Installed GMC Grille today have a question - The 1947 - Present Chevrolet & GMC Truck Message Board Network

Irishbleueyes · 07-28-2013, 04:01 PM

Turned on the low lights and the hi's have a glow then switch over to the hi's and the low's have a glow, is that normal??

Irishbleueyes · 07-28-2013, 04:26 PM

Quote:

Originally Posted by Irishbleueyes

Turned on the low lights and the hi's have a glow then switch over to the hi's and the low's have a glow, is that normal??

Heres the pics

McCoyAZ · 07-28-2013, 04:35 PM

Mine do not do that.

Maybe a grounding issue?

63burban · 07-28-2013, 05:15 PM

Yup, ground issue

markeb01 · 07-28-2013, 09:02 PM

Are you sure you have them wired up correctly? It sounds like the wiring is connected backwards. It may be wired incorrectly at the grille harness, from where it connects to the bulkhead connector next to the radiator, or the wires may be mixed up and running to the wrong bulb connectors.

The way these four lamps systems work - High beam bulbs only have one filament and a two prong connector on the back. The low beam bulbs have two filaments and a 3 prong connector in the back. The two filaments in a low beam lamp are 1. High Power - this is the normal low beam lamp output. 2. Marking light/dim power. When high beams are selected at the dimmer switch, the normal low beam filaments in the low beam lamps go out, and the dim filament lights up to serve as a marker to show you have 4 headlamps.

You may find the wiring diagram in the following thread helpful in debugging the system. Just ignore the relays and follow the wiring from the battery and dimmer switch to the lamps. You'll notice the high beam lamps are wired to the low power filament in the low beam lamps. Something in this circuit is the source of your problem:

http://67-72chevytrucks.com/vboard/s...d.php?t=387693

ky-donzi · 07-28-2013, 09:08 PM

Ground is unhooked, or bad connection...so to complete the circuit it's drawing a ground through the other lamp.... It can burn up your wiring do to the extra amps drawn though the circuit
Posted via Mobile Device

ky-donzi · 07-28-2013, 09:16 PM

Ground is unhooked, or bad connection...so to complete the circuit it's drawing a ground through the other lamp.... It can burn up your wiring do to the extra amps drawn though the circuit
Posted via Mobile Device

07-28-2013, 04:01 PM	#1
Irishbleueyes Registered User Join Date: Apr 2012 Location: Solvang, Ca 93463 Posts: 323	Installed GMC Grille today have a question Turned on the low lights and the hi's have a glow then switch over to the hi's and the low's have a glow, is that normal??

07-28-2013, 04:35 PM	#3
McCoyAZ Registered User Join Date: Aug 2011 Location: Kingman, AZ Posts: 1,574	Re: Installed GMC Grille today have a question Mine do not do that. Maybe a grounding issue? __________________ http://s994.photobucket.com/albums/af62/ScottAz2/

07-28-2013, 05:15 PM	#4
63burban Chevy addict Join Date: May 2012 Location: Iron Ridge, WI Posts: 1,085	Re: Installed GMC Grille today have a question Yup, ground issue

07-28-2013, 09:02 PM	#5
markeb01 Senior Enthusiast Join Date: Feb 2007 Location: Spokane Valley, WA Posts: 8,356	Re: Installed GMC Grille today have a question Are you sure you have them wired up correctly? It sounds like the wiring is connected backwards. It may be wired incorrectly at the grille harness, from where it connects to the bulkhead connector next to the radiator, or the wires may be mixed up and running to the wrong bulb connectors. The way these four lamps systems work - High beam bulbs only have one filament and a two prong connector on the back. The low beam bulbs have two filaments and a 3 prong connector in the back. The two filaments in a low beam lamp are 1. High Power - this is the normal low beam lamp output. 2. Marking light/dim power. When high beams are selected at the dimmer switch, the normal low beam filaments in the low beam lamps go out, and the dim filament lights up to serve as a marker to show you have 4 headlamps. You may find the wiring diagram in the following thread helpful in debugging the system. Just ignore the relays and follow the wiring from the battery and dimmer switch to the lamps. You'll notice the high beam lamps are wired to the low power filament in the low beam lamps. Something in this circuit is the source of your problem: http://67-72chevytrucks.com/vboard/s...d.php?t=387693 __________________ My Build Thread: http://67-72chevytrucks.com/vboard/s...d.php?t=444502

07-28-2013, 09:08 PM	#6
ky-donzi Registered User Join Date: Jun 2012 Location: madisonville ky Posts: 311	Re: Installed GMC Grille today have a question Ground is unhooked, or bad connection...so to complete the circuit it's drawing a ground through the other lamp.... It can burn up your wiring do to the extra amps drawn though the circuit Posted via Mobile Device __________________ 61 GMC 4x4 1-ton flatbed 4bt cummins, ranger od, sm465, np 205, d60F, d70R 4.11 10,000 ramsey PTO winch.... SOLD 73 k5 gm crate 350-265 / sm465 / np205 3.73 posi

07-28-2013, 09:16 PM	#7
ky-donzi Registered User Join Date: Jun 2012 Location: madisonville ky Posts: 311	Re: Installed GMC Grille today have a question Ground is unhooked, or bad connection...so to complete the circuit it's drawing a ground through the other lamp.... It can burn up your wiring do to the extra amps drawn though the circuit Posted via Mobile Device __________________ 61 GMC 4x4 1-ton flatbed 4bt cummins, ranger od, sm465, np 205, d60F, d70R 4.11 10,000 ramsey PTO winch.... SOLD 73 k5 gm crate 350-265 / sm465 / np205 3.73 posi

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