Quite often I see fluorescent light ballasts that are leaking a black tar like substance. What couses this and should they be replaced ASAP?

Thanks.

John G

Overheating and age causes this.

So, would the "overheating" be a result of imprper wire connections?

So, would the "overheating" be a result of imprper wire connections?

Probably not since they are still working,

Magnetic ballasts tend to overheat with age, and often right after you replace lamps. Unfortuantely when the "tar" starts to leak out, often it allows line or output voltage circuits to short out. This can causing smoke and often become hot enough to ignite flammable surfaces the fixture may be mounted to, before it trips the breaker. It's best to replace the ballast ASAP, preferably with an electronic type. You'll save some energy, and the likelihood of the electronic ballast burning is negligible.