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'52 merc troubles

I am having some electrical “problems” with my '52 merc in regards to the turn signals and the stop lights. My turn signals don’t work at all and only the rear left hand stop light works. So if I replace the turn signal switch should that solve my problems, it seems like all the wires for these different things go through this switch. When I took out the old swith the left front turn signal started to blink, but that was it. Also whenever I turn on my parking lights or headlights the green arrow for the right hand turn signal comes on, what would be causing that? Any suggestions or input on this would be greatly appreciated!

I just want to add a “correction”, when I started moving the old switch before I took it out when I moved the switch the front left turn signal began to work, this did not happen after I took out the switch.

You are correct that these wires all go through the turning signal switch. It is set up this way so that when you signal a turn and at the same time step on the brakes, the turning signal will keep blinking. The turning signal and the brake lights share the same filaments in the tail lights. A defective switch is a distinct possibility.

1952 Merc.

I miss these old time wheels. Nice ride BTW.

One thing for sure being a 1952 vehicle, there’s no multi-function switch to worry about.

It’s possible the switch is worn out.

I suspect a short someplace, as lights other than the ones controlled by a certain switch should not be activating.

Ie., turn signal switch only controls the turn signals.

The brake light switch is activated by an adjustable switch which is mounted to make contact with the brake pedal arm.

Headlights activate with the headlight switch ONLY.
The headlight dimmer switch (the hi/lo beam switch is a metal foot switch on the floor next to the drivers left foot (Close to the firewall) and ONLY controls that function.

In time the floor mounted dimmer switch will get corroded from moisture, humidity or water off shoes/boots, etc. and will malfunction and the only cure then is to replace it. It can cause more than dimming faults.

Unless an attempt has been made by someone to install a multi-function switch in the steering column that’s the way they should work.

Check all fuses and trace the wiring to the source of the short.

Make sure all wiring connections do not come in contact with one another (especially when installing the switch.

Somehow you are going to have to find a wiring diagram of this vehicle to do this.

It shouldn’t be too hard to trace as the wiring systems those days was reasonably simple.

Make certain all the bulbs are the correct ones and also do a thorough check and cleaning of the bulb bases and ground connections.

I suspect your have grounding issues at the bulbs. When you turn on the parking lights, the power to the low-watt filament cannot find ground at the bulb connector, so it is back-feeding through the high-watt filament, and energizing the turn signal circuit to find a ground elsewhere, probably the ground at the other bulb on the circuit. check all the bulb connectors for good, clean ground.

I would put the turning signal switch on the prime suspect list. Many years ago, I installed turning signals on a 1947 Pontiac that I had purchased. In those days, turning signals were not standard equipment. The rear lights each had two filaments–one for the tail lights that came on with the headlights and parking lights and the other for the brake lights. The filaments used for the brake lights also served the turning signals. I remember that I had to run a separate wire from the turning signal switch to one of the rear lights. I removed the brake light wire from this light and attached this lead from the turning signal switch. I also ran one lead from the turning signal to the brake light switch which was on the master cylinder. The reason the turning signal switch was involved is that when one signaled a turn, let’s say a right turn, and stepped on the brake, the right light had to blink while the brake and turn light filament came on steady on the left light. The same thing must happen, except to the opposite lights when signalling a left turn. This wasn’t a multi-function switch. I also had to replace the sockets in the parking lights for a dual filament bulb and run leads to each parking light. There was also a lead that went to a power source and there was a flasher and socket as well that came in the kit. The switch had a rubber roller and was mounted so that it turned as the wheel turned and the turning signals would cancel. Virtually all American cars of the 1940’s and 1950’s had this set-up so that the same filaments in the rear lights served the brake light function and the turning signal function. This necessitated the brake light power going through the turning signal switch. As I remember, I bought the turning signal kit from the Montgomery Ward catalog, although I’m certain it was available at Sears and Western Auto as well.

One thing you should remember I did a 1958 olds conv we put in new light bulbs one brack light worked one turn light worked only ne tail light worked . one parts store said that the new numbered bulbs would work . not so . we went to napa and got all the bulbs with th same mumber from 1958. and every thing lights just fine. I think because the new bulbs use different residince they did not work. . look for the
correct bulbs. this has nothing to do with your problem . just a note

When I was working on this car the other day I put the turn signal wires together and the signals worked! So the switch was bad! I also make a slight mistake when I changed the old bulbs because I must have put the turn signal bulb in the dash light socket and then put them in the wrong hole on the dash because the signal for the right started make the dash light blink, that’s why the green arrow comes on with the dash lights… However the rear right turn signal still does not work, but the tail light on that side does… Must be a short or broken wire somewhere… One other thing I am wondering about, when I turn on the ignition the gas gauge used to move, but now it doesn’t could the tank jsut be too low with fuel, could the sending unit be bad? I have checked and there is current to the gauge…

Do the turn signal and the brake light work on the same filament? If so the filament for those could just be bad on that bulb since the tail light works just fine.

Yes, the rear turning signal and the brake light use the same filament on your Mercury. The tail light is on its own separate filament.