HOW TO: Blinking side markers

Dimebag · Post by **Dimebag** » 13 Apr 2008 18:29

Today I finally did this mod and discovered how ridiculously easy it is. There has been some previous discussion regarding this, so I hope this satisfies inquiring minds.

This is what the stock wiring looks like (driver side):

As has been previously discussed, the theory here is that we use the front signal bulb filament as the side marker light's path to ground. When the signal lamp is not illuminated, the side marker light is lit. When the signal lamp is activated, it creates a situation where there is +12V on either side of the side marker light filament - the potential difference become 0 Volts, thus causing the side marker light to extinguish while the front signal lamp is illuminated.

Some folks go to great lengths to preserve original equipment wiring when performing mods. I'm not one of those, as you will discover in this tutorial.

The first thing to do is cut side marker lamp ground wire at the splice connector. (You can use a new bullet style splice connector if preserving the original wiring means a lot to you)

Congratulations, you're possibly half way there! All that remains is to splice your newly liberated ground wire to the front signal lamp power wire. There are a variety of splice options. This squeeze type is not my favourite, especially in the engine compartment (mostly for environmental considerations - corrosion etc) but it's what I happened to have on hand.

So in your excitement, you rush to test your new 'aftermarket' option... but wait! What the f&%*@ - It doesn't work?? grumble grumble That John guy is full of horse manure. Ahhh yes. This happened to me - so what happened? The signal came on but wouldn't 'flash' and the the side marker is still on. This means that the side marker is still finding a path to ground. But how is that possible since we cut the ground wire and spliced it to the front signal power wire?

Dimebag · Post by **Dimebag** » 13 Apr 2008 18:37

It turns out that the side markers were being grounded through the metal body of the lamp housing through the mounting screws to the retaining clips on the fender. This was confirmed when I removed the screws, let the fixture hang as in the picture, and everything started working as it should.

A trip down to the auto parts store netted some nylon inserts to insulate the mounting screws from the metal fender. I suppose if you have fiberglass fenders you won't have this problem. I had to ream the clip holes slightly so they would accept the new nylon inserts.

Problem solved! But the signals sure are slow. Not slower than before, but while I'm working on the signal system, lets deal with that too...

Dimebag · Post by **Dimebag** » 13 Apr 2008 18:45

I still had the factory bi-metalic turn signal switching unit installed. It's pulses at a decent rate when the motor is above 2000 RPM, but at 600 RPM standing at an intersection they are impossibly slow.

The OEM flasher is secured to the dash frame behind the fuel/temp gauges (silver can with white plastic connector on top of it, center of photo)

$7.00 later I'm in business with a new 'electronic' flasher that plugs right in - a nice constant signal frequency no matter what the revs are at.

And there you have it folks. All's well that ends well.

Post by **jason** » 13 Apr 2008 19:09

Nice work John, funny enough, I was just talking to Keith about this today!

Post by **qwik510** » 13 Apr 2008 19:15

Hey John,

I have been meaning to do that too. I had read about it in the first issue of the Dime Quarterly. The said to use nylon screws.Either way, glad to here it works.

Here is a link to the DQ article:

http://dimequarterly.tierranet.com/arti ... _lite.html

scotth510 · Post by **scotth510** » 14 Apr 2008 20:36

Does anyone know if that electronic flasher will work for a 68 510?
Scott

68Datsun510 · Post by **68Datsun510** » 27 Mar 2018 04:52

scotth510 wrote:Does anyone know if that electronic flasher will work for a 68 510?
Scott

Yes

Post by **Byron510** » 27 Mar 2018 06:27

Thread from the dead!
But still a good modification- thanks for the bump, it was entertaining as these Realm memeber above have long moved on with exception of David. But the modification is still a good one.

Just for refference, the 68 side marker light was never an a marker light in the first place, and came factory that year as a turn signal light only, so in reverse you could gain a side marker light out of a 68 with this modification.

Byron

Dimebag · Post by **Dimebag** » 27 Mar 2018 08:22

68Datsun510 · Post by **68Datsun510** » 27 Mar 2018 08:41

Byron510 wrote:Thread from the dead!
But still a good modification- thanks for the bump, it was entertaining as these Realm memeber above have long moved on with exception of David. But the modification is still a good one.

Just for refference, the 68 side marker light was never an a marker light in the first place, and came factory that year as a turn signal light only, so in reverse you could gain a side marker light out of a 68 with this modification.

Byron

Yeah, I saw the last post date and just went for it! Ha! Funny though on my 68, it was definitely wired only as a sidemarker, and all original wiring. PL51024822, so, lowish serial #...? Have a 69 currently with the same mod! =D

Post by **Byron510** » 27 Mar 2018 16:37

Dimebag wrote:

Awesome that your still lurking John - hope you are doing well.

Cody - I had to go out and look at my 68 in the driveway to see if it could be hooked up either way on my '68. But nope, the non US MY '68 cars seem to have the fender light only as a signal light, the factory wiring can't be hooked up in reverse without cutting or modifying. But I had the check.

Mines a relatively low number car as well P05174 (not PLXXXXXX as it's a 1300 car), but both my 06061 car and my 35XXX serial number car were wired with the side fender light working only with the signal light, but all were non USDM cars.

I know that the MY'69 and later cars we got in Canada as noted above in John's post were identical to the USDM cars in this regard, all side markers were just that - side markers from 69-73 in both the US and Canada.

Still a great mod, though - and still an enjoyable thread from the dead relapse

Byron

Post by **Stu** » 04 Mar 2021 09:57

Yep, dragging up an old thread, but wondering if with this mod the side markers blink when the marker/parking lights are off? I understand that when the lights are on, the turn signal interrupts ground and causes the side marker to 'flash', but when the lights are off, I don't see a ground path to make the marker lights illuminate/blink. Would like to have my side marker lights flash whether the parking/headlights are on or off.

Post by **datzenmike** » 04 Mar 2021 11:47

Occam's razor.... The simplest solution is probably the best. Drive with your headlamps on. If you aren't you should be. We can all agree that today's drivers are for the most part incompetent. If you are under 50 you may have some impairment too. I mean no disrespect but newer drivers relay too heavily on their vehicles to save them. They look down the road at an intersection and if they don't see headlights, think all is clear. Most cars have daytime running lights and a Datsun should too. Not to see but to be seen by other drivers. I always run with my HIDs on.

The turn signal doesn't affect the ground it applies +12 to the old ground side and the light goes out. (because +12 on both wires to the side marker bulbs) In the mean time the front and rear turn lamps light. When the flasher unit turns off the +12 is removed and the side marker 'sees' a ground through the turn signal filaments. They will light but they don't draw enough power to light the larger filaments. Possibly if you took the red or amber lenses off you might see a very slight glow on the filament but not enough to see.

In order for the side markers to flash they would have to be on in the first place. I guess an ignition switched relay to turn the parking/marker/license lamps on would work.

Post by **Three B's Racing** » 05 Mar 2021 06:10

If you aren't you should be? Let me think for a second,,,,,,,,,,,,,,,,Hehehehehehehe, Hahahahaha! Sounds like you should be so don't lay that on us.

Post by **Stu** » 05 Mar 2021 10:27

datzenmike wrote: ↑04 Mar 2021 11:47 Occam's razor.... The simplest solution is probably the best. Drive with your headlamps on. If you aren't you should be. We can all agree that today's drivers are for the most part incompetent. If you are under 50 you may have some impairment too. I mean no disrespect but newer drivers relay too heavily on their vehicles to save them. They look down the road at an intersection and if they don't see headlights, think all is clear. Most cars have daytime running lights and a Datsun should too. Not to see but to be seen by other drivers. I always run with my HIDs on.

I am planning on running my parking/headlights on relays and the main light switch on the 'ACC' portion of the electrical so that I can just leave the headlight switch on, but have them turn off when I start the car or when it is turned off. I don't have a buzzer in my car so this is the safest way to keep me from leaving my lights on and draining the battery.

I got some feedback on my question posed on FB and people said that the side marker will blink/illuminate even when the lights are off. But because this modification uses grounding through a filament, it will not work with LED bulbs since they will not back flow current. I am not currently planning on using LEDs, but may in the future. I ended up buying "Blinker Genie 2" from https://www.customled.com/. It uses a mosfet/transistor system to control any 'two wire' bulb using 'three wire control' (ground is considered a wire). It uses input from parking and turn signal to send power to the side marker. The grounds stay as is for the bulbs. This will allow me to use incandescent or LED in the future and does not rely on grounding through other components (the marker light housing does not need to be isolated either). They are pretty small and should just blend into the wiring with some new connectors.

The 510 Realm