Help! Why would my tachometer needle move when I hit the horn

[jmz]

A couple things going on here when I turn the wheel the horn won't work sometimes I read up on the side about needle bearings in the steering column but why would my tach needle jump?

[proporsche]

Hi Jay
in both cases you are loosing your ground to the steering shaft.For the hron to work properly you have to have ground.
I used to fix it like this.let see if i can explain.
In your front trunk compartment is a lid.When you open it you can see the steering joint and a shaft.
I used to put on the shaft additional ground .I cut my self a old feeler gauge about 3 cm long punch a hole in one end and the other end i let touch the shaft like a brush.That will give you additional ground.
That is how i used to fix the horn problem in the 1980`s.Someone might have a better idea.
The tach is jumping also because of bad ground...
Ivan

[Targa Me]

^^^
What he said.

[jmz]

Thank You for that... I'm still a bit surprised and confused how pushing the horn button causes the tach needle to bounce. ...just ever so slightly.

[DonNewton]

I thought it was because you scared it when you hit the horn. I guess you learn something every day. Yes, the lame sense of humor comes with age. . .

[dwight45]

The horn is good for another 5 horsepower.

[jmz]

Haha... Good ones.

[proporsche]

Jay..since you are confused ..have you checked the ground under your steering wheel?? If you remove the wheel there should be cable attached to the little screw on right bottom...
I am telling this just in case you are wondering;-)
Ivan

this one

[jmz]

Originally Posted by proporsche

Jay..since you are confused ..have you checked the ground under your steering wheel?? If you remove the wheel there should be cable attached to the little screw on right bottom...
I am telling this just in case you are wondering;-)
Ivan

this one

I'm going to check the ground I'm sure it needs help. I just didn't think the tach shared any ground connections with the horn so was wondering about that specifically.

[gazzerr]

It's important to chase that short down. There's a lot of unfused circuits behind the dash, specifically around the dash lighting. You can get a big fire and wiring meltdown. Pretty common on these 911's. I have first hand experience ...

[NYNick]

You've got one helluva heel toe action going on if you can hit the horn and the accelerator at the same time with your foot.