I know it can be done.. - The 1947 - Present Chevrolet & GMC Truck Message Board Network

magnethead · 10-03-2006, 09:22 PM

How can I make my fender lights flash with my turn signals like an 18 wheeler? Surely the 2 sets on each side use a different wire for each frame rail, or do they go across the cross-rail with the fuel lines? I know I'd have to have the relay set with turn signal on the trigger side and the wire to the markers on the output side, but what number ports are they and what size relay would I need? To make it work during the day, wouldn't I have to make the wire from the cab become a constant feed instead of a switched lead? Anything I should know about, legality wise or electrical wise?

And I haven't looked, are the markers on the front lighted or reflection only?

lurch115 · 10-03-2006, 09:56 PM

wire them in with the turn signal wiring

magnethead · 10-03-2006, 11:32 PM

Quote:

Originally Posted by lurch115

wire them in with the turn signal wiring

that was my thought, but would the fuse box relay be strong enough to power all 5 bulbs plus 1 more on a trailer (we do tow with it) for each turn direction? I figure it would require an external SPST relay for each side? Or could I get away with using a single DPDT in some way? It'd be nice if the factory wiring was split going down each frame rail to the cab so I could just mount a DPDT to the firewall and only have a few short wiring runs.

mhicks · 10-04-2006, 01:20 PM

I have a '73 and my front side lights do flash with the blinkers.

magnethead · 10-04-2006, 04:51 PM

Quote:

Originally Posted by mhicks

I have a '73 and my front side lights do flash with the blinkers.

I don't think mine do....

question still stands- would the main flasher relay be strong enough to run 6 lights at once without slowing down (if not more, depending on how many lights are on trailer)?

84 400 · 10-04-2006, 05:25 PM

so you want all the fender lights to be able to flash right? the ones on the box and the front two? I think it can be done easly and i would think it should hhave enough power but i have never done it

magnethead · 10-04-2006, 07:20 PM

I'll trace the wires and just do a demo to see how it works within the week, then decide from there wether to relay it or not.. looks like 2 SPST's or a single DPDT should do the job, I can't see the lights being much more than 10 amps?

magnethead · 10-04-2006, 10:01 PM

nope, all my markers are solid state..only the 4 corners flash.

**N2TRUX** · 10-04-2006, 11:54 PM

Put in a heavy duty flasher relay and wire them to your turn signals.

magnethead · 10-05-2006, 08:27 AM

Quote:

Originally Posted by N2TRUX

Put in a heavy duty flasher relay and wire them to your turn signals.

define heavy duty? How do i know what relay I have now? This has been a racecar hauler most of it's life, so I wouldn't know what it has.

magnethead · 10-07-2006, 09:12 AM

So I went and looked at it, the side front markers have 2 wires going to them and the front turn signals have 3. I can find the pos lead of the marker myself, but which wire to the signal is the flashing wire, and why is there three? Does it get a 9 volt current from the marker system and 12 from the flasher, so it doesn't fully dim? How do I rig that up, hook the pos wire of the marker to both of the other wires?

How will I do the rears, in a similar system? Keep the existing wire connected to the marker system and install a jumper from the signal wire of the tailights to the marker lights?

boxrodz · 10-09-2006, 02:36 AM

The front parking/directional lights have a two filament bulb hence the three wires. One wire (Black) is ground, another one wire is for the parking filament and the other one is for the directional filament. You would spice one wire of the 2-wire (single filament) side marker into the parking light wire and the other wire into the directional wire. If spiced correctly, when the signals are activated the side marker should blink in sequence with the front directional light. When the parking lights are switched on, the side marker should light. Then, when the signals are activated with the parking lights switched on, the side markers should blink alternating (not in sequence) with the front directional light. The rear side markers should be wire similar to the front. Just find the parking light wire and the directional light wire and spice into them.

magnethead · 10-10-2006, 06:30 PM

the markers are already on the parking wire, so I just need a jumper between directional (turn) and the marker wire right?

boxrodz · 10-11-2006, 12:17 AM

Yeah, just make sure you sever the side marker's ground connection before spicing it into directional wire.

magnethead · 10-11-2006, 08:04 AM

what for? If there's no ground, it can't light up at all?????

magnethead · 10-12-2006, 07:18 PM

any other input?

boxrodz · 10-12-2006, 11:38 PM

Quote:

Originally Posted by magnethead

what for? If there's no ground, it can't light up at all?????

I'm not certain if your wiring is different than that on a '83, but the potential (voltage) difference between the front parking lights and the front directional signals causes the side markers to light based on what I posted earlier. The side markers do not require it's own isolated ground, since it maintains a close loop between the parking lights and directional signals which shares the ground.

Take a 194 bulb and attach a couple of leads to the bulb's terminals. Then, attach the end of one lead to the directional signal and the end of the other lead to the parking light. Hit the lights and try the signal and see if the bulb lites ...

magnethead · 10-14-2006, 11:33 AM

parking lights are 9V and directional are 12V I take it? I'd have to recheck mine, but i'm pretty sure i measured 11 or 12 volts at all my #194 sockets with engine off. Maybe only the 4 corner parking light wires are reduced voltage?

boxrodz · 10-18-2006, 02:54 PM

Nah. You should have nominally 12 volts at all your lights (parking and directional). It is the change of voltage between 0 (off) and 12V (on) on the parking lights and/or the change of voltage between 0 and 12V (blinking) on the signal lights that would cause your sidemarkers to follow suit.

magnethead · 10-18-2006, 10:03 PM

So how do the dual-element bulbs flash with the lights on? Being markers, the side lights have to stay at least half bright when the turn signals are engaged, then return to full bright with signals off.

magnethead · 11-09-2006, 08:27 PM

don't want to resurrect an old thread of mine, but i'm working on this during my thanksgiving break, and I think I just made sense of it..

194 bulbs are uni-directional...
with the parking wire on one lead (+) and the directional on the other (-), the parking wire flows from + to -, grounding through the directional circuit, and when both are turned on, the current flows from directional (-) to parking (+), grounding through the parking circuit.

Is that right? Or something to that effect?

Bad71chev406sbc · 11-10-2006, 01:59 AM

I know that you can wire them up to flash alternately of the turnsignals.....meaning......turn signal on, off while marker on, off while signal is on....i did it to my ranger...and my chevy. That's a way you can have those markers be your running lights, and flash for a signal.

boxrodz · 11-10-2006, 04:25 AM

Quote:

Originally Posted by magnethead

don't want to resurrect an old thread of mine, but i'm working on this during my thanksgiving break, and I think I just made sense of it..

194 bulbs are uni-directional...
with the parking wire on one lead (+) and the directional on the other (-), the parking wire flows from + to -, grounding through the directional circuit, and when both are turned on, the current flows from directional (-) to parking (+), grounding through the parking circuit.

Is that right? Or something to that effect?

You're close...

The 194s are not necessarily considered uni-directional, but rather considered single filament bulbs. (Whereas the 1157s are dual filament bulbs; one filament dedicated to the parking light circuit and the other filament dedicated to the directional signal circuit.) Since we're talking a DC (direct current) system, current flows only in one direction from the Source (12V) to Ground (0V) or from + to - in your analogy (but not from - to +).

Your thinking of the common ground for the parking lights and the directional lights is accurate. But, I think of the operation in this way:

Connect one terminal of the 194 to the 'Source' wire of the parking light terminal (where the other terminal of the parking light is common Ground.) Then connect the other terminal of the 194 to the Source wire of the directional light terminal (where the other terminal of the directional light is common Ground.)

When the parking lights are switched on with the directional signals off, the Source wire for the parking light applies 12V to one terminal of the 194 with the other terminal of the 194 (tied to the Source wire for the directional light) is at 0V (since the directional signals are off). With a voltage drop of 12V across the 194, the 194 lights up. Hence, the side markers light up when the parking lights are switched on.

When the parking lights are off and the directional signals flashing on, the Source wire for the directional light applies 12V to one terminal of the 194 with the other terminal of the 194 (tied to the Source wire for the parking light) is at 0V (since the parking lights are off). With a voltage drop of 12V across the 194, the 194 lights up. The moment the directional signal flashes off, the Source wire for the directional light tied to one terminal of the 194 is now at 0V (with the other terminal of the 194 tied to the Source wire for the parking light is still at 0V). With a voltage drop of 0V across the 194, the 194 is off. Hence, the side markers flash in sequence with the front signals.

When the parking lights on and the directional signals flashing on, the Source wire for the parking light applies 12V to one terminal of the 194 while the Source wire for the directional light applies 12V to the other terminal of the 194. Effectively, with no voltage drop across the 194, the 194 is off. The moment the directional signal flashes off, the Source wire for the directional light tied to one terminal of the 194 is now at 0V (with the other terminal of the 194 tied to the Source wire for the parking light is still at 12V). With a voltage drop of 12V across the 194, the 194 lights up. Hence, the side markers flash alternately to the front signals.

Hope this helps.

magnethead · 11-10-2006, 07:24 PM

Is this right then?

magnethead · 11-11-2006, 09:32 AM

playing with my DMM last night, is it true that the marker circuit grounds out when the switch is pushed back to the off position? I turned them on to make sure the bulb lit, then popped the bulb out and turned the circuit off, both terminals had 0 resistance to ground. I couldn't get a probe on the turn signal wire to see if it does the same thing, does it?

If so, i might tackle that project on the 20th unless i can get to the passenger side wires without moving the battery (then i'll do it today).

10-03-2006, 09:56 PM	#2
lurch115 Registered User Join Date: Oct 2006 Location: iowa Posts: 722	Re: I know it can be done.. wire them in with the turn signal wiring

10-04-2006, 01:20 PM	#4
mhicks Registered User Join Date: Jan 2004 Location: Weatherford,Tx Posts: 747	Re: I know it can be done.. I have a '73 and my front side lights do flash with the blinkers.

10-04-2006, 05:25 PM	#6
84 400 Sb 400 club Join Date: Nov 2005 Location: NH / MA Posts: 2,746	Re: I know it can be done.. so you want all the fender lights to be able to flash right? the ones on the box and the front two? I think it can be done easly and i would think it should hhave enough power but i have never done it __________________ 1984 chevy c10, built 400sb,.(SOLD) 77 K10 Project / daily driver "The Grinch" http://67-72chevytrucks.com/vboard/s...d.php?t=318363 1956 Willys Wagon (327 chevy) Project (Now Buick 225) 1980 Corvette L-48 4 speed 1992 Mustang GT built 5.0 5 speed 1985 C10 LWB Sold 1982 K10 SWB plow truck Parted out 1986 D30 M1028 fire brush truck Parted out

10-04-2006, 07:20 PM	#7
magnethead 7000 #'s of american IRON Join Date: Dec 2004 Location: north tx Posts: 883	Re: I know it can be done.. I'll trace the wires and just do a demo to see how it works within the week, then decide from there wether to relay it or not.. looks like 2 SPST's or a single DPDT should do the job, I can't see the lights being much more than 10 amps?

10-04-2006, 10:01 PM	#8
magnethead 7000 #'s of american IRON Join Date: Dec 2004 Location: north tx Posts: 883	Re: I know it can be done.. nope, all my markers are solid state..only the 4 corners flash.

10-03-2006, 09:22 PM	#1
magnethead 7000 #'s of american IRON Join Date: Dec 2004 Location: north tx Posts: 883	I know it can be done.. How can I make my fender lights flash with my turn signals like an 18 wheeler? Surely the 2 sets on each side use a different wire for each frame rail, or do they go across the cross-rail with the fuel lines? I know I'd have to have the relay set with turn signal on the trigger side and the wire to the markers on the output side, but what number ports are they and what size relay would I need? To make it work during the day, wouldn't I have to make the wire from the cab become a constant feed instead of a switched lead? Anything I should know about, legality wise or electrical wise? And I haven't looked, are the markers on the front lighted or reflection only?

10-04-2006, 11:54 PM	#9
N2TRUX Happy to be here Join Date: Mar 2000 Location: Cypress, TX Posts: 39,021	Re: I know it can be done.. Put in a heavy duty flasher relay and wire them to your turn signals. __________________ Follow me on Facebook and Instagram @N2trux.com Articles- "Jake" the 84 to 74 crewcab "Elwood" the77_Remix 85 GMC Sierra "Scarlett" "Refining Sierra"

10-07-2006, 09:12 AM	#11
magnethead 7000 #'s of american IRON Join Date: Dec 2004 Location: north tx Posts: 883	Re: I know it can be done.. So I went and looked at it, the side front markers have 2 wires going to them and the front turn signals have 3. I can find the pos lead of the marker myself, but which wire to the signal is the flashing wire, and why is there three? Does it get a 9 volt current from the marker system and 12 from the flasher, so it doesn't fully dim? How do I rig that up, hook the pos wire of the marker to both of the other wires? How will I do the rears, in a similar system? Keep the existing wire connected to the marker system and install a jumper from the signal wire of the tailights to the marker lights? Last edited by magnethead; 10-07-2006 at 09:13 AM.

10-09-2006, 02:36 AM	#12
boxrodz Until Seventy Times Seven Join Date: Feb 2005 Location: Rocky Mountain Front Range Posts: 1,301	Re: I know it can be done.. The front parking/directional lights have a two filament bulb hence the three wires. One wire (Black) is ground, another one wire is for the parking filament and the other one is for the directional filament. You would spice one wire of the 2-wire (single filament) side marker into the parking light wire and the other wire into the directional wire. If spiced correctly, when the signals are activated the side marker should blink in sequence with the front directional light. When the parking lights are switched on, the side marker should light. Then, when the signals are activated with the parking lights switched on, the side markers should blink alternating (not in sequence) with the front directional light. The rear side markers should be wire similar to the front. Just find the parking light wire and the directional light wire and spice into them. __________________ boxRODz 1983 C10 SWB Fleetside When two halves is gone, there's nuthin left. Two nothings is nuthin. That's mathematics son. You can argue with me but you can't argue with figures. Two half nothings is a whole nuthin... Last edited by boxrodz; 10-09-2006 at 02:37 AM.

10-10-2006, 06:30 PM	#13
magnethead 7000 #'s of american IRON Join Date: Dec 2004 Location: north tx Posts: 883	Re: I know it can be done.. the markers are already on the parking wire, so I just need a jumper between directional (turn) and the marker wire right?

10-11-2006, 12:17 AM	#14
boxrodz Until Seventy Times Seven Join Date: Feb 2005 Location: Rocky Mountain Front Range Posts: 1,301	Re: I know it can be done.. Yeah, just make sure you sever the side marker's ground connection before spicing it into directional wire. __________________ boxRODz 1983 C10 SWB Fleetside When two halves is gone, there's nuthin left. Two nothings is nuthin. That's mathematics son. You can argue with me but you can't argue with figures. Two half nothings is a whole nuthin...

10-11-2006, 08:04 AM	#15
magnethead 7000 #'s of american IRON Join Date: Dec 2004 Location: north tx Posts: 883	Re: I know it can be done.. what for? If there's no ground, it can't light up at all?????

10-12-2006, 07:18 PM	#16
magnethead 7000 #'s of american IRON Join Date: Dec 2004 Location: north tx Posts: 883	Re: I know it can be done.. any other input?

10-14-2006, 11:33 AM	#18
magnethead 7000 #'s of american IRON Join Date: Dec 2004 Location: north tx Posts: 883	Re: I know it can be done.. parking lights are 9V and directional are 12V I take it? I'd have to recheck mine, but i'm pretty sure i measured 11 or 12 volts at all my #194 sockets with engine off. Maybe only the 4 corner parking light wires are reduced voltage?

10-18-2006, 02:54 PM	#19
boxrodz Until Seventy Times Seven Join Date: Feb 2005 Location: Rocky Mountain Front Range Posts: 1,301	Re: I know it can be done.. Nah. You should have nominally 12 volts at all your lights (parking and directional). It is the change of voltage between 0 (off) and 12V (on) on the parking lights and/or the change of voltage between 0 and 12V (blinking) on the signal lights that would cause your sidemarkers to follow suit. __________________ boxRODz 1983 C10 SWB Fleetside When two halves is gone, there's nuthin left. Two nothings is nuthin. That's mathematics son. You can argue with me but you can't argue with figures. Two half nothings is a whole nuthin...



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10-18-2006, 10:03 PM	#20
magnethead 7000 #'s of american IRON Join Date: Dec 2004 Location: north tx Posts: 883	Re: I know it can be done.. So how do the dual-element bulbs flash with the lights on? Being markers, the side lights have to stay at least half bright when the turn signals are engaged, then return to full bright with signals off.

11-09-2006, 08:27 PM	#21
magnethead 7000 #'s of american IRON Join Date: Dec 2004 Location: north tx Posts: 883	Re: I know it can be done.. don't want to resurrect an old thread of mine, but i'm working on this during my thanksgiving break, and I think I just made sense of it.. 194 bulbs are uni-directional... with the parking wire on one lead (+) and the directional on the other (-), the parking wire flows from + to -, grounding through the directional circuit, and when both are turned on, the current flows from directional (-) to parking (+), grounding through the parking circuit. Is that right? Or something to that effect? Last edited by magnethead; 11-09-2006 at 08:28 PM.

11-10-2006, 01:59 AM	#22
Bad71chev406sbc Registered User Join Date: Nov 2006 Location: Boring, Oregon Posts: 162	Re: I know it can be done.. I know that you can wire them up to flash alternately of the turnsignals.....meaning......turn signal on, off while marker on, off while signal is on....i did it to my ranger...and my chevy. That's a way you can have those markers be your running lights, and flash for a signal. __________________ '71 SNB, 406sbc, TH350 w/ Transpak & Starshifter, 12bolt w/ 3.73s, 2" Early Classic front coils, 2.5" Flowmaster Super 40's

11-10-2006, 07:24 PM	#24
magnethead 7000 #'s of american IRON Join Date: Dec 2004 Location: north tx Posts: 883	Re: I know it can be done.. Is this right then? Attached Images

11-11-2006, 09:32 AM	#25
magnethead 7000 #'s of american IRON Join Date: Dec 2004 Location: north tx Posts: 883	Re: I know it can be done.. playing with my DMM last night, is it true that the marker circuit grounds out when the switch is pushed back to the off position? I turned them on to make sure the bulb lit, then popped the bulb out and turned the circuit off, both terminals had 0 resistance to ground. I couldn't get a probe on the turn signal wire to see if it does the same thing, does it? If so, i might tackle that project on the 20th unless i can get to the passenger side wires without moving the battery (then i'll do it today).

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