Quick Thoughts on Turn Signals

[ChrisMinelli]

** I have a service manual and have consulted it, just FYI before suggesting that to me **
 

I have a 52 Plymouth with factory turn signals.  They don’t work and this is my next project.  
 

All lights work.  The brake pedal makes the tail lights light brighter on both sides (21 candlepower versus 3 candlepower).  When the turn signal is turned either left or right that brake light fails to work.  (Example - brake pedal at a stop light will light both brake lights, but when the left turn signal is engaged the left brake light cuts out while the right brake light stays lit).

 

1. I am pretty sure my directional signal switch by the steering wheel is bad.  I have determined the switch is grounded but no electric gets passed it.  Is this a rational assessment?

 

2.  Has anyone tried rebuilding a switch?  NOS is a fortune.  If I can reasonably fix it somehow it would be worth my time to take it apart and re-solder things.  
 

Thanks in advance!

Edited October 31, 2020 by ChrisMinelli

[Hamilton]

So the brake lights work when the turn signal switch isn't activated. 

 

Do the turn signals work when the brake pedal isn't depressed?

_

[Loren]

I have a 52 but doesn't have turn signals, so I have very low experience with this specific car.

I did have a 64 IH Travelall which had a Mopar steering column. The switch for this column if you could find one was in the $400 to 500 range.

I finally broke down and replaced it with an accessory Signal-Stat switch that I got from Snyders Antique Auto, a Ford Model A & T supplier. The cost was $80 and it worked very well indeed, except for the fact it didn't self cancel. (you can get cheap Chinese copies for $29 or even less if your okay with that)

The IH problem was plastic switch parts that could not be replaced. Your switch should be all metal.

The contacts could be corroded which is a solvable problem.

My first thing to look at would be the flasher unit. They wear out or get fussy. Since they are cheap I'd change it just to be safe before tearing into your wiring & switch.

Also remember the only thing you know about a new part vs an old known good part, is that the new one came in a box. I've had bad electrical parts sold to me many times before. Usually they give you another part and put the one you returned back on the shelf!

Also having the right bulbs in place is pretty important. The flasher unit uses the current draw to trigger the on/off action, thus LED lamps don't draw enough current to make the system work. Some even come with huge resisters to supply the load needed and sometimes that isn't enough.

Turn signals are pretty clever they way they work and they don't work the way you might think they do.

I still sit down with a diagram when just changing the flasher doesn't work. 

[DJK]

I second the flasher unit as Loren mentioned.

[squirebill]

Did you get this situation sorted out?  Sounds like the turn signal switch is working as it should by cutting out the brake light circuit on the left light when the switch is put in the left turn position.  I also would suspect the flasher circuit.  With the switch in the left turn position I would run a jumper wire from the hot side of the flasher to the other terminal of the flasher and see if the left light comes on.  If my memory is correct a two terminal flasher has a hot terminal and a load terminal for the light.  A three terminal flasher has a hot terminal coming in and a terminal going to the light and the third terminal is for the turn signal indicator light  on the dash board.  Let us know how you make out.  Regards.

[greg g]

This may seem strange but are the fronts lighting up??  There needs to be enough draw to activate the thermal switch in the flasher.  If the fronts aren't doing their part, the rears won't flash.

 

 

 

 

 

 

[48ply1stcar]

On 10/30/2020 at 9:22 PM, ChrisMinelli said:

All lights work.  The brake pedal makes the tail lights light brighter on both sides (21 candlepower versus 3 candlepower).  When the turn signal is turned either left or right that brake light fails to work.  (Example - brake pedal at a stop light will light both brake lights, but when the left turn signal is engaged the left brake light cuts out while the right brake light stays lit).

I've read this serveral times now, came back today and read it again.  Everything above sounds right.  You should have 2 element bulbs, one element is less bright that is for your tail lights, the brighter element is for the brakes and turnsignal.  If you have your foot on the brake while your turn-signal is on one light should be flashing and the other steady on for the brak.  If your foot is not on the brake just the turn-signal should be flashing.  Mine work this way and so do most trailer lights.

Edited November 6, 2020 by 48ply1stcar
spelling

[Sharps40]

Correct.  With a 2 bulb dual filament set of tail lights the turn signal switch overrides the brake.  

 

If turn signals dont work with the engine running there is a fault but not in design.

Edited November 6, 2020 by Sharps40

[desoto1939]

Yes check the type of bulbs in the front and rear sockets. Also check the flasher unit. I am assuming that you have a 6 volt system. Did someone put in a 12 volt flasher unit. Pull it out of the holder and check if 6 or 12 volt.

 

rich hartung