fuse #8 keeps blowing

I belive #8 fuse feeds your radio, outside mirros, speedometer and dome lights. Try to isolate the problem, first try replacing fuse with key in iff off position and doors closed, if fuse doesn't pop, open a door to turn ur dome lights on, this is probably where ur problem is, if it still pops, disconnect mirros and so on til you narrow the problem down

Does the fuse blow at soon as it is inserted with everything off? If so, check for a short within the fuse panel. If it doesn't blow, follow the procedure outlined by irondril.

You won’t believe this but I was having the same issue with my 1994 F150 5.0 4x4 and I did everything from pulling the dash out and tracing the whole dang wiring harness to buying a replacement gauge cluster and it still didn’t work. Kept blowing the number 8 fuse and the speedometer, power door locks, and dome lights wouldn’t work. I had a hard shift out of first into second and it never seemed to want to shift right. Check engine light stayed on and the code kept saying Limp Mode but it would get up to 80mph just seemed under powered. So, during round two of pulling everything electrical out and putting it back in after close inspection of wiring and connectors, i got frustrated and seen the old key less entry module under the dash and said to myself “I’ve tried everything else...” I unplugged it and stuck a 15 amp fuse and in number 8 and it didn’t pop! I turned the key on and the odometer lcd came on! I took it for a drive to check the speedo, which worked, and no more hard shift or feelings of being underpowered. It down shifted and up shift flawlessly and had a pep in its step that I hadn’t seen since I bought the truck! My door locks and my dome light still doesn’t work but that’s a small price to pay to have the major issues fixed. Who would have thought the keyless entry would do that...

There is a Ford TSB on certain year F150's and Broncos. The screws holding the dome light in are too long and if they touch the bare roof it shorts the fuse. Crazy but true. Wind pressure from highway speeds forcing the roof down and/or pressure from automatic car washes will cause this short.

My number 8 fuse In my 1994 Ford F-150 keeps blowing everytime I put a fuse in it wondering what’s causing it to do that