I have a 2000 Chey Blazer LS and a two weeks ago the horn stopped working. Every time I pressed it, the turn signal lights on the dash lit up. Also, when I use the turn signals, front signals all flash. Back turn signals seem to be fine. They all hyper flash.
This is a link to someone who had the same exact issue. . I tried the following
1. Replaced multifunction switch
2. Checked all fuses and relays (I hear the horn relay click)
3. Replaced all front turn signal bulbs (not using LED's)
4. Replaced the low/high horns. (Old ones were severe rusted)
5. Cleaned the two grounds on either side of the radiator (maybe they should be replaced or other grounds are causing this issue)

Mechanic suggested replacing the multifunction switch and that did not work. Any help would be appreciated.
Thank you

 

This is probably the rare case where you actually have a bad ground. The wiring diagram is complicating the diagnosis because it does not show the grounding point for the horn switch (also rare), only that the low side of the switch is grounded. I would start with locating G201 which is on the right side of the dash. Then check the two grounds at the left and right radiator supports. Then look at any ground points under the left side of the dash.

There is a splice in the ground wire on its way to G201 which is also a possibility but lets hold off on that for now since it may be hard to get to.

George

 

Thank you for the input George. I will check all these.

 

Just wanted to provide and update. Found this rusted out ground. Two grounds connected that rusted out. Located under the battery tray near the frame. Hopefully after repairing this, my issues will be resolved. Thanks for all the help

 

Good find, that should straighten out a few things.

George

 

Glad to see this resolved

 

"Glad to see this resolved"

Not resolved yet.

George