1959 Mercury/Ford Headlight Knob?

[Stephenorf]

I have this 1959 Mercury Monterey and I'm wondering about the headlight switch and knob. It looks like a threaded shaft, and pushed in (lights off) the end of the shaft is flush with the dash. Does anyone have a 1959 Ford/Mercury who can compare to what I have? The knob isn't threaded but has a setscrew. For now the knob just slides onto the threaded headlight shaft, but cannot operate the switch. If I take the knob off, I can manipulate the shaft with a pair of needle nose pliers and work the lights.

The knob seems to match the rest of the knobs on the dash, but uses a setscrew to attach to the shaft. If I pull the shaft out and put the knob on, the knob hits the dash before the shaft is pushed in all the way (the driving lights stay on). I'm thinking I have the wrong knob, or maybe an incorrect light switch.

The first pic is the knob next to a couple other knobs on the dash...perfect match!

Second pic is the knob on the switch. Looks good but it isn't attached.

Third pic is the Headlight Switch shaft fully extended (pulled out). It is a little blurry, but there is a ridge just passed the threaded portion where the shaft diameter is reduced. I assume that the set screw is supposed to be tightened here to prevent the knob from being pulled off the shaft when the switch is pulled out.

The fourth pic shows the headlight switch shaft fully retracted (pushed all the way in). If the know is put on the shaft and the set screw is tightened in the groove, the shaft will not push this far in, as the knob hit the dash.

Any Ford, Lincoln or Mercury owners here with a headlight switch & knob they'd like to examine and compare to what I have? Thanks in advance!

 

[Stephenorf]

Update: OK, a little sleuthing and I see that the headlight knob is indeed the exact same knob used elsewhere on the instrument panel (11666), so I know I have the correct knob (see pics below). I guess I just have to figure out how to secure it to the shaft correctly so that the knob doesn't interfere with the in/out movement.

Interestingly, I would have thought the set screw would be orientated towards the bottom of the knob, so as to be hidden from plain view. But per the exploded diagram below, it appears the set screw for the headlight switch was orientated toward the top of the knob.

Also interesting, there is no bezel for the headlight switch.

 

[mercman from oz]

Diagram of Instrument Panel - 1959 Mercury - Stephenorf

 

[KULTULZ]

BPN 11650 should be the retaining bezel. It with BPN 11A653 should allow adjustment of the switch (11654) for the stem to operate properly.

Is the knob metal or plastic? Any signs of stripped threads where the shaft enters? The set screw should be pointed downward so as not to detract from appearance.

 

[58Yeoman]

BPN 11650 should be the retaining bezel. It with BPN 11A653 should allow adjustment of the switch (11654) for the stem to operate properly.

Is the knob metal or plastic? Any signs of stripped threads where the shaft enters? The set screw should be pointed downward so as not to detract from appearance.

I agree with KULTULZ, the screw should point down. It's probably illustrated to easily show where it goes.

 

[Stephenorf]

BPN 11650 should be the retaining bezel. It with BPN 11A653 should allow adjustment of the switch (11654) for the stem to operate properly.

Is the knob metal or plastic? Any signs of stripped threads where the shaft enters? The set screw should be pointed downward so as not to detract from appearance.

The knob is metal, and surprisingly heavy for its size. I would guess it is original to the car. It exactly matches all the other control knobs on the instrument panel. And it is in excellent condition.

I don't see any stripped threads on the shaft. I'm wondering if the knob is supposed to screw onto the headlight shaft. Although that doesn't seem to make good engineering sense, since part of the headlight control is twisting the knob left and right to turn on the interior lights and adjust the gauge illumination brightness. If the knob screwed on, then it seems it could easily un-screw when the knob was turned all the way the left. I'll play around with it some ore tomorrow and report back.

 

[Stephenorf]

I agree with KULTULZ, the screw should point down. It's probably illustrated to easily show where it goes.

Yes, I think you're right. Having the set screws are at the bottom makes more sense.

 

[Stephenorf]

BPN 11650 should be the retaining bezel. It with BPN 11A653 should allow adjustment of the switch (11654) for the stem to operate properly.

How do these parts work together? I was wondering about 11A653, as I wasn't sure of its function.

 

[KULTULZ]

The knob is metal...

I don't see any stripped threads on the shaft. I'm wondering if the knob is supposed to screw onto the headlight shaft.

Although that doesn't seem to make good engineering sense, since part of the headlight control is twisting the knob left and right to turn on the interior lights and adjust the gauge illumination brightness. If the knob screwed on, then it seems it could easily un-screw when the knob was turned all the way the left.

The set screw would stop it from loosening.

If the knob is not threaded internally maybe possibly the wrong shaft is on the car?

How do these parts work together? I was wondering about 11A653, as I wasn't sure of its function.

They (11650 and 11A653) would steady the HDL SW itself from moving while using. If there is an adjustment feature available you would need a WORKSHOP MANUAL or someone who has previous experience with the car model. I never got the pleasure.

Do you have a 59 MERC SHOP MANUAL?

 

[Stephenorf]

Do you have a 59 MERC SHOP MANUAL?

Yes, I have the 1959 Mercury Maintenance Manual...well used and very handy. I don't see anything in this one about adjusting the headlight switch shaft/knob. Just general operations instructions plus removal & installation. I doubt it has an adjustable shaft, but I guess anything is possible with Ford engineers in the late 50's.

 

[rotorwrench]

Many of the old Fords have a dimmer rheostat as part of the headlight switch. Rotate the knob one way for dim and the other for bright. This may be why it has a set screw but I'm not familiar enough with the 59 models to know if this is fact or not. The photo in the manual seems to indicate that the switch has the instrument light dimmer rheostat.

 

[Stephenorf]

Many of the old Fords have a dimmer rheostat as part of the headlight switch. Rotate the knob one way for dim and the other for bright. This may be why it has a set screw but I'm not familiar enough with the 59 models to know if this is fact or not. The photo in the manual seems to indicate that the switch has the instrument light dimmer rheostat.

Hi, yes the 1959 Mercury has the dimmer (rheostat) built into the light switch. And the knob definitely has a set screw too. I haven't fiddled with it yet today, but I'm perplexed regarding the fitment of the knob on the switch, whereas the switch shaft, when pushed all the way in, is flush with the dash. The knob seems to interfere with the full movement of the switch in the "off" position.

 

[40cpe]

I think you have the wrong stem in the switch, or the wrong switch. A stem designed for a set screw will have a flat side on it, no threads.

No telling what has been done in the past to keep the car going.

I would consider removing the stem from the switch and lengthening it.

 

[Stephenorf]

I think you have the wrong stem in the switch, or the wrong switch. A stem designed for a set screw will have a flat side on it, no threads.

No telling what has been done in the past to keep the car going.

I was thinking the same thing. I guess for now it is a low priority to source a correct switch for the car. The switch that is in the works. I was hoping someone else with a '59 might pop off the knob in their car so we could compare.

 

[40cpe]

might pop off the knob in their car so we could compare.

"pop off" one of the other knobs to see what that stem looks like.