1984 gm truck horn fuses blowing, dead short, good relay

You can pull the fuse. The problem could be the horn contact in wheel or a short in wiring or horn relay

both dead that it?
fuses good?
one right and one left front. under bumper look see find em, both grounds good.
horn fuse F21 blow,
the dead horn pair the horn relay must cluck beeped. (2 man tests)
or bad clock spring in steering wheel (watch out for air bags, defeat them first)
bad horn button.or relay or clock spring to the button.


HORN
REMOVAL
(1) Disconnect and isolate the battery negative
cable.
(2) Raise and support the vehicle.
(3) Remove the front underbody splash shield
bingo

If it's blowing fuses, you probably have damaged wiring to the horn, not a bad relay (relays generally fail open rather than with a short to ground). Find the horns (GM usually uses two horns to play a chord), and inspect the wiring to them. Look for a bent terminal shorting to ground, or some spot on the wire where the insulation has been cut or worn by contact with metal. In particular, if the car has been in an accident, check the areas where there was body damage (if the horn relay was bent up by an accident, that may be an exception to the general case that relays themselves don't usually blow fuses.

the fuse blows because somewhere after the fuse , the wire is dead shorting out to ground
check / replace any horn relays

use a multimeter set on ohms resistance and that will tell you that it is shorting out as it will register as a circuit

my guess, its a dead horn? both dead?
no actual question asked????????
the fuse is blow? in fuse box, eng. bay box.?
if no power to horn, (voltmeter)
we check power in and out of relay if there is one.
then at the horn button wire, (air bags can kill any mech. defeat them
first if heck bent to fiddly steering column parts in any why)
all this info is convered in in the FSM, get one. or login to alldata dot come. and read it.
here, ill look at yours. now.... a fast look.
ok 2 horns, hi/lo, and 1 relay in the under hood fuse box.
it should be labeled in the box, HORN
the relay can not work if the fuse is blown
or the horn enable line is dead. button.
the button grounds (0v) the relay via wire color lt.green-blu pin a11 on relay. if the a11 is at 12v the fuse is good.
if you push the horn button this A11 goes from 12v to 0v, and the relay energizes (click) and the horns both blow.
if no power makes it to the horns, the relay is bad no 12v
if by chance the relay output to horns go to 12v, then the horns are both dead.

disconnect the horn or horns, operate the horn and see if the fuse still blows. if the fuse still blows then there is most likely a short in the wiring. relays rarely cause shorts. if the fuse doesnt blow with the horn disconnected, reconnect the horn and operate the horn again, if the fuse blows you have a shorted horn.

If you can't find the fuse in the fuse box, try looking in the breaker/ relay box. It is usually a 30 amp, big fuse, for the horn, and there shouldn't be anything with it, but you never know. The breaker box is near the battery or in the engine comp. I don't know exactly where they stuck yours, but most cars are close. Hope this helps.

horn may be shorted internally. Try pulling the connector off the horn, put in a fresh fuse, see if it blows.

If it still blows, you have a short in the wiring or the relay. If there is no obvious short in the wiring, change the relay.

If the fuse doesn't blow with the horn disconnected, replace the horn.

could be you might check it out. many items take the same relay so you might try exchanging it with another one with the same numbers. If that isn't it you may have a short in the horn itself.

You may have some short circuits in your wiring, a bad horn relay or horn unit, and/or a bad wiper motor. Hard to tell without actually looking at it.
Try this:
Disconnect the horn, and try another fuse. Does it blow? If not, the horn is shorted, and needs replaced. If it blows, remove the horn relay & try another fuse. Same with the wiper motor, unplug it and try another fuse. If it does not blow, you need a wiper motor.