70 Side Marker Conversion

[70-1600]

Ed:

Here are the two bulbs side-by-side: the 1157 dual filament low profile bulb on the left, the 97 single filament bulb on the right. As I know from my previous research the base dimensions are identical, with two exceptions: first, the type 1157 has two contacts for the two filaments, while the type 97 has one contact; second, the retention tabs on the type 1157 are offset to ensure alignment of the two contacts for each filament (8W and 27W), while the type 97 has the retention tabs aligned. You can see the differences in the picture.

Bulbs Compared.jpg

The overall height of the two bulbs, from the tip of the contact(s) to the top of the bulb, are identical: 1.36 inches. The diameter of the bulbs is also identical: .73 inches.

My conclusion is if you can successfully adapt a 3-wire socket into the '69 teardrop front side marker, this low profile 1157 bulb will fit. If you order these bulbs from the source I listed in the write up (Cruiser Customizing), here's what you'll receive:

Bulbs.jpg

Good luck! If you go for it let us all know how it turns out with a write-up of your own for the '69 model!

-jt

[Ed Mason]

Awesome. Thank you. Be a good winter project!

[spyder]

Nice! Thumbs up!

On a somewhat related note - does anyone have an idea of how to make the parking lights stay on with the headlights on an early car (specifically a 67.5?).

I have added teardrop side markers and want to make them work like the above.

Connect the two wires through a diode.

I had a '66 pickup which would turn off the front parking lights when the light switch was pulled out to the second click, headlights on. Factory designed it that way. Verified in the schematic! I had to add a diode to keep them on in order to pass Texas inspection. It was easy to solder it onto the switch.

[70-1600]

Quick update - looks like "Cruiser Customizing" link I referenced in this write up is bad now. Instead you can just google "Drag Specialties 2060-0202" to find the low profile bulbs.
-jt

[mellis18]

That is exactly what I want to do with my 69. In fact I did an inquiry on this site about it. Great write up and thanks. I'm going to try and do this for both front and rear side markers this winter.

[bikermike]

Nice project. As you probably found, an alternative is to have an on/off flash with a single filament bulb and socket in the side marker by wiring in a 3 to 2 wire trailer tailight converter.

image.jpeg

On the input side, tap into the front turn signal wiring for "left" and "right". Instead of connecting the "stop" wire to brake lights as one would in a trailer, connect the "stop" wire to an existing side marker lead in the car.

The 2 output wires would connect to the side markers and allow the single filament bulbs and sockets to behave as running lights and turn signals.

This conversion is on my list my Z.

On a somewhat related note - does anyone have an idea of how to make the parking lights stay on with the headlights on an early car (specifically a 67.5?).

I have added teardrop side markers and want to make them work like the above.

For adapting the front parking lights in an early car, you should be able make a mod to the headlight switch wiring. Check the wiring diagram. Just wire up the front parking lights to the rear running lights which stay lit in both positions of the headlight switch.

[shifty]

Just wire up the front parking lights to the rear running lights which stay lit in both positions of the headlight switch.

Great idea! So simple and direct, that I never would have thought of it

[bikermike]

If I recall correctly, the bottom terminal on the headlight toggle switch will be live in both the parking light and headlght positions since it feeds the tail lights and dash lights.

I ran with the mod for a while, but realized that I preferred to have the parking lights off when the headlights are on since I am running switchback (white/amber) LED bulbs with clear lenses. I use the parking lights as LED daytime running lights. I don't like the look of them at night.

[twoeightythreez]

[quote="bikermike"]Nice project. As you probably found, an alternative is to have an on/off flash with a single filament bulb and socket in the side marker by wiring in a 3 to 2 wire trailer tailight converter.

image.jpeg

On the input side, tap into the front turn signal wiring for "left" and "right". Instead of connecting the "stop" wire to brake lights as one would in a trailer, connect the "stop" wire to an existing side marker lead in the car.

The 2 output wires would connect to the side markers and allow the single filament bulbs and sockets to behave as running lights and turn signals.

This conversion is on my list my Z.

Actually, if you want to keep the single filament bulb, there is an easier way...simply splice the ground side of the bulb socket to the turn signal power wire. You may have to isolate the bulb housing from the body to avoid shorts (as it is a metal bulb housing), but you would also have to do this with the trailer converter.
Possibly put a new bulbsocket in that has its own isolated ground wire.
Ok it works like this...
When parking lights are on, they will ground through the turn signal filament( to the turn signal ground) and will turn off when the signal flashes because 12v will be present on both sides. When the parking lights are off, the sidemarkers will flash in sync with the turnsignals....(.they will ground through the parking light circuit)GM cars are wired this way from the factory. Yes, when the park lights are on they will flash out of sync, but it saves buying and mounting a trailer converter....which is silly IMO.
The THREE WIRE CONVERSION is awesomeness. though.