No brake lights
On my 1990 ford f150 xlt lariat I don't have
have any brake lights I just replaced the
brake switch and the wire going to it . Also
fuse number 1 stop / hazzard lamps; speed
control . I checked the fuse to see if that
would be the problem and it was blown so
I put the regular 15 amp fuse in and it blew
as soon as I put it in I am lost as what It
could be I fiquered it could be a short
somewhere has anybody had this problem
before I am lost as wat to do?
was it a 15amp fuse you took out in the first place?
like the first fuse the blew?
Yes you are looking for a short in that circuit. Not an easy job to find. Start inspecting the wiring for any obvious damage, any wire with its casing rubbed off or broken. You'd probably find it either in the back end around the tail lights or up front by the break pedal. A power line touching ground.
This is a common problem just fixed mine the other day. It is the light switch and it is a $16 part. Watch the YouTube on replacing it is easy to do. Just remember to push the button on the bottom of the light switch to remove the shaft the knob is on. There is a tan wire and I bet it has melted the connecting block. Mine had a burnt spot on the tan wire I cleaned it up and put electrical tape on it!
Since the fuse is blowing as soon as it is plugged in then suspect a dead short from the fuse panel to the various elements controlled by the fuse (brakes, speed control, and others). Disconnect all three from the electrical source and plug in a new fuse. If he blows right away begin checking at the fuse box forward for the cause. If it doesn't blow, reconnect each element until the fuse blows, then check accordingly.
Was the fuse blowing before you changed the brake light switch? You indicated you replaced a wire "going to it". Check that repair first for proper connection and possible short.
If it's doing it without turning on your lights or anything, it's the healight swith. Verify by unplugging it and see it still blows, if it doesn't, replace switch
Looking for a Used F-150 in your area?
CarGurus has 208,132 nationwide F-150 listings starting at $1,499.
Search Ford F-150 Questions
Ford F-150 Experts