h cooling down, I see that the thermal protection is auto-reset! The good quality of the past...