How did wires go bad?

The BCM test was the fob. Now we know the fault is between the BCM and the horn itself.

Have you tested the horn? Either continuity or applying 12V to it?

From post #2
" Note that the BCM is only in the circuit for alarms, the switch can blow the horn without the BCM."

 

So when I had no head lights the relay would still click to switch the driving lights off, but no high beams.
The high beam indicator would come on on the dash with no high beams.
This car has had electrical issues since my Uncle owned it.
The BCM actually lost power and a shop ran a power lead to it through the fire wall directly to the BCM and then things worked and randomly things like high beams stopped, rear cigarette lighter, and power mirrors.
Didn't bother him as he was a day driver not needing high beams and we all know how to manually move mirrors.
What happen to cause the loss of power to the BCM?
No idea, but I am sure something got hot in the wiring and caused these things to stop working.
My repair for the high beams was a new wire from the BCM to the fire wall and high beams worked.
I can test the horn itself today and the switch to test the functioning of them.

 

Somebody has messed with the wires. Running a hot wire to the BCM is dangerous.

Ran a wire from the BCM to where to make the high beams work? If the relay was clicking the BCM was connected to it.

Now you have a bunch of amateur wiring that might be causing other problems.

Most likely a connector on the bottom of the Under hood fuse box or the BCM is not making good contact. The connectors have pins in them that can push out the back, making for intermittent problems; the "gremlins".

Does your car have fog lights? Factory or after market?

Are you one of the millions that think DRL is the same as low beam headlights?

The high beam indicator is triggered by serial data from the BCM, that means the BCM is sending a signal. If it only flashed on then the DRL was on not the head lights.

 

From my post in 2015.

Relays were good.
Fuse block was good.
MFS good.
BCM good.
Issue was the TAN AND WHITE wire leading from the BCM to the fuse block.
In the center counsel is your air bag module.
With mine came some duct tape.
Did some resistance testing and found a section of wire from the bcm past that point to be an open circuit.
New wire in and high beams work as they should.
Your main harness for your car comes in the firewall and down the left side by your feet.
It meets the floor where the plastic trim meets the carpet.
Makes a bend in front of the drivers seat.
then bends up to the center counsel by your cup holder (also where your air bag module is located).
it then bends again toward the front of the car to the BCM.
The reason I filled that in is for someone that may have a similar issue.
The harness contains 2 for sure TAN AND WHITE wires.
The high beam one is the smaller of the two wires.
If I remember correctly on the BCM the wire is located in socket 42.

https://www.chevyhhr.net/forums/prob...s-53384/page4/

 

The tan and white wire triggers the relay. You said the relay was clicking. Which is correct?

Somebody messed with the wiring in the console near the airbag module?

 

The horn relay is not clicking.
So I am curious what wires to check for an open loop between steering column to BCM, BCM to fuse block, fuse block to horn.
I believe that is the sequence I need to check out.
Wouldn't that be agreed?
In the previous post I posted was from the last wiring issue I had on the car and my findings.

I think that opening up the duct tape wiring may open a can of worms which is why I left it alone.

I am going to eat lunch quick and then test the switch and see what we get, but based on what has been suggested it maybe from the BCM to the fuse block.

 

I took pictures to show what i have going on. It was as i suspected. As soon as i jiggled the wires and twisted then manipulated them the horn started to work. My guess is there is a little broken spot in the wiring and if i need to i will cut it and repair it, but for now it will get me by until summer when the weather gets better to fix it. The wires i messed with and horn started to work.
My high beam repair going to fire wall.
High beam repair at bcm.
My bcm and the power repair.

 

The tan wires in the lower left corner are what I believe are the Horn wires.
Maybe someone could give some better locating help so if someone in the future has a wiring problem they could test better.

Am I really the only one that has electrical issues at some point in the harness here?

I guess the duct tape may not be the issue, but unmolested wiring shouldn't just create breaks like that should it?
Especially coming down the door by the hood release.

Guess I just need to give the old lady's strings a rub every once in a while.

 

I don't see any duct tape.

Fwiw. Taking a wire and adding a different color to it (your black wire, white wire in photo ) is a bad way to do wire repairs.

 

Duct tape involves taking the console apart by the air bag module which is about under the cup holders.

You are right about mix matching wire colors especially black to a power lead, but I don't have an abundance of wiring laying around so I will make an effort to add some that way it makes it better for the next guy if there ever is one on this car which I am guessing will not be.

Thanks for the help guys.