[snorander]

Ok So my check engine light came on & it was the Air pump. Picked up a used one tested it on my bench, worked great. So I installed it, cleared the error code and was happy. A week later my light came back on, same thing air pump. So I put 12v on the pump and it works fine. Light bulb goes off in my head, I never checked the maxi fuse. So sure enough the 30 amp fuse is blown. No worries I have one & put it in. Fired the truck up and don't hear/feel the pump running. So I check the fuse it's still good, check the pump it still works when I put 12V on it. SO my question is: is the secondary air pump supposed to run all the time or only run when the engine is cold? As my car was hot when I was testing it.

Thanks,

Steve