LED conversion

Disclaimer: Links on this page pointing to Amazon, eBay and other sites may include affiliate code. If you click them and make a purchase, we may earn a small commission.

84Dually

Junior Member
Joined
Aug 3, 2024
Posts
2
Reaction score
2
Location
Kentucky
First Name
Reese
Truck Year
1984
Truck Model
C30
Engine Size
454
Hello everybody, first post here. Have gone through a few threads but havent found anything helpful to my situation.
Have had LED lights in all of my running lights + cab lights and never had an issue. Recently though i install a set of LED headlights and am now running into issues. My front fender sidemarkers no longer light up at all, my dash turnsignal lights remain lit, and both sides of lights flash when the turnsignal is activated. I have installed a set of LED flashers and got the same results. Im not the savviest electrically but any input helps!
 

dsteelejr

Full Access Member
Joined
May 25, 2020
Posts
239
Reaction score
231
Location
Hudson, WY
First Name
David
Truck Year
1973, 1980
Truck Model
Cheyenne super C20 camper special, Sierra K25
Engine Size
350, 454
Headlights and turn signals are on separate circuits, I don’t see how adding headlights would affect turn signals. You only had problems with the turn signals after installing LED head lights?

I still use sealed beam halogen headlights, but I had issues with the LED side marker/turn light when I switched to LED bulbs. Only way I could fix it was to use LED flashers, which I read you already have, in conjunction with LED side markers from LMC. Replacing the bulbs seems to work with everything except the side marker/turn lights. I had to get the complete, sealed LED unit.

 

84Dually

Junior Member
Joined
Aug 3, 2024
Posts
2
Reaction score
2
Location
Kentucky
First Name
Reese
Truck Year
1984
Truck Model
C30
Engine Size
454
Headlights and turn signals are on separate circuits, I don’t see how adding headlights would affect turn signals. You only had problems with the turn signals after installing LED head lights?

I still use sealed beam halogen headlights, but I had issues with the LED side marker/turn light when I switched to LED bulbs. Only way I could fix it was to use LED flashers, which I read you already have, in conjunction with LED side markers from LMC. Replacing the bulbs seems to work with everything except the side marker/turn lights. I had to get the complete, sealed LED unit.

Forgot i had done LED bulbs in my behind grille park lights. Removed bulbs and everything seems to be back to normal. Id like to be able to run them in the front aswell though.
 

TotalyHucked

Full Access Member
Joined
Feb 24, 2020
Posts
3,669
Reaction score
11,853
Location
Auburn, Georgia
First Name
Zach
Truck Year
1985
Truck Model
Sierra 1500
Engine Size
5.3
What do you have for tail lights?

For my '85, I have LED's everywhere including the tail lights. I had to wire in 50ohm resistors for each tail light and each marker light in the grille. So I have four 50ohm resisters in my truck. The LED flasher did nothing.
 

Jgonick

Full Access Member
Joined
Jan 12, 2017
Posts
296
Reaction score
376
Location
West Texas
First Name
Joel
Truck Year
1985
Truck Model
K10
Engine Size
350
Found these and thought they were excellent showing how the front park/dir lamp works with the side marker lamp.

Side marker lamps have current coming from different directions depending if lights are on or not.
LEDS (light emitting diodes) only allow current in one direction- unless modified somehow.

Front park/dir lamps have dual filament bulbs. The side marker lamp uses one of the filaments to go to ground and which filament it uses depends if the lights are on or not.
 

Attachments

  • 1_alternating_marker.jpg
    1_alternating_marker.jpg
    65.6 KB · Views: 40
  • 2_alternating_marker.jpg
    2_alternating_marker.jpg
    69.8 KB · Views: 42
  • 3_alternating_marker.jpg
    3_alternating_marker.jpg
    68.4 KB · Views: 45
Last edited:

geauxnow

Junior Member
Joined
Mar 5, 2024
Posts
8
Reaction score
4
Location
DFW
First Name
Matt
Truck Year
1989
Truck Model
V1500 Chev Suburban
Engine Size
350
What do you have for tail lights?

For my '85, I have LED's everywhere including the tail lights. I had to wire in 50ohm resistors for each tail light and each marker light in the grille. So I have four 50ohm resisters in my truck. The LED flasher did nothing.
Did you wire it in series or did you place it across the line and load?
 

Tonimus

Full Access Member
Joined
Sep 17, 2024
Posts
63
Reaction score
108
Location
Phoenix
First Name
Tony
Truck Year
1978
Truck Model
C10 Suburban
Engine Size
454

Adjustable speed flashers always work in my experience. I have one in my motorcycle, a friends VW Bug, and a few others. The only "downside" is that it will not hyperflash if you have a bulb out. It will happily flash away, even driving just a test light.
 

Forum statistics

Threads
44,156
Posts
950,542
Members
36,268
Latest member
JUKA
Top