98 Chevy 1500 recently started flashing the high beams when the horn is pressed instead of sounding the horns. Fuse is good, and relay clicks when horn pressed. When relay is removed nothing happens.

If I remember correctly, your horn relay is powered off of the 20amp fuse for the park lamps.

Something that fuse powers is shorted to ground . Need to look at wiring diagrams , service repair manual , power distribution diagrams , disconnect everything it powers - one circuit at a time till fuse doesn't blow any more . Then find the short , videos on youtube showing how . EGN A ???? IGN A fuse . ENG 1 or 2
Underhood Fuse-Relay Center Fuse/Circuit Breaker
Rating
Description
ABS Fuse M4-N4
60A
Electronic Brake Control Module
A/C Fuse K11-L12
10A
A/C Compressor Clutch Relay
AUX A Fuse P7-R7
30A
Upfitter Provisions
AUX B Fuse P8-R8
30A
Upfitter Provisions
BATT Fuse M7-N7
50A
Instrument Panel Fuse Block
BLOWER Fuse M3-N3
60A
Blower Motor, IP Fuse Block
ECM-B Fuse F11-G12
20A
Fuel Pump Relay, VCM, PCM, Fuel Pump and Engine Oil Pressure Gauge Sensor
ECM-1 Fuse H7-J8
20A
Ignition Control Module, Ignition Coil, Camshaft Position Sensor, VCM, Fuel Injectors, Crankshaft Position Sensor
ENG-I Fuse L8-K7
20A
Heated Oxygen Sensors, Mass Air Flow Sensor, Exhaust Gas Recirculation Valve Solenoid, Evaporative Emission Cannister Purge Valve, VCM, Secondary Air Injection Relay, WATER IN FUEL Indicator Sensor, Fuel Heater, Glowplug Relay, Wastegate Solenoid, Crankshaft Position Sensor
HORN Fuse H11-J12
20A
Horn Relay, Underhood Lamp(s)
IGN Fuse F5-G6 (Diesel Only)
20A
PCM, Fuel Solenoid Driver, Engine Shutoff Solenoid
IGN-A Fuse M6-N6
40A
Starter Relay, Ignition Switch
IGN-B Fuse M5-N5
50A
Ignition Switch
IGN-E Fuse F7-G8
10A
A/C Compressor Clutch Relay
LIGHTING Fuse M8-N8
40A
Instrument Panel Fuse Block, Headlamp Switch
LH-HDLP Fuse F1-G2 (Export Only)
10A
Left Hand Low Beam Headlamp
LH-HIBM Fuse F3-G4 (Export Only)
10A
Left Hand High Beam Headlamp
RH-HDLP Fuse H1-J2 (Export Only)
10A
Right Hand Low Beam Headlamp
RH-HIBM Fuse H3-J4
10A
Right Hand High Beam Headlamp
RR BLOWER Fuse K5-L6
30A
Auxiliary Blower Motor Relays
ABS Relay (Expot Only)
--
ABS Warning Indicator Lamp
A/C Relay
--
A/C Compressor Clutch Coil
A. I. R. Relay
--
Air Ijection Reaction Pump Clutch Coil
Fuel Pump Relay
--
Fuel Pump
Horn Relay
--
Horns
Starter Relay
--
Starter Solenoid

I looked at info for a Silverado 1500. Use a test light to check for voltage at horn fuse in under hood fuse box. According to this diagram, the horn relay has to be energized. Have a helper hit the horn switch when you check voltage at horn fuse. If hot, have to check wiring circuit to horn. In the diagram, dark green wire is voltage and black wire is ground. You could actually use jumper wires from battery for voltage and ground to horn, for testing.

You have all the informations to find your problem. jump a wire on connector X4 G1 tan wire to ground and check X1 E5 with a test light or multimeter to see if there is a output, you should have 12 volts. If you dont have any voltage the horn relay is defective. I check in the shop manual and the relay come with the underhood fuse block.

If the bulbs flash when you unlock the vehicle, then they are likely not the issue. My guess is the relay contacts are dirty. Just because a relay clicks, it doesn't mean that it is passing current through the contacts. Try and swap the relay with another of the exact same part number. There's usually another available...ie the horn relay, fog lamp etc..

The horn relay is in the fuse/relay box under the hood. so the fuse is HOT on both sides? you should hear the horn relay click when pressing on the horn switch. there may be other relays in that fuse box to swap with and see if the horns work, if the relay clicks, its "usually" good, but the contacts may be bad. if the relay clicks, check for power at the horn. DARK GREEN wire, if it has power , then check the black wire, thats the ground. If it has power and ground, but does not work, the horn is bad.

Check in your owner's manual for the location of the horn relay. It will usually look like a small metal or plastic box that plugs into either the main fuse box or the high amp fuse box under the hood. If your horn fuse is good then most likely the horn relay needs replaced.

The click you here is the horn relay, You need to find the horns and check for power at the wire connectors. But you probably have a bad low and now a bad high not horn. since the relay clicks your fuse is good so that eliminates the fuse.

Hello! In the under-hood junction box is a 15A fuse labeled "Horn Fuse"...Also in that box is the Horn Relay...If the fuse doesn't solve the problem listen for the relay clicking while someone presses the horn button...If the relay is not pulling I would suggest changing the relay...Guru...Saailer

I’m happy to help further over the phone at https://www.6ya.com/expert/david_6df67de3b14de867

horn is under the hood. usually right against the grill or mounted on fender well. fuses for horn can be under the dash, or in fuse panel under the hood.