ok, i'll copy and paste this from a thread from 2005. i tried it and it really works. i have been driving the freeways and determined it would be alot safer if my front side-marker lamps would blink as well. here's the mod i performed, and did it without a test light like it explains. just use common sense to determine which color wires do what, and you can do it without having to use extra wire. all i needed was a razor blade, needle nose plyers, and a roll of electrical tape. here it is:

The whole job involves only re-routing one wire on each side. You just
need to check carefully to ensure that you've identified the right ones.

1) Switch on the vehicle's parking lights and 4-way emergency flashers.
You don't need to run the engine during this test unless the battery
is severely low.

2) Using the test light on the wiring going into each turn signal, identify
the wire carrying the blinking turn-signal power.

3) Using the test light on the wiring going into each front side marker
lamp, identify the ground wire (the one that's _not_ hot).

4) Switch the vehicle lights off. You don't need to disconnect the battery.

5) In the next step, you're going to snip the ground wire coming from the
marker lamp and connect that wire to the turn signal's power feed. Work
out the best way to snake the marker lamp ground wire around to a point
where you can tap it into the turn signal's power feed wire, using an
extension of 14-gauge wire if necessary. Pay attention to what cavities
or openings might be filled when you reinstall the light assemblies, if
you removed them previously. You don't want to pinch the rerouted wires.

Note: Don't get confused here. The idea is to run the ground wire
FROM the marker lamp TO the turn signal. Currently it runs
from the marker lamp into the wiring harness and grounds
somewhere. You're _not_ trying to connect the harness ground
to the turn signal!

6) Cut the ground wire coming from the marker lamp, giving yourself as much
wire length as possible from the marker lamp to the cut point. Tape the
cut end of the ground wire that goes into the vehicle harness and stuff
it out of the way.

7) Connect the ground wire leading from the marker lamp to the hot lead
going to the turn signal on that side. Tape or otherwise weatherproof
the connection, and you're done.

 

hey, can you get a picture of how you did this?

I am a learn by seeing. yes I see text, but pictures help a bit more. also, what year of truck did you do this on?

 

so the pwer goes through the marker light, then through the turn signal bulb to ground, so the turn bulb would glow dimly until it gets power from the turn sig switch, then the side marker would go out and the turn signal would burn bright... I never noticed that the side marker doesnt blink, and it should.... I give this mod 2 thumbs up!!

 

subscribing. May do this tomorrow

 

ok, i'm out to take some pictures...

 

thank you!

 

Quote:

Originally Posted by bashby

...then the side marker would go out and the (front) turn signal would burn bright...

My 1970 Mustang operated that way from the factory, I thought it was pretty
cool!

But, it had separate lamp assemblies for the front/rear & side markers. I suspect
these trucks don't operate this way from the factory because the rear housings
are dual-purpose - for both the rear & side lamps. So, if you make this mod, and
then look at the vehicle from a side view, it's gonna look like a confused school
bus...

 

here are the pictures of the mod already done, but i'll explain how i did it with the colored arrows.

this is the drivers side: the RED arrow is the black ground wire coming from the side marker lamp. it used to mount to the fender with this other wire shown at the GREEN arrow. i just pulled it out of the clamp up there on the fender and it was already to go. i spliced it with the green blinker wire shown in the WHITE arrow. the BLUE arrow shows where i spliced it into the harness. as for a tip: make sure you don't cut the black wire with cutters, then you won't have enough length to drop it down to the harness. just pull it out of the clamp with your hand. takes a little chest hair to do it.


this is the passenger side behind the battery: you don't have to remove the battery to do this, but it would be helpfull when taping back up the harness. this side is the same concept, but you're NOT going to pull the black ground wire shown with the RED arrow out of a grounded clamp. you're going to snip it in two as close as possible where it enters the taped harness. then where the BLUE arrow points to the harness, untape a few inches to expose the wires. there will be a white with blue stripe wire that goes down to the blinker. i shaved the insulation off to expose about an inch of the copper. i then folded it in the middle and then twisted the black ground wire to it and done. th remaining ground wire that you cut will be fine as is, just tape it up. then tape up the harness and good to go. tip: just make sure you plan before you cut, to make sure you are going to have enough wire to work with

 

of doing something like this as I wanted those marker lights to blink too. Good idea, cutting the ground wire and tapping into the hot lead of the turn signal. It will use it as a ground when the power is off. I was going to use relays and junk like that, your way is much simpler. Tomorrow I'm going to do this as its so simple.

THANKS!

Ryan.

 

I REALLY liked the sequential tail lights the Shelbys & cougars used back then. I'll try this mod, too, WA drivers are not so observant. More so in a F250 than my Trans am though.....

 

I did this mod years ago on my 85', then I carried it over with my body swap. I need to do it to my 93' now. Free mods are the best.

 

This is awesome. Does anyone have a video of this mod in action?

 

well i just did the mod. I love it. I wanted to do this 15 years ago on my 83 but didnt know how. Thanks. I cant believe Ford didnt make that a dual filament bulb from the factory

 

I'm a little confused....how is the side marker light working without a ground, if you hook the ground for it to the positive wire for the turn signal? How does that work?

Thanks for the pics, btw.

 

The marker ground back feeds thru the turn signal when the markers are on. Then the blinker brakes the path to ground when the turn signal is turned on ,hence making it blink opposite of the front turn signal