Ground short causing horn to go off

[KCk51974]

Ok, 1970 K5 blazer. I have replaced the horn relay and turn signal switch. When I connect the turn signal switch, the horn blares and stays on.

The wire to the horn appeaes normal, and the horn relay is obviously getting power. There are no breaks in the black wire between the horn relay and the connector to the turn signal switch.

The PO appears to have soldered the red wire off of the horn relay to the red wire going to the ignition switch and the red wire going to the headlight fuse. Could this be the cause of the ground short? I would not think so because the horn only sounds when I connect the "half moon" turn signal switch coming off of the steering column. That suggsest to me the short is somewhere after the turn signal switch connection, but i can find. Any guidance would be appreciated!

David

 

[6872xtc]

Did it have this problem before replacement of the turn signal switch?
I would be checking to see if the new one had a couple of wires installed in the wrong place. Otherwise, there would have to be the horn button stuck, or assembled incorrectly, or the horn wire is shorted in the column.

 

[KCk51974]

Yes, it did. I thought it was a bad relay, so I replaced that. I had to redo the wires On the turn signal switch a couple times, so I know they are in the correct spot. And horn will blare if I touch the wires even with the rest of the horn parts unattached. Very strange.

 

[Wes Harden]

Take the horn button apart then plug in the turn signal switch.

 

[KCk51974]

Did that. Horn Still sounds constantly.

 

[Wes Harden]

So is near switch, or the plug is miss wired.
The horn ground should be black wire and is normally on far end.
Should match a black wire in truck side of plug, but I won't bet on it.
Could be just under steering wheel.
Horn ring area.

 

[KCk51974]

I also isolated the black wire on the steering wheel side of the half moon switch. When I touch that wire to the black wire on the car side of the half moon switch the horn Activates.. Also, I accidentally touched the black wire on the car side of the switch with a screwdriver, and the horn sounded, but I guess that is not surprising?

 

[Wes Harden]

If the screw driver was grounded that's the way it works.
So everything on the truck side is good.
Problem is in the column. Might even be a bad new switch

 

[KCk51974]

Screw driver was in my hand, while I was sitting in the car. Assume that constitutes grounding the screwdriver?

 

[Wes Harden]

not really, I mean most people to much resistance for 12v dc. butt nakkid and all sweaty .... maybe screw drive contacted 2 terminals at same time.

 

[bp71k5]

Is this the stock steering wheel for the ‘70?

 

[KCk51974]

It looks likes it, but I am not sure. Also, the steering wheel is cracked right through the middle. Not sure if that is contributing to the short. Don’t see why it would.

 

[bp71k5]

It looks likes it, but I am not sure. Also, the steering wheel is cracked right through the middle. Not sure if that is contributing to the short. Don’t see why it would.

the horn contacts and spring are kinda flaky on the original so you might check the contact to see if that’s the problem