TR4A lighting logic

[Christian]

Dear all,

I am currently restoring my TR4A (from February 65) and try to figure out the logic of the lighting switches. The car was originally sold in Germany as LHD. I have a two position pull switch in the center console as well as a three position lever (each position "snaps in", so no dipping) on the steering column. For whatever reason, the car (as long as I've had it) never had a foot-operated dip switch.

What is the (original) logic of the two switches. What does the dashboard switch do in the different position and what would be switched by the steering column lever? I guess I am confused a bit by the fact that is has three positions... 

Also, was the TR4A ever sold without a foot-operated dip switch?

I'd be very grateful for a short explanation of the logic!

Christian

[Tr4aJim]

Christian I have a ‘65 TR4A as well, and mine is LHD. The lighting on my car is as follows:

- lighting stalk up - no lights

- lighting stalk first position down- running lights

- lighting stalk second position down - headlights + running lights

- lighting stalk pull toward wheel (any position) - flash-to-pass (momentary)

- foot switch - high beams on/off

- only light related dash switch is the reostat for the dash light brightness 

Note - if you are rewiring the light switch, there is an error on some TR4A wiring diagrams related to the flash-to-pass connections.

Note 2 - the power from the battery always goes through the light switch when the headlights are on. For period headlights, there wasn’t much draw, so this wasn’t an issue. However some modern headlights can draw enough power to overheat the light switch to failure. Therefore if high draw headlights are fitted, it is prudent to add solenoids to the circuit, so the switch is bypassed when the headlights are on.

Jim

Edited August 15, 2023 by Tr4aJim

[Christian]

Hi Jim,

thanks for this! Looks to be quite different from the setup I have… I’m not even sure my stalk has a pull toward wheel function, need to check.

while the positions of the stalk make sense, I then have no idea what the switch in the center console would do?

Regarding your Note 2, that raises another question: yes, someone had already upgraded to H4 headlights. They have opted for Headlamps with pilot light. As the 4A already has the side markers, I do not really see the point of those? Do you have pilots in your headlamps?

Christian

 

[Tr4aJim]

Christian, it sounds like a previous owner did some nonstandard modifications. Could the dash switch be for emergency flashers? Or maybe they bypassed the stalk mounted headlight on/off switch? Sounds like you may have to do some wire tracing.

I have the standard low/high beam type.

Jim

[BlueTR3A-5EKT]

Is the pull switch in the centre console for the heater fan?

[Ralph Whitaker]

16 hours ago, Christian said:

Dear all,

I am currently restoring my TR4A (from February 65) and try to figure out the logic of the lighting switches. The car was originally sold in Germany as LHD. I have a two position pull switch in the center console as well as a three position lever (each position "snaps in", so no dipping) on the steering column. For whatever reason, the car (as long as I've had it) never had a foot-operated dip switch.

What is the (original) logic of the two switches. What does the dashboard switch do in the different position and what would be switched by the steering column lever? I guess I am confused a bit by the fact that is has three positions... 

Also, was the TR4A ever sold without a foot-operated dip switch?

I'd be very grateful for a short explanation of the logic!

Christian

I`m only guessing here, but it sounds a similar arrangement to the Vitesse I had, where the 2 position switch on the dash sent power to the stalk switch on first click, the second click turned on the panel lights. Once the first click was activated the stalk switch 3 positions were sidelights, headlight dip, headlight main.

Ralph

[ianc]

If you wish to reduce the current drawn through the light switch, have a look at my article in TR Action 296 (March 2017) - accessible through the club's website if you login.

If you don't have access, send me a PM with your email address, and I'll send you a MS Word version of the article.

Ian Cornish

[Christian]

3 hours ago, Ralph Whitaker said:

I`m only guessing here, but it sounds a similar arrangement to the Vitesse I had, where the 2 position switch on the dash sent power to the stalk switch on first click, the second click turned on the panel lights. Once the first click was activated the stalk switch 3 positions were sidelights, headlight dip, headlight main.

Ralph

Hi Ralph,

that seems to make sense, maybe this is how it is supposed to work on my 4A. 
The three position stalk switch does have a pull towards wheel function.

This setup would also explain the absence of the foot operated switch.

Christian 

 

[Christian]

The attached image shows the switches on the center console. Light switch is second from right. This seems pretty original to me.

Also, on the heritage certificate it mentions a steering wheel lock as option (mounted on the column, the ignition key goes between the knees), so the ignition wouldn’t be operated from the console.

[Christian]

Another question: does anybody have pilot lights in their headlamps in addition to the side markers on the TR4A?

[Lebro]

Quite a lot of people do, I did for a while, but now have only the lower LED white / amber sidelights, & H4 LED headlights.

Bob

[Z320]

4 hours ago, Christian said:

Another question: does anybody have pilot lights in their headlamps in addition to the side markers on the TR4A?

Yes

[tthomson]

On 8/16/2023 at 11:31 AM, Christian said:

Another question: does anybody have pilot lights in their headlamps in addition to the side markers on the TR4A?

Yes. In my impecunious time 30 years or so ago,  I replaced the reflectors in my TR4A, and the only ones I could find within my price range had pilot lamp holes, so I added LEDs as additional side lights, rather than leave anomalous "holes" in my headlamps.

Edited August 20, 2023 by tthomson