73-87chevytrucks.com

73-87 Chevy _ GMC Trucks => Electrical => Topic started by: Jay2D2 on February 06, 2009, 07:26:29 AM

Title: Lighting Issue
Post by: Jay2D2 on February 06, 2009, 07:26:29 AM

Ok here's a good one for you guys.

85 C10 with Quad Lights.
When the low beams are on the 2 low lights work
When you hit the high beams the 2 high lights work
However when the highs are on, only one low beam lights.
All lights are good at one time or another just not all at once.

Suggestions?

Title: Re: Lighting Issue
Post by: 69byrd on February 06, 2009, 07:41:42 AM

Are you sure they are good? Reason I ask is when I put the front back on my truck, I put the lights that came off of it back on it. They had been sitting on a shelf for about 7 months, they worked good when they came off the truck but when I put them back on I had a problem similar to yours. I replaced the lights and they have worked fine ever since.

Title: Re: Lighting Issue
Post by: Jay2D2 on February 06, 2009, 08:06:09 AM

Good for sure, he bought 2 new ones plus even switched there sides... always the same side that doesnt work.

I neglected to mention I know of 2 other local trucks that seem to have this problem

Title: Re: Lighting Issue
Post by: frogman68 on February 06, 2009, 10:10:44 AM

Have you verified voltage at the plug sounds like a broke wire..

Title: Re: Lighting Issue
Post by: Jay2D2 on February 06, 2009, 10:40:13 AM

hmm i dont think it would be a broken wire, because the low beam will light on low beam, just not on high beam

Title: Re: Lighting Issue
Post by: frogman68 on February 06, 2009, 10:46:04 AM

Dont have a wiring diagram with me but I think the low beam is a dual filament bulb so that when you hit the high beams the higher wattage filament lights, think its a separate wire for that.

Title: Re: Lighting Issue
Post by: Jay2D2 on February 06, 2009, 11:09:34 AM

going on memory the light is just a 2 prong
though i could be wrong on that

Title: Re: Lighting Issue
Post by: frogman68 on February 06, 2009, 11:24:12 AM

Quote from: Jay2D2 on February 06, 2009, 11:09:34 AM

going on memory the light is just a 2 prong
though i could be wrong on that

 the 2 prong (H4651 / 4651) is the high beam
I am thinking that the (h4652 / 4652) is a 3 prong that is the low beam.

Title: Re: Lighting Issue
Post by: Jay2D2 on February 06, 2009, 11:27:13 AM

it is possible

have to go look tonight

Title: Re: Lighting Issue
Post by: frogman68 on February 06, 2009, 11:31:33 AM

Not sure this is correct but it does say it replaces the h4652 / 4652

http://www.ryderfleetproducts.com/cgi-bin/ryderfp/products/srm/oid/45565/pn/Sealed-Beam-Lamp-Rec-58-H-D-Truck-Blade-Term/erm/product_detail.jsp

Title: Re: Lighting Issue
Post by: farmallgray on February 06, 2009, 02:41:04 PM

The low beam bulbs have two filaments. I would say the low beam filament in one of your low beam bulbs is burned out.
You either need a 4652 (non halogen) or an H4656 (halogen) low beam replacement.

Under edit; I see you said you tried new bulbs. In that case I vote for a bad connection and keep in mind that they are a 3 prong bulb so it is possible that they light on high but not low.

Title: Re: Lighting Issue
Post by: VileZambonie on February 06, 2009, 04:06:05 PM

The low beam is a dual filament bulb. Check your connections and or the bulb.