Hi, I'm new to the forum and I'm stumped. I have a 2001 Ford F-150 with a 5.4L. The engine is used and is a 1998 model. The other day I decided to change my spark plugs. I changed one and decided to tackle it another day due to time restrictions. I put the old plug back in the truck and attempted to start it. It was idling really rough (shaking the hood). It idles for about 5-10 seconds and blows the instrument cluster fuse. Any idea as to what is causing this? Thanks in advance.

 

Didn't pull my manual, but a quick Google search showed really nothing on the same fuse as the instrument cluster to do with engine function. However if you check your manual it will show you what is on that fuse.

As far as the engine make sure you got the COP completely seated, aswell as the plug correctly plugged in. Then make sure you didn't accidentally unplug a injector.