Small button under 1958 dash help

[fishchipper]

Someone is going to immediately know what this is, but I have a 1958 Coupe Deville, and there is a small button directly underneath the dash.  I'm attaching an overview and then a closeup.  I've pushed it and spun it, and it does nothing, but I know it has to do something.

Overview under ignition:


Closeup of button:

[TMoore - NTCLC]

I am not too familiar with your model, but that button looks exactly like the trip odometer reset button in my cars - you can try pushing it in, and then spinning to see if it moves the trip odometer dials in the speedometer.

If that is not it, then I am sure others will chime in shortly with exactly what that does on your model -

[Bobby B]

I don't have your year car, but to me it looks like the odometer trip reset knob. Sometimes you have to pull down and turn, and sometimes you have to spin it a few times in one direction to get it to catch. It could also be broken, rendering it ineffective.             Jon S Help?? 
                        Bobby

[fishchipper]

I never checked the odometer with it, but that might be it.  Now that you wrote that, when I pushed it, it felt like that's what it might be doing.  Thanks.

[Jon S]

Yup, it's the trip odometer re-set.

[TonyZappone #2624]

Exactly what it is.  On my car it is also the gas gauge.  When I fill the tank, I set it to zero.  At 100 miles, I refill the tank.

[The Tassie Devil(le)]

Boy, if I had to refill my tank after doing 100 miles, I wouldn't be able to get much in.   It wouldn't even be 1/3rd. empty.

Bruce.

[Jon S]

Bruce -

I'm thinking Tony likes to keep his tank topped off, but at 10 - 12 MPG, that's about 1/2 tank.

[Gene Beaird]

Exactly what it is.  On my car it is also the gas gauge.  When I fill the tank, I set it to zero.  At 100 miles, I refill the tank.

Funny, but I have a 3rd Gen Camaro like that, until the electronic speedometer went out. 

[fishchipper]

Thanks for all the replies.  I'm sure that what that button is "supposed" to do, but something must be disconnected behind the dash because when I pushed it, it did not reset.  I guess that is why I was confused in the first place.  Sounds like another project just got added to the list.  At least we are enjoying driving her around during our few months of pre-summer oppressive heat in Houston.

[Jon S]

You have to push it up then turn it counter-clockwise to re-set trip odometer to 0000

[Cadillac Jack 82]

So thats what that is.....I have the same thing but the button is larger in diameter

[Walter Youshock]

Chances are the knob dry rotted and someone replaced it.  That brown one is correct.

Is that an aftermarket ac unit under your dash?

[fishchipper]

You have to push it up then turn it counter-clockwise to re-set trip odometer to 0000

That worked. Thanks Jon.