Author Topic: side lights flash with indicators ( LED)  (Read 13144 times)

Offline impco lpg

  • Newbie
  • Posts: 98
  • Newbie
side lights flash with indicators ( LED)
« on: September 10, 2017, 10:03:58 AM »
hi all,
I have replaced all my lights units to LED (NOT THE BULBS)  front and rear. when i just turn on my indicators or hazards, the front and rear side lights flash at the same time.  but not at full power (side lights only), is this an earth fault or do I need a resistor flasher unit. FRONT MARKERS ARE BULBS.
any help would be appreciated THANKS


1985 chevy c10 stepside 5.7  2wd
« Last Edit: September 10, 2017, 10:48:03 AM by impco lpg »
1983 cucv m1009  blazer 6.2 4x4
1991 1500 suburban 5.7 4x4 lpg
2003 dodge ram 5.7 4x4 lpg
1985 chevy c10 stepside  2wd 5.7ltr 350 lpg

Online bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 6438
Re: side lights flash with indicators ( LED)
« Reply #1 on: September 10, 2017, 10:19:36 PM »
The front side markers are supposed to flash with the turn signals, but they should flash at normal brightness, not dimly.  To restore proper function read on.

The factory front side markers are wired BETWEEN the forward turn light filament and forward park light filament power feeds.  The side markers do not use a conventional ground, but instead ground THROUGH the front turn or park filaments that aren't powered at the time.  The factory configuration works, because the side marker bulbs (194) require only a fraction of the current necessary to illuminate the park and turn filaments of the forward turn/park lamp bulbs (1157).  Essentially, you've introduced high resistance grounds for the side marker lamps by substituting the LED lamps for conventional filament bulbs.  The side marker filaments require more current to illuminate than will pass through the LED lamps to ground. 

Installing a 10 Ω, 25 watt to 20 Ω, 15 watt resistor on both sides of each side marker lamp to ground should solve the problem - something along the line of these.  Using resistors with greater wattage ratings (up to ~50 watts) won’t detract from the resistors’ function, BUT avoid using resistors with lower wattage ratings than specified above or they will overheat.  You will need four resistors to complete the task.
« Last Edit: September 10, 2017, 10:43:30 PM by bd »
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline impco lpg

  • Newbie
  • Posts: 98
  • Newbie
Re: side lights flash with indicators ( LED)
« Reply #2 on: September 12, 2017, 01:58:18 PM »
thanks for your reply.
as I live in the uk the previous owner has altered the front wiring. so that you do not have amber front markers, they only come on when you indicate pic two. there was a white front bulb 194 in the top headlight. so am I right in thinking I need to revert back to standard as factory first ?
I have some pics. is this standard wiring colours and connectors  to a 1985 c10 ? (there is one at each side)
the last pic shows two black wires that come from the side marker (drivers side) ln to light blue and green not as factory I think ?
the first pic shows a junction box on drivers side inner fender, there are two light green wires that have been cut that go into a relay.

HELP :(
« Last Edit: September 12, 2017, 02:03:52 PM by impco lpg »
1983 cucv m1009  blazer 6.2 4x4
1991 1500 suburban 5.7 4x4 lpg
2003 dodge ram 5.7 4x4 lpg
1985 chevy c10 stepside  2wd 5.7ltr 350 lpg

Online bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 6438
Re: side lights flash with indicators ( LED)
« Reply #3 on: September 12, 2017, 03:37:36 PM »
Reverting to the factory wiring would be a solid move.  Neither the white junction box nor any of the white connectors are original to a U.S. built truck.  As to the wire colors, GM uses those colors in the forward lamp wiring, but since it isn't original I cannot speak to whether the colors tie directly to the original color scheme.  Refer to the 1985 Wiring Manual to help sort it out.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline impco lpg

  • Newbie
  • Posts: 98
  • Newbie
Re: side lights flash with indicators ( LED)
« Reply #4 on: September 14, 2017, 11:38:53 AM »
ok  I let you know how I get on cheers neil
1983 cucv m1009  blazer 6.2 4x4
1991 1500 suburban 5.7 4x4 lpg
2003 dodge ram 5.7 4x4 lpg
1985 chevy c10 stepside  2wd 5.7ltr 350 lpg

Offline impco lpg

  • Newbie
  • Posts: 98
  • Newbie
Re: side lights flash with indicators ( LED)
« Reply #5 on: September 18, 2017, 01:17:35 PM »
update, I have reverted back to factory at the front wire loom. everything is working as it should (front markers and side markers amber) and both indicate as they should. the relay with the two green wires that were cut turned out to be for the high beam. the back lights work fine indicating left or right only, BUT when I put the hazards on the red tail lights still flash with the indicators,  I have a video of the problem. is this still a ground fault ? or do I still need a resistor/s ?

YouTube video link
https://www.youtube.com/watch?v=8_4omd6rkZk
« Last Edit: September 22, 2017, 02:58:55 PM by impco lpg »
1983 cucv m1009  blazer 6.2 4x4
1991 1500 suburban 5.7 4x4 lpg
2003 dodge ram 5.7 4x4 lpg
1985 chevy c10 stepside  2wd 5.7ltr 350 lpg

Online bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 6438
Re: side lights flash with indicators ( LED)
« Reply #6 on: September 21, 2017, 12:04:50 PM »
Your custom installation needs clarification.  Are the inboard pencil lamps you installed upper half amber, lower half red?  How many wires connect to the inboard pencil lamps and how are they wired with regard to brake/turn/tail/backup?  How about the outboard pencil lamps - what is their color and function and how are they wired with regard to brake/turn/tail/backup?  In other words, what are you trying to accomplish with the various lamps and exactly how did you wire them?  Since it is a custom installation, you need to be explicit.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline impco lpg

  • Newbie
  • Posts: 98
  • Newbie
Re: side lights flash with indicators ( LED)
« Reply #7 on: September 22, 2017, 02:54:56 PM »
the rear pencil lights are upper amber and lower red. (uk spec)
there are 4 wires per pencil light lh/rh. the RED is for brake and tail ONLY as per (pic 1),  the amber is for turn right/left and hazard ONLY.
the backup is the outer x6 led light.

all the rear lights wires are in a 10 way junction box at rear of pickup (pic 2) the wires to the right of box come from the white junction
box (front fender) there are 7 wires. blu is tail, red is indicator lh, yel is side lights, wht is earth, brn is stop, blk is indicator rh, grn is backup. there are two bulk head connectors (pic 3) as per factory ? right is rear lights left is front lights ? there are 4 wires coming from the right connector dk grn, lt grn, brn, yel. which go into white connector (pic 4) they connect to the rear loom. dk grn = blk, lt grn =yel and grn, brn =blu, yel =red

pencil light wire colours
red is stop
wht is earth
brn is tail
yel is indicator lh/rh

this sounds a little confusing but there is something not right, any help would be most appreciated regards neil
1983 cucv m1009  blazer 6.2 4x4
1991 1500 suburban 5.7 4x4 lpg
2003 dodge ram 5.7 4x4 lpg
1985 chevy c10 stepside  2wd 5.7ltr 350 lpg

Offline impco lpg

  • Newbie
  • Posts: 98
  • Newbie
Re: side lights flash with indicators ( LED)
« Reply #8 on: September 22, 2017, 02:57:00 PM »
update, I have reverted back to factory at the front wire loom. everything is working as it should (front markers and side markers amber) and both indicate as they should. the relay with the two green wires that were cut turned out to be for the high beam. the back lights work fine indicating left or right only, BUT when I put the hazards on the red tail lights still flash with the indicators.  I have a video of the problem. is this still a ground fault ? or do I still need a resistor/s ?

YouTube video link:
https://www.youtube.com/watch?v=8_4omd6rkZk
1983 cucv m1009  blazer 6.2 4x4
1991 1500 suburban 5.7 4x4 lpg
2003 dodge ram 5.7 4x4 lpg
1985 chevy c10 stepside  2wd 5.7ltr 350 lpg

Online bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 6438
Re: side lights flash with indicators ( LED)
« Reply #9 on: September 22, 2017, 06:17:25 PM »
the rear pencil lights are upper amber and lower red. (uk spec)
there are 4 wires per pencil light lh/rh.  the RED is for brake and tail ONLY as per (pic 1),  the amber is for turn right/left and hazard ONLY.
the backup is the outer x6 led light.

all the rear lights wires are in a 10 way junction box at rear of pickup (pic 2) the wires to the right of box come from the white junction
box (front fender) there are 7 wires: blu is tail, red is indicator lh, yel is side lights, wht is earth, brn is stop, blk is indicator rh, grn is backup. there are two bulk head connectors (pic 3) as per factory ? right is rear lights left is front lights ? there are 4 wires coming from the right connector dk grn, lt grn, brn, yel. which go into white connector (pic 4) they connect to the rear loom. dk grn = blk, lt grn =yel and grn, brn =blu, yel =red

pencil light wire colours
red is stop
wht is earth
brn is tail
yel is indicator lh/rh



Review the wiring connections to the inboard two-color lamps...
  • Stop - brown (front) > red (both rear)

  • Tail - blue (front) > brown (both rear)

  • Left Turn - red (front) > yellow (left rear)

  • Right Turn - black (front) > yellow (right rear)

  • Earth (Ground) - white (front) > white (both rear)
          ...then refer to the above image.

The white (earth) wires from the LED lamps do not connect to the white (earth) wires from the front harness.  Unless there is a viable shunt between the "earth" bus and the LED 'earth' strip, the LED lamps are not properly grounded.  Otherwise, run a temporary jumper wire between the LED 'earth' strip and shiny, bare metal on the right frame rail to see if there is any improvement.
« Last Edit: September 22, 2017, 06:42:03 PM by bd »
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Online bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 6438
Re: side lights flash with indicators ( LED)
« Reply #10 on: September 22, 2017, 07:03:58 PM »
If the problem persists after the ground for the rear lamps has been verified, temporarily disconnect the front side markers (remove the bulbs) and recheck the rear lamps for symptoms.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline impco lpg

  • Newbie
  • Posts: 98
  • Newbie
Re: side lights flash with indicators ( LED)
« Reply #11 on: September 23, 2017, 06:36:24 AM »
there is a jumper earth wire fitted (black loop wire left side of box) and I have tried a separate earth just for the rear lamps (still fault)
when I removed the front marker bulbs (194) and (1157) both sides the rear lights work FINE AS THEY SHOULD NO RED FLASHING  :)
so do the front markers need resisters ? I have x4  50watt
« Last Edit: October 01, 2017, 09:33:51 AM by impco lpg »
1983 cucv m1009  blazer 6.2 4x4
1991 1500 suburban 5.7 4x4 lpg
2003 dodge ram 5.7 4x4 lpg
1985 chevy c10 stepside  2wd 5.7ltr 350 lpg

Online bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 6438
Re: side lights flash with indicators ( LED)
« Reply #12 on: September 24, 2017, 12:09:51 AM »
So, you're back to running incandescent bulbs up front instead of the LED lamps?  Recheck the grounds to the front park/turn lamps.  Reinstall the front 1157 and 194 bulbs.  Connect a voltmeter negative probe directly to the battery negative post.  Select the voltmeter DC 10 volts scale.  Connect the voltmeter positive probe to the left turn lamp ground wire.  Energize the left turn signal.  Measure and record the voltage drop.  Repeat the process with the voltmeter positive probe connected to the right front turn lamp ground wire.  Post the results.
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)

Offline impco lpg

  • Newbie
  • Posts: 98
  • Newbie
Re: side lights flash with indicators ( LED)
« Reply #13 on: September 24, 2017, 04:51:12 AM »
battery side: energize right turn .25 volt
                   energize left turn   .15 volt

NOT SURE IF IM DOING IT RIGHT :-[

« Last Edit: September 24, 2017, 04:56:12 AM by impco lpg »
1983 cucv m1009  blazer 6.2 4x4
1991 1500 suburban 5.7 4x4 lpg
2003 dodge ram 5.7 4x4 lpg
1985 chevy c10 stepside  2wd 5.7ltr 350 lpg

Online bd

  • Global Moderator
  • Senior Member
  • *****
  • Posts: 6438
Re: side lights flash with indicators ( LED)
« Reply #14 on: September 24, 2017, 10:29:34 AM »



Measure similarly on both sides.  This measurement checks the integrity of the ground return path to battery.
« Last Edit: September 24, 2017, 10:32:46 AM by bd »
Rich
It's difficult to know just how much you don't know until you know it.
In other words... if people learn by making mistakes, by now I should know just about everything!!!
87 R10 Silverado Fleetside 355 MPFI 700R4 3.42 Locker (aka Rusty, aka Mater)