The 1947 - Present Chevrolet & GMC Truck Message Board Network







Register or Log In To remove these advertisements.

Go Back   The 1947 - Present Chevrolet & GMC Truck Message Board Network > General Truck Forums > Electrical

Web 67-72chevytrucks.com


Reply
 
Thread Tools Display Modes
Old 06-04-2019, 01:11 AM   #1
siggyfreud
Registered User
 
siggyfreud's Avatar
 
Join Date: Jun 2012
Location: Portland
Posts: 936
Wiring up new headlights, can't figure out how to make this work

Hey all,

Went to wire up some new headlights today. They're HID lights, with an outer halo. Got the headlights themselves working, but I'm getting stuck on the switchback wiring. Essentially, the outer white halo acts as a DRL, but when I use a turn signal, it switches and flashes amber, then goes back white when it's not a turn signal. Wiring for the switchback is as follows:

Black Wire - Ground
White wire - Dim halo 50% power - Park lights on mode
Red Wire - Full halo 100% power - Daytime Running Light (ignition on power)
Yellow Wire - Turn signal power



So here is the problem:

1. At first, I wired it to the turn signal wires that fed the original front turn signals. However, those wires have a constant 5.5v when park lights are on, which was keeping the amber halo active. Technically, one wire has 12v with park lights on, the turn signal feed wire then gets 5.5v.

2. Second, I tried going right from the column turn signal wires, however, I then realized the front ambers were coming on when I depressed the brakes, as the brake circuit runs through the column wires, then out to the rear.

I'm not sure I have a solution here. I've looked at all the turn signal power sources and they all seem to carry a steady 5.5v when the park lights are engaged and jump to 12v with the "flash" of the turn signal. Anyone have any suggestions here?
siggyfreud is offline   Reply With Quote
Old 06-04-2019, 12:09 PM   #2
starterman99
Registered User
 
starterman99's Avatar
 
Join Date: Jun 2008
Location: santa maria,ca.
Posts: 280
Re: Wiring up new headlights, can't figure out how to make this work

First thought would be a ground issue causing a feedback in the rear tail light assembly.
__________________
1957 3100
1950 5 window
starterman99 is online now   Reply With Quote
Old 06-04-2019, 12:35 PM   #3
siggyfreud
Registered User
 
siggyfreud's Avatar
 
Join Date: Jun 2012
Location: Portland
Posts: 936
Re: Wiring up new headlights, can't figure out how to make this work

As in that's the reason for the 5.5V in the turn signal circuit when park lights are on? If so, what do you suggest? There are no separate grounding wires back there since one is park light power, and the other turn signal power.
siggyfreud is offline   Reply With Quote
Old 06-04-2019, 01:34 PM   #4
starterman99
Registered User
 
starterman99's Avatar
 
Join Date: Jun 2008
Location: santa maria,ca.
Posts: 280
Re: Wiring up new headlights, can't figure out how to make this work

Resistance on the ground side of tail light housing to the bed or bed to frame would feed back thru turn bulb.
I would pull the bulbs out of the rear lights one at a time and see if the 5.5 goes away. that would tell you what side to look at. if turn and park lights are in common housing in front I would also pull those bulbs to find where the feedback is coming from. Once you narrow it to source then you can work on resolving that.
__________________
1957 3100
1950 5 window
starterman99 is online now   Reply With Quote
Old 06-05-2019, 12:49 AM   #5
siggyfreud
Registered User
 
siggyfreud's Avatar
 
Join Date: Jun 2012
Location: Portland
Posts: 936
Re: Wiring up new headlights, can't figure out how to make this work

So the first bulb I pulled, driver side front park/turn light, killed the 5.5v to that circuit. I'm not sure how to resolve it though. How do I better-ground that light with the 2 wires coming from it both being power?
siggyfreud is offline   Reply With Quote
Old 06-05-2019, 06:48 AM   #6
rpmerf
Registered User
 
rpmerf's Avatar
 
Join Date: Feb 2011
Location: Parkville, MD
Posts: 657
Re: Wiring up new headlights, can't figure out how to make this work

Yes, better ground. It grounds through the housing. Look how the hosing connects to the body, and make sure the contacts are clean.
__________________
1970 C20 Custom Camper - 350, TH350
1997 GMC Suburban
1994 Acura Integra GSR
1987 Dodge Daytona Shelby Z
rpmerf is offline   Reply With Quote
Old 06-05-2019, 11:56 AM   #7
starterman99
Registered User
 
starterman99's Avatar
 
Join Date: Jun 2008
Location: santa maria,ca.
Posts: 280
Re: Wiring up new headlights, can't figure out how to make this work

I have also seen bad connection between the bulb holder and the housing. Also check to make sure you have the right bulb.A single element bulb crammed into double element socket will cause feed back.
__________________
1957 3100
1950 5 window
starterman99 is online now   Reply With Quote
Reply

Bookmarks

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump


All times are GMT -4. The time now is 08:59 PM.


Powered by vBulletin® Version 3.8.11
Copyright ©2000 - 2019, vBulletin Solutions Inc.
Copyright 1997-2013 67-72chevytrucks.com