shocking development

[John P.]

Hi, owner of a 1965 roadster- Had steering box replaced as well as other work, but steering column otherwise not deconstructed. Now I get a serious electric shock when pushing the horn button. Replaced button, looked below it-ok . Horn sounds but don't want to use it. Ha.

No doubt a grounding issue, but where? Is there a ground strap or connection to same missing? Not sure where to look. Thanks

[Michael W.]

Re: shocking development

The button and column needs a ground path for the horn to sound- presently you're it. The normal path is via the rag joint coupling that mates the steering box to the steering shaft. Try jumping it temporarily to see if that does the trick.

[John H.]

Re: shocking development

John -

The original rag joint had an internal copper strap joining the upper and lower flanges, to establish the ground path from the horn button to the frame (through the steering gear). If that strap has broken or corroded away, you are now the ground path.

[John P.]

Re: shocking development

Thanks for the input guys. On careful exam the ground strap appears to be there and in position. Any other ideas?

[Terry M.]

Re: shocking development

There isn't a chance they coated the steering box or frame so well that there is no ground path? I would think that would be hard to do, but stranger things have happened -- especially with powder coating.

Another chance is the ground wire in the steering column is broken/disconnected.

[John P.]

Re: shocking development

If I ran a ground from the button, down the column to the frame should that do it? Can I just connect to any ground wire on the back side of the cluster?

[Terry M.]

Re: shocking development

If I ran a ground from the button, down the column to the frame should that do it? Can I just connect to any ground wire on the back side of the cluster?

As a temporary measure there ought to be a ground at the parking brake that might be more accessible than the back of the cluster -- unless you have the IP apart. Please tell us if you do have your IP apart. I am not sure of the button construction on your Corvette -- your year is outside of my experience. I assUme the button is metal, since you are getting a shock. There may be a spark at the button when you connect the temporary ground. That may cause some cosmetic damage. That ought to be avoidable by connecting to the ground last.

FWIW: When we do this kind of "troubleshooting" we use a in-line fuse in the temporary jumper. Mose folks don't have this kind of jumper, but it can be easily made. In-line fuse holders are available at Radio Shack. Might be available at the big box auto stores, but I have never looked. I would start with 10 amps, but if that blows you might try 20 amps, but that is as far as I would go. Don't hold the temporary jumper in place too long.The problem is you don't know where this voltage is coming from (I know it might seem obvious, but assUming anything with electricity is very dangerous. If we knew where the voltage was coming from we would fix it right away, right?) and you don't want to burn up your wiring harness.

[Ronald L.]

Re: shocking development

John,
You have to fix this right - properly - or you risk burning up the car.

If you don't know how to diagnose electrical basic circuits with a multimeter, you need to get the car to someone that can.

First verify that you have zero resistance from one side of the rag joint to a spot on the frame. Is the resistance = 0?

[Ridge K.]

Re: shocking development

Agree with Ron. Fix it right. There's too much at stake to put it on a back burner.

In my 29 year former career in firefighting, the most common automobile fire cause I personally saw was electircal shorts .....on a hot battery.

#2 was likely someone priming the engine by pouring a little gasoline down the carburetor during engine start-up. (as in fresh overhaul). We've seen this done in youtube videos shared with us on the TDB. (hint, ...pour from a tiny container, not a gallon gas can or larger)

#3 was likely careless cigarette smoking

Here's a pic of a souvenir from a classic car fire I responded to in the 1980s. Burned to the frame.
The lump in the pic is the ignition switch pot-metal melted, and having poured itself out of the steel steering column. The brass objects are the remnants of the ignition keys, likewise melted.

Better safe than sorry!
Ridge

[Clem Z.]

Re: shocking development

As a temporary measure there ought to be a ground at the parking brake that might be more accessible than the back of the cluster -- unless you have the IP apart. Please tell us if you do have your IP apart. I am not sure of the button construction on your Corvette -- your year is outside of my experience. I assUme the button is metal, since you are getting a shock. There may be a spark at the button when you connect the temporary ground. That may cause some cosmetic damage. That ought to be avoidable by connecting to the ground last.

FWIW: When we do this kind of "troubleshooting" we use a in-line fuse in the temporary jumper. Mose folks don't have this kind of jumper, but it can be easily made. In-line fuse holders are available at Radio Shack. Might be available at the big box auto stores, but I have never looked. I would start with 10 amps, but if that blows you might try 20 amps, but that is as far as I would go. Don't hold the temporary jumper in place too long.The problem is you don't know where this voltage is coming from (I know it might seem obvious, but assUming anything with electricity is very dangerous. If we knew where the voltage was coming from we would fix it right away, right?) and you don't want to burn up your wiring harness.

the auto parts stores also have inline fuse holders

[Domenic T.]

Re: shocking development

Agree with Ron. Fix it right. There's too much at stake to put it on a back burner.

In my 29 year former career in firefighting, the most common automobile fire cause I personally saw was electircal shorts .....on a hot battery.

#2 was likely someone priming the engine by pouring a little gasoline down the carburetor during engine start-up. (as in fresh overhaul). We've seen this done in youtube videos shared with us on the TDB. (hint, ...pour from a tiny container, not a gallon gas can or larger)

#3 was likely careless cigarette smoking

Here's a pic of a souvenir from a classic car fire I responded to in the 1980s. Burned to the frame.

.

DOM
The lump in the pic is the ignition switch pot-metal melted, and having poured itself out of the steel steering column. The brass objects are the remnants of the ignition keys, likewise melted.

Better safe than sorry!
Ridge

Ridge,
send this to me, I can restore it in my shop. I will need the make, model & year.

DOM

[John P.]

Re: shocking development

Thanks to all. I think I need to have a specialist track this down. Don't have enough basic knowledge of electrical issues.

You all convinced me !

[Ridge K.]

Re: shocking development

Ridge,
send this to me, I can restore it in my shop. I will need the make, model & year.

DOM

That would be some pretty good work, DOM!