Hey guys I have a 1998 F1 50 has a V-8 engine 4.6 L so I was looking under my hood checking my fuses and found a small third fuse box under the hood it is at the very top right corner and is a single row of six fuses my. one of them was bad it was a 20 amp so I stuck a Nother 30 amp fuse just to see if that would fix any problems the truck began to idle very rough wondering what this fuse box is for thank you for your help

 

Here is what you have by owner manuals research for 97 and 98.
An early 98 or a late 97 titled in 98 with the 97 fuse system configuration.
A 98 owner manual does not show it but a 97 does for the small distribution box you have as shown in a 97 manual page 142.
If fuse position #2 it is for the trailer tow stop and turn signal supply..
Fuse 1 is for the computer.
Position 3 to 6 are not used according to the assignment list.
Do not leave a 30 amp in place.
If a 20 amp blows there is a circuit fault.
# 2 normally would have nothing to do with engine control.
If it does, either there is a harness short or the drain is putting a high load on the alternator.
Leaving a 30 amp fuse in place is inviting a fire and melted wiring.
Good luck.

 

Ok thanks for the information the late 97 thing makes sense since I can't match the vin with another 98 vin as for the 30 amp fuse I took it out and don't plan to get a trailer anytime soon.

As for the alternator drain that brings up another question so I have a few things hooked up to my battery like my radio, an inverter, and small off-road lights at times the off road lights flicker when the truck is idling with the radio on and the inverter off is this normal ??

 

Need more information, all of those things add current draw but they vary greatly by what type they are so it's hard to say whether it's normal or you have an issue somewhere. So, what type of offroad lights, how many, what type of inverter, is it powering anything at during the times it flickers, what type of radio, any additional amps, and how loud are you listening to it?

 

Music not very loud. No additional amps, it's a Sony CDx-gt330(xplod) The inverter is off but it is a 450 watt and the off road lights are small just 2 of them and 6 inches at most they are cheap Walmart lights.