High Level Stop/Tail and Direction Indicator Flashers for T-Types

When I purchased my TC in 1960 it was fitted with Lucas L549 stop and rear lights mounted half way up each rear mudguard in a similar style to the later TD. These, in conjunction with the standard ST51 ‘D’ lamps, gave visible and reasonably high level stop/tail lights and served their purpose well, until a racing accident at Silverstone in 1965 necessitated a complete rebuild of the car. By the time the rebuild was completed some years later I had been influenced by thoughts of originality. I reverted to Lucas ‘D’ lamps (ST51) performing stop and tail light functions with direction indication being carried out by the flashing of either the left or right hand brake light, as was the practice for some export markets.

This situation, supplemented by hand signals, is a poor arrangement and unacceptable in today’s traffic conditions.

After looking at many alternative solutions to the problem I decided to develop my own system that could be converted back for originality purposes relatively quickly.

Design Objectives

– High-level direction indication with amber lenses.
– High-level rear and brake lights to supplement existing ST51 ‘D’ lights.
– Retain a ‘period’ appearance unless function was compromised.
– Keep the design independent of the spare wheel or luggage rack.
– Avoid modification of the body i.e. no holes!
– Avoid using the petrol tank side plate retaining bolts due to worries over their robustness.
– Achieve simple design reversibility for purposes of originality.

Location on Body

In the interest of originality I had decided that no mounting holes would be drilled and I had discarded using the tank side panel bolts due to the worries over the integrity of their fixing to the tank sides. (60+ year old projection welded studs?)

The two possible remaining locations were the two bolts clamping the tank straps to the body just under the hood line, or the tank straps themselves. Using the tank straps seemed a neat solution, and to avoid drilling holes for locating studs to protrude through the straps I opted for clamping slender brackets between the straps and the rubber backing strips. This would give me plenty of scope for deciding the optimum height of the lamps and ensuring that the two mounting brackets could be positioned out of sight behind the spare wheel.

The Design

I had observed that some models of Morgan, various classic cars, kit cars and motorcycles had used chromed tube extensions from various parts of the body on which to mount lights.

I decided to go for a simple chromed tube assembly that would be mounted on two slim brackets clamped under the tank retaining straps. The D.I. lights would be located on each end of the tube and the high-level rear/stop lights would be mounted on adjustable brackets that clamped to the tube. All wiring would be out of sight inside the tube and then run discreetly down the side of the right hand tank strap, behind the spare wheel, to the chassis and be connected to the main wiring harness.

Materials and Tooling

After a little experimentation I decided that the mounting brackets could be made from 1 inch x 0.032-inch brass strip, which after forming, should have adequate stiffness.

Tooling for the brackets was made from three plates simply made on the bench from 60mm x 6 mm bright drawn steel strip, which were bolted together to make up the die. A simple stepped punch was turned from 9/16” diameter bright drawn steel bar.

The design of this tooling enabled the two mounting brackets to be accurately formed on the bench with a medium sized vice. The die and stepped punch enabled a swaged hole to be formed in the bracket, which gave good location on the tube and provided for a good filet of solder on assembly. In addition, using the same tooling the right angle bend could be accurately formed.

At a later stage an interchangeable plate also enabled the accurate manufacture of the rear/stop light bracket, which had a rolled end to accommodate the clamping feature.

Brass tube ½’’ OD x 16swg x 33.25 inches long was chosen, having sufficient wall thickness to accommodate an M10 x 1.25 internal thread at each end and sufficient bore to carry the wiring.

The raw materials were supplied on line from Reeves Model Engineers.

A soldering fixture to ensure accurate bracket positioning and alignment was made from 40 x 40 x 3mm angle iron and this as it was easily bench mounted in a vice, provided a very useful assembly fixture when the wiring was installed.

After soldering, the cross tube assembly and the four light mounting brackets were bright chrome plated.

Lights and Electrics

I had purchased some time before a pair of pedestal indicator lights with full amber lens with 95mm chrome tubes from Stafford Vehicle Components Ltd. These had the size of lens that I needed. Initially I mounted these on chassis mounted brackets, but was not satisfied with the results. By removing the chrome tubes and making up two adaptors that had M10 x 1.25 threads I could fix these lights to either end of my cross tube, with the wiring passing through the tube.

I initially searched for ‘period’ looking stop and tail lights that I could incorporate but realised that strip L.E.D. lights would provide a neater solution. I purchased a pair of short L.E.D. stop lights (LEDST5) which were being sold as internally mounted 3rd brake lights by Car Builder Solutions

These lights had 14 L.E.D.s in a strip mounted behind a plastic red lens. I needed each unit to be both an independent rear and stop light so I modified the L.E.D. motherboard. With the addition of extra wiring half the light unit operated as the stoplight and half as the rear light. The plastic cases were modified with the addition of threaded brass inserts so they mounted on brackets that clamped around the cross tube. As these lights were designed for internal use, weather protection was provided by ‘potting’ all the internals with silicon gel. Wiring for these lights enter the cross tube by means of holes drilled on the underside.

Standard automotive cabling was used supplied by Autosparks with correct colour coding to extend the existing harness. By the addition of a green/purple wire to the harness running from the stop lamp switch via the Lucas DB10 relay unit to the rear of the chassis the stop lamp operated independently once the No. 5 terminal on the relay unit had been by-passed.

Reversibility

Reversibility, if required can be achieved simply by releasing the cross tube assembly complete with lights from under the petrol tank retaining straps, disconnecting the wiring from the main wiring harness and reconnecting the green/purple wire from the brake switch to the No 5 terminal on the flasher relay unit.

(Click diagram for bigger view)

Ed’s Note: As you will have gathered from the introduction to the article, the author (Jim Pielow) has owned his TC since 1960 and raced the car in the 1960s. It would be interesting to know how many custodians have owned their T-Type for over 50 years – I bet there are quite a few!

There are a number of solutions to the problem of securing better visibility for the stop/tail lights and flashing indicators but this is the first I have seen that utilises the tank straps.