Converting "turn blinkers" to "indicators + turn blinkers"

[gr_diver]

Hello my friends once again!

My car has two 4W "parking lights", one on each of the front wings (See photo). It has always been my plan to convert them to turn repeaters, and today I located a pair of amber lenses for them. This conversion is pretty straighforward to do, with such low wattage just splicing them in the turn signal cabling would do it. Though something new crossed my mind.

I'd like to have them both as indicators, switching on with the front and rear marker lights, but still have them operate as turn repeaters. I've seen this on many cars.

Does anybody have a circuit diagram to help me with this mod? I can't figure it out on my own...

Thank you in advance...

[jlthunder]

During the 70's, 80's and '90's most GM cars in the U.S.performed this function. When the parking/headlights were off, the side marker(repeater) blinked with the indicator. When the parking/headlights were on, they burned steady and then alternated with the turnsignal(turn signal on, repeater off & turn signal in the off mode of blink, repeater on).

If your bulb only has one wire going to it, you are out of luck. If you have 2 wires, you may be able to rewire it. I traced the wires on my S-10 once and noticed that one wire went to the + turn signal wire and the other went to the + wire of the parking light. NO GROUND WIRE. I don't know how this works but it did. Others here would be able to explain it to you.

Here is a list of cars which I owned which performed this feature

'75-'79 Chevrolet Nova
'78-'81 Chevrolet Camaro
'75-'92 Chevrolet Caprice
'82'-01 Chevorlet S-10 Pick-up and Blazer.

The current 2006 C-1500 Chevrolet Pick up does it on the front and rear tailights.

See if you can get any wiring diragrams.

HTH
Jeff

[hallgeir]

If your bulb only has one wire going to it, you are out of luck. If you have 2 wires, you may be able to rewire it. I traced the wires on my S-10 once and noticed that one wire went to the + turn signal wire and the other went to the + wire of the parking light. NO GROUND WIRE. I don't know how this works but it did. Others here would be able to explain it to you.


HTH
Jeff

Ok, I`ll try. When the parking light is on you have +12v at the parking light wire connected to the bulb, and 0v at the wire from the turn signal relay. When you switch on the turn signal, there will be +12v at both wires, and the lamp will not light. This will alternate with the turn signal (+12v - no light, 0v - light). If the parking light is off, there is 0v at the wire from the parking light, and when you turn on the turn signal, the bulb will light up when it gets +12v from the turn signal wire.
Hope this helps.

[gr_diver]

Thank you very much for your responses!!!

The bulbs have only 1 wire going to them (+12V), and they are grounded via the metal support/frame, of the tiny indicator. So, it is not possible to do this by plain rewiring...

I found some schematics at some motorcycle pages, that perform this function on add-on driving lights, but it is far too complicated, with 2 relays for each side, diodes and more that I don't recall...


So I will leave this advanced side of the project. Having side turn repeaters, by itself, will be a nice touch, and a practicall issue! Many times I have realized that other drivers at cross-roads were trying to guess which way I will be going, because I didn't have side repeaters... Well now I do!

Cheers

[2 Fast 4 U]

Here is a little drawing that uses 3 relay's to make it work:

[gr_diver]

Thanks Erick, I will study it tomorrow, and if it is doable and worth the effort I'll give it a shot!

[gr_diver]

Bringing back an old topic. I was thinking again of this modification, and extensively studied the schematic 2 Fast 4 U kindly provided me with.

I thought of this simple 1 relay per side circuit that I think would yield the same effect.

Connections: The relay will be powered from a +12V constant source, so indicators/hazards will work regardless of ignition status, on terminal 87 (N/O). The cables from turn signals and indicators will be the triggers of the relay, terminals 85 & 86. Finally the bulb will be connected to terminal 30 (common), and grounded via the chassis, as it is from the factory.

Operation: When either blinkers or indicators have power, the relay will be triggered and the bulb will light. With the indicator lights off, the side blinker will operate in sync with the front/rear blinkers. With the indicator lights on, if the turn signal gets activated, the opposing currents on the relay's coil will neutralize it, thus blinking the side bulb in reverse polarity from the front/rear blinkers.

To be short, I "apply" the supposed 2-wire socket's connections to a relay, which provides current from another source. Even in stock 2-wire side blinkers/indicators, the side blinkers operate in reverse polarity from the front/rear blinkers when the parking/marker lights are on, because the fronts/rears have dual filament bulbs, vs. single filament bulbs at the sides.

I don't know though if it is allowed to have opposed currents in a relay's coil. I have never attempted it, and this is my main worry.

Do you guys think it might work? I am asking for confirmation because it would be a shame to cut and splice cables, only to find out that I hadn't thought of something...

Thank you!

Antonis

[heimue]

There is a circuit for sale for around 20 or 25 Euro per pair in Germany, to combine marker lights and indicator lights. It has two 12V inputs for the marker and indicator, and you connect one single filament 21W bulb to it. When the marker is on, the bulb just glows like a 5W marker bulb, and when the indicator comes on it flashes with full 21W brightness. I have a contact telephone and/or email at home, and will post it tomorrow.

Dieter

[gr_diver]

Thanks Dieter for your reply!

The kit you mention though, is for front 21W blinkers. I want to do this to the tiny 4W bulbs my car has at the front wings. They used to be parking lights, but I have converted them to blinkers.

[oldopelguy]

I don't know though if it is allowed to have opposed currents in a relay's coil. I have never attempted it, and this is my main worry.

This circuit should work fine, but you may have to carefully select your relay before you hook it up. Some relays incorporate a diode inside them to allow the current induced by the collapsing magnetic field of the coil to circulate freely within the relay itself instead of trying to back feed to the control circuit. Usually these have the universal symbol for a diode on them somewhere, which is a triangle with a line across one of the tips (▼), but aside from that I don't know how to spot one by part #. If you tried to hook one of these up it would look like a short to the circuit in one direction (and the relay would not work that direction) which might make for worrisome trouble-shooting and could damage some circuits. Your best bet might be an electronics supply store, one where you can specify no diode when you buy it and be sure it won't have one.

[markandson]

If you want to test for a diode it is very easy to do with a meter, or for that matter a battery and a light bulb. If you can hook it so that plus and minus can be reversed and you still get current flow (light bulb lit) then there is no diode.

[gr_diver]

Thank you for your replies!

I was away since Friday, now that I am back I will test the idea and post any results!

[baz]

could you not run 2 wires to the repeater with diodes inline so no back voltage goes to the other circuit ? and join them to the 1 feed wire going in

this is how i have converted my indicators in my van from 2 marker bulbs in the dash to 1 marker with the new dash

the voltage can not effect the other side as both would go to ground through th bulb and easier than relays all over the place

they need to be heavy duty items but easy to find , mine came out of phone sockets

[gr_diver]

baz: wouldn't your recommendation make the side repeaters work as turn signals only during day-time? If at night there is constant +12V from the marker-lights, the +12V from the turn-signals would do nothing... So at night they will only work as marker lights.

Anyway, I tried my idea and it works as I thought it would. It is still daytime here, so I have to wait till it gets dark to verify that it is 100% ok. My worry is that maybe there is back voltage from the turn-signals to the markers or vice-versa, and because of sun-light I might not be able to see the bulbs being on ever so slightly. I don't think it is likely, but I have to check... Thanks to my custom made power distribution blocks, installation was a 30 minutes job, including removing and refitting the underside of the dash to expose the fusepanel / wiring. If anything is wrong, it is a matter of disconnecting male/female crimp-on connectors to go back.

[tekenaar]

Bringing back an old topic. I was thinking again of this modification, . . . .

I thought of this simple 1 relay per side circuit that I think would yield the same effect.

Connections: The relay will be powered from a +12V constant source, so indicators/hazards will work regardless of ignition status, on terminal 87 (N/O). The cables from turn signals and indicators will be the triggers of the relay, terminals 85 & 86. Finally the bulb will be connected to terminal 30 (common), and grounded via the chassis, as it is from the factory.

Operation: . . .

I don't know though if it is allowed to have opposed currents in a relay's coil. I have never attempted it, and this is my main worry.

Do you guys think it might work? ...

Thank you!

Antonis

First, the correct (TÜV) wiring of any automotive SPDT relay always uses terminal 30 (COMMON) contact as the voltage source, while "87" contact is always the "NO" load and "87a" contact is always the "NC" load. That's why all automotive relay terminals are numbered like this . . . it's an automotive "Standard"!

Look at any German wiring diagram, so just swap your "30" and "87" connections.

Second, there's no problem with swapping "poles" (plus/minus) on a relay's coil. As an example, the TÜV certified method of wiring Fog Lights uses this method. Fog lights are only allowed to be "ON" either with "parking lights" or "low beams" and must be "OFF" with "high beams", like this:

[tekenaar]

This circuit should work fine, but you may have to carefully select your relay before you hook it up. Some relays incorporate a diode inside them to allow the current induced by the collapsing magnetic field of the coil to circulate freely within the relay itself instead of trying to back feed to the control circuit. Usually these have the universal symbol for a diode on them somewhere, which is a triangle with a line across one of the tips (▼), but aside from that I don't know how to spot one by part #. If you tried to hook one of these up it would look like a short to the circuit in one direction (and the relay would not work that direction) which might make for worrisome trouble-shooting and could damage some circuits. Your best bet might be an electronics supply store, one where you can specify no diode when you buy it and be sure it won't have one.

Actually, you'd have to specify one WITH a diode, as they're the rarity . . . usually a diode is added to the relay plug when needed - my original OttoStart, for example - rather than relay itself! A "fused" SPST relay is much more commonly used than a "reverse current diode (coil)" relay.

[gr_diver]

First, the correct (TÜV) wiring of any automotive SPDT relay always uses terminal 30 (COMMON) contact as the voltage source, while "87" contact is always the "NO" load and "87a" contact is always the "NC" load. That's why all automotive relay terminals are numbered like this . . . it's an automotive "Standard"!

You are totally right Otto, the day I was thinking about the modification I had made several sketches, and most of them were using the relay to alternatively switch two power sources to one bulb, that's why I had the bulb on "common". Today during wiring I did it the correct way, since there is only 1 power source (the constantly live +12V). I like following the standards. I even (always) stick to the German cable color coding (red for constantly live +12V, yellow for ignition switched +12V and brown for grounds). It's nice to have all wiring look stock, and have a pattern. It also makes troubleshooting easier.

The circuit works flawlessly and the car looks absolutely beautiful! The mod gave a "luxury car" appearance. In the photo it does not look as nice as it does in reality...

[heimue]

The kit you mention though, is for front 21W blinkers. I want to do this to the tiny 4W bulbs my car has at the front wings. They used to be parking lights, but I have converted them to blinkers.

Put a bigger bulb in, that cures all your problems.
Anyway, a little late since I'm not the youngest anymore and my friends start calling me "harebrain", here is the contact for where you get the mentioned circuit: email ffo2002"at"freenet.de, or phone in Germany (+49) (171) 5284184.

Dieter