First time on this site, so bare with me. Just got dash back in after blower motor resistor melt down and caught my truck on fire. But now I have NO power to either side of fuses( under dash) 5, 6, 16, 18, 20, 21, 26, 27, & 28.
HELP ME, PLEASE.
1997 F150 Step Side 4.6L

 

Yeah, we're psychic and we know what truck is being discussed...

 

what is the key position when you are testing the fuses ?

some of these you make note of are hot in run position only and fed from the engine compartment fuse panel.
#20 & #21 I see straight away both are 50A fuses & hot all the time that feed the ignition switch and then in the run position to 5& 6 at least, I stopped after I stopped after I saw the common theme to them, being run position fuses.

 

Like I said, Bare with me, cuz' I'm new to this. Yes, they were all in the run position, exactly the truck was running. they had NO power on either side of the fuse. I even took them out and checked to see if any power was there and not making a good connection, put still no power.And all the fuses under hood was hot.

 

If are you sure the 50A fuses listed above were good on both sides, and the fuses it feeds in the cab of the truck are dead on both sides with the key in the run position, either the wire from the engine compartment fuse panel to the ignition switch or the ignition switch to the cab fuse panel are damaged.

Time to go looking to find out which ones are damaged.

Engine Compartment fuse 20 to the ign switch is Light green w/ pink stripe & #21 is Yellow. These are from a 50A fuse, so it is going to be a large gauge wire.

The ign switch to cab fuse panel for fuses 5 & 6 is Red w/ black stripe wire as an example.
Start with cab fuses # 5 & #6 before going on to the others ( 5 & 6 are fed by engine compartment fuse #21 )

 

Thanks for your suggests, but I finally figured it out. The tach needle was stuck and wouldn't rotate, causing the circuit breaker to snap open. Fixed the stuck needle, now everything works fine.