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Bright headlights quit


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So I'm out on a road trip and last night when I turned my lights on the brights never came on, the bright is illuminated on the dash but no headlights, 

I  have just recently upgraded to the dual sport headlight from DAP, and before I left I also installed the relay wire harness kit from DAP, and they were all working fine for the last week or so. I still got the dim side but no brights. I checked fuses and relays and are still good, I am wondering if  it's in the mfs switch on column or light switch on dash,  Any ideas what to check, I'm out on a road trip so kind of limited to what I can do.

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Out on the road with no tools it's hard to do diagnostics let alone repairs but if you can get a test light or volt meter.....

With the head lights turned on use the 12v test light or volt meter and check for power at the blub. 

If power then bad blubs. 

If no power then check out put from terminal 87 of the hi beam relay. 

If power at terminal 87 then there is an open circuit between relay and blub.

If no power at terminal 87 then check for voltage at terminals 86 and 30 of the hi beam relay.

Terminal 30 is fused power from battery and 86 should have power when high beam indicator is illuminated.

 

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I got a chance to check it it today and found I did have a blown fuse on the high beam on the left side harness. Replaced it and have power at pin 87 but not 30 also have power at 86.

 

I can jump wire from battery to pin 30 and lights will come on, so my bulbs and conections should be good.

 

The right side harness is the exact same scenario, only no blown fuse.

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There should be power to terminal 30 of the high beam relay only when low beams are on.  When high beam is selected power is sent to terminal 86 and the coil is energized then the power will flow from terminal 30 to 87.    

When the head lights are turned on and there is power to terminal 87 and not 30 then I think the plug for the relay is is wired backwards.  

58df17b6d0220_62217_iso_relay_11.jpg.197d2fab87e4d1ee5e019c3e5597904d.jpg

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I will double check, but when I was checking on the low beam I think pin 30 was hot, that  was on the high beam relay

 

Strange if if it was wired backwards that it worked when first hooked up, but also the quality of the high beams were not as great as they should have but I thought they just needed adjusted up some. I will do some more digging on it this  weekend  at  home. 

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12 hours ago, 01cummins4ever said:

I will double check, but when I was checking on the low beam I think pin 30 was hot, that  was on the high beam relay

 

Strange if if it was wired backwards that it worked when first hooked up, but also the quality of the high beams were not as great as they should have but I thought they just needed adjusted up some. I will do some more digging on it this  weekend  at  home. 

Once you get high beams working check out post from January 18. There is a write up and pictures to repin the plugs. Makes the lights better.

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Well I determined the mfs switch was not at fault, I just plugged a bulb directly into the factory side of harness and it functions correctly on both sides.

 

I removed the high side relays and tested them on bench and they both failed, so something blew them out. @IBMobile is right that something is not wired up right. I don't know but could the plugs in the headlights be reversed?

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20 minutes ago, Mopar1973Man said:

I'm not fond of that relay setup that most are selling. I'm going to get back to the relay mod I'm going to build for my truck tomorrow. I'm going to do it with 2 relays and one fuse possibly. Still doing my beta test work on my design. 

I agree with you, I wish you luck on building your own,  I was in a hurry so I went this route,  

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Anybody got a wire diagram for the sportheadlight conversion harness DAP sells, I found this diagram but not sure if its wired the same as the one from DAP. I would think it would be the same layout, not sure though. I do know that the pins on my headlight plugs need changed because they are both for 9004 bulbs and the lights come with 9004 and 9007 bulbs, that's an easy fix, but on mine the relay plugs they both have pin 87 wired on the power in  side and pin 31 wired on the power out going to the bulbs??  doesn't make since,   For a 150 dollar harness, I really dont think I need to be changing wires around but I would like to get this figured out before I take the next step.

here is the diagram I am using for reference

 

 

Dodge Ram Sport Headlight Conversion.pdf

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  • Owner

I should hand draw my setup. I've got it working and doing very well so far. Still just 2 relays and 1 fuse setup. Currently only controlling the secondary bulbs of the sport headlights. I'm going to convert to controlling all 4 bulbs really soon. Still only be 2 relays and 1 fuse even then. 

 

Basically in words one relay controls the low beam. Then the other relay controls the high beam. So you'll need 1 male headlight plug, 4 female headlight plugs, 2 40 amp relays, and 1 fuse holder with a 30 Amp fuse. 

 

headlights.jpg

 

Image result for automotive relay pins

 

So wiring wise pretty simple. 85 and 86 of the relay will hook to the driver side head light plug. So for explaining purpose both relays 86 will be hooked to the "B" position of the headlight plug. The lo beam relay 85 pin will be to the "A" position of the headlight plug. So then the hi beam relay 85 pin will be on the "C" position of the headlight plug. Now your power you get from the PDC on the alternator fuse terminals (RED). This lead will hook to pin 30 on both relays. Now 87 (I'm using 5 pin relays). Will go to each filament of each bulb. Remember which relay you working with so "lo beam" relay would hit all lo beam filaments. Then your hi beam relay 87 would hit all the high beam filaments. So I jumped under the radiator to follow the OEM loom. Repeat the same on the other side. Then the ground I just used the fender ground for the headlights. 

 

Image result for 9004 and 9007 pins

 

I know its crude but it's a beta testing in progress... Fuse is out of sight but it hooked up in the PDC on the battery lead side of the alternator fuse. 

DSCF4010.JPG

 

 

Both bulbs are lit...

DSCF4012.JPG

Edited by Mopar1973Man
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  • Owner

@IBMobile That won't work. 85 pins can't have reference to ground. It has to return to the head light (B) position. This was a mistake I made in my first attempt and will cause light to be on always. Because the circuit is +12V hot already so a source to ground will trigger the relays. Stock system the headlight switch and dimmer control the ground. 

 

The rest is correct though... :)

Edited by Mopar1973Man
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On ‎4‎/‎2‎/‎2017 at 6:49 PM, Mopar1973Man said:

 I'm going to do it with 2 relays and one fuse possibly. 

 

I understand and I like having a simple circuit, but are you not concerned about having only one fuse for all of the headlights?  If that fuse blows for any reason, it could be exciting getting your truck stopped. 

 

Also, are you using heavier gauge wire from the 87 terminal of each relay to each headlight, or are you tapping into the existing very small wiring to each headlight?

 

- John

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1 hour ago, Mopar1973Man said:

Stock system the headlight switch and dimmer control the ground. 

redone58e9b75303c88_Sport20headlight20harness_zpskz036rjr2.png.14dc5de2eff9acdcf902f3d00b5088dd.png

 

1 hour ago, 01cummins4ever said:

Then the yellow is pin 85  and red is 86

So the red wire to terminal 86 is powered from fuse B or C in the PDC for the right or left head light respectively.  Does the power to terminal 86 stop when the fuse is pulled?  The yellow wire to terminal 85 should go to pin 20 in the high beam selector switch via the red/orange wire and is a ground. 

The black and white wires should be switched.  Fused battery power to terminal 30 (black wire) and switched power out of relay through terminal 87 (white wire) to high beam terminals of the blubs.

Edited by IBMobile
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  • Owner

No need to run back to the headlight switch in the cab just use the head light plug right there for A, B and C contacts. 

(refer back to my wiring diagram - https://mopar1973man.com/topic/12500-bright-headlights-quit/?do=findComment&comment=154457)

 

 

B is fused +12V power

 

A is lo beam (ground)

C is hi beam (ground)

 

Lo beam relay "A" to 85 and "B" to 86

Hi beam relay "C" to 85 and "B" to 86

 

This will reduce the amount of wire distance and need to run into the cab. 

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