40 Merc under-dash switches

[Clem Clement]

I'm gingerly exploring my 40Merc. Under the dash on the driver's side there are a rheostat knob for the dash lights and an no/off switch. The dash has mounting holes for the switch which seem factory. I see nothing on the wiring diagram. When I first bought the car in 1956, it had a driver's side spotlight which is now gone.
Gone is the day when I could work upside down... (I turned the switch on and beer flowed out of the horn button...that is factory , right?
Merry Christmas,
Clem

[Zeke3]

Was it a lager, ale or porter?

[1931 flamingo]

Love your humor ! !


MERRY CHRISTMAS and a HAPPY, HEALTHY NEW YEAR ! ! !

Paul

[Clem Clement]

1931 Flamingo,
Thanks. I my retired capacity, I don't have the strength to lug and hug as I used to. Still my life's goal is to help make other folks happy. Thus the silliness in my writing and thinking.
Merry Christmas,
Clem

[Clem Clement]

Parkbrauerei / Park & Bellheimer AG | Pirmasens, Germany ...

Immer schmect

[Zeke3]

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Klingt erfrischend.

[mfirth]

Ich verstehe nicht, i do understand ale tho & CGRISTmas.....

[Clem Clement]

Parkbrau was my fav local beer while stationed in Germany

[Clem Clement]

There is a wire from the ignition to the paddle switch.

[Clem Clement]

The wire goes thru the paddle switch and to the firewall Resister's left end???

[JayChicago]

So this switch provides temporary by-pass of the resister to help with starting, added by a previous owner.

[Clem Clement]

Turn it on for starting and then shut it off? If I leave it on, I cook the coil?

[Ggmac]

Isnt the on off switch for the dome - interior lights ?

[rotorwrench]

The integral instrument lamp dimmer and light switch came later than 1940. I think the 1942 Mercury did have a separate instrument lamp dimmer rheostat but I'm not sure about 1940. Heater set ups could have a rheostat switch for the fan motor but it depends on the heater type whether factory or aftermarket. Dome light switches were either close to the light or on the B-pillar in many old Fords clear up into the 50s.

It's harder to find information for Mercury cars but they did share stuff with the Fords to a certain degree. The dashes were definitely different in the early years but they still had light, throttle, choke, vent, & wiper knobs. Some had overdrive control knobs if equipped and the convertibles had top control knobs. All of them had the column mounted ignition switch till 1948 or so.

[Clem Clement]

This is a 40Merc fordor convertible sedan. No dome light. Dinner rheostat is separate and full of mold. Car has hot air heater. It will come out soon for inspection.
Thanks

[JayChicago]

Originally Posted by Clem Clement

Turn it on for starting and then shut it off? If I leave it on, I cook the coil?

Yes. And yes.

[1931 flamingo]

" switch provides temporary by-pass of the resister to help with starting"


There was a discussion w/diagram on the EFV8 club board about this.
Paul in CT

[rotorwrench]

I don't think a bypass switch for the ignition resistor would have been a factory item. If it is then that would be the first time I've gotten that information. It was likely added by a former owner. This is where photos of unknown things are needed to aid in identification and for future reference to others.

[deuce_roadster]

The dash light switch is integral with the headlight switch on 40 Fords, so I suspect same on a Merc. When the headlights are on, the dash lights are on and adjustable via the rheostat you found.
How is this for not being OT Mike!

[Clem Clement]

I need to sort out the on position and so mark it. I have in the recent past noted that the starter cranks slowly. The switch is mounted on a pierce of small aluminum sheet screwed in place to the bottom lip of the curved dash next to the holes for the dash light rheostat. It is clearly not factory.

I removed and checked the dash light rheostat. The nichrome coil spring used to take off a lower voltage is disconnected at one end.

[Clem Clement]

DR,
You are correct.
Clem

[Clem Clement]

Suggestions, please on how to test this system to determine which way the switch is on. The switch moved front -to-back. The mounting plate is held on by 2 slotted screws. I can't see/feel the other end of the screws. Wire end is hard to reach.

I haven't studied the dissy connection end.

[rotorwrench]

Integral would have the meaning that is is all part of one assembly like the later cars in the 8BA era.

A lot of the old rheostats were actually built pretty well but they do wear out over time. The brush that has light spring pressure, rotates with the turning knob and has contact to the outer circular resistor ring. Usually either the brush wears out, the brush spring breaks, or the circular resistor gets worn though at some point on its circumference by the brush. I've seen reproduction replacements for the 42 through 48 type but I haven't seen the earlier ones so much. They are likely available from some source though. How well they are made is the big question. The dark blue knobs were used on 1940 Mercury so that would likely be the difference from a dimmer on a 1940 Ford Deluxe.

The rheostat would only need connections for one end of the circular resistor and at the rotating brush for variable power drop. Some rheostats have an off position at one end that isolates the resistor from the brush.

You may have to isolate that flip switch to test it to see what setting is ON. If you have a volt meter and the switch is connected, you can attach or probe at the connection to the ballast resistor or what ever it's connected to and see if the voltage changes when you flip the switch but that won't help if you have no access to terminal ends at either the origin or termination of that switch circuit. Spot lights generally always have their own switch near the control handle. Driving lights or some other accessory may have been wired in. It's just hard to tell on our end how to go about helping with this. A person would have to follow the switch circuit wiring to its end termination.

[Clem Clement]

I put a light bulb on the dissy nut and the light did not change brightness with the moving of the paddle switch. (The ign. was on but the car not running.)

[tubman]

Turn the engine over a couple of times. The points may have been open when you tested it.

[Clem Clement]

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I'm more confused. I took the power source from the top of the coil at the knurled nut. I have a grounded light bulb . Either position of the paddle switch and the bulb illumination was low. Going to the battery for both power and ground and the bulb was much brighter.

This Afternoon I looked again at the wires under the dash.( I have the top 3 of my neck vertebra fused so I don't twist very well. To my amazement there is a small pill-like shape which I think is a resistor in the line to the paddle switch. The "pill" has white alfa numeric markings on it.

In my mind the purpose of the bypass is to bring 6 volts to the starting system?

[Clem Clement]

Big discovery!!
With a camping mirror and a better light, I could see the switch. The switch has a collar with on/off tab attached!!! Off is forward. When I get to start the car I will study more.

[slowforty]

My switch started to act up. I by passed the switch and dash light are much brighter now.
and I dont drive too much at night anyway