Did i burn up my dimmer switch?

[QuadRunnerJake]

So basically i got myself a set of NHK projectors and retrofitted them into the autosaver 88 single piece headlights [non sport]. tested the plugs before i started building the harness. so after testing the pins i got : Low beam; pin1 12v pin 2 grnd, pin 3 inactive Hi beam; pin 1 ground, pin 2 inactive, pin 3 12v also noted that pin 1 is +12v even when headlights are off. So i built the harness and in the meantime something happened and now pin 3 is always hot. im over 12 hours into building the harness and this ****ery happens. im assuming a bad dimmer switch? the hi beam indicator still works which throws me off. pin 1 still acts normal switching from hot to ground when switching from lo to hi beam but pin 3 stays hot even with the truck off now. pin 1 is normally hot when truck is off but that should be the only pin hot when off.

My harness is wired like this; pin 1 goes to relay coil, pin 2 and 3 go to the other end of the relay coil. in theory when low beam is active pin 1 will give hot and pin 2 will give ground to activate coil, in hi beam pin 1 is ground and pin 3 provides 12v to coil. this allows the relay to activate during high and lo beam to keep the projector powered. the projector hi beam solenoid is wired to pin 1 and 3 directly and only activates during high beam. since pin 2 and 3 completely disconnect from circuit during lo and hi beam operation [no continuity] i decided not to use schottky diodes for reverse current protection. i do have them if i need them but i dont think so since there isnt continuity between the pins 2 and 3 when low or hi beam is active. the harness isnt plugged into anything now and i currently have no headlights so please help with any advice.
thanks in advance,

Jacob

2001 non sport

Please note the factory plug is malfunctioning and pin 3 is staying hot at all times now with my harness removed.

[Tractorman]

I am a bit lost with your explanation.  I don't see any of the terminal pin numbers that you refer to, so I don't know which connectors you a referring to.  Also, the type of relay you are using (not part of the diagram below) isn't identified.

 

The headlight wiring diagram below is for a 2002 Dodge Ram (probably the same for a 2001).  The "double asterisk" by each headlight represents the connection to a "non Quad" headlight system.  You will note that terminal "A" at each headlight is always hot via two separate 15 amp fuses in the PDC.

 

Low beam is selected by grounding terminal "B" of the headlight via the multi-function switch and then the headlight switch.

 

High beam is selected by grounding terminal "C" of the headlight via the multi-function switch.

 

It will help if you show the type of relay that you are using so that the wiring can be understood easier.

 

- John

 

Edited June 29 by Tractorman

[QuadRunnerJake]

 lamp system.
Before i tested my harness:
pin 1 is R/O and is hot when vehicle is off and when low beams are on, Ground when hi beam is on
Pin 2 V/W is ground only when low beam active
pin 3(V/R) is hot only when hi beams are on
After i tested harness
Pin 1 hot when vehicle is off and when low beams are on, Ground when hi beam is on
Pin 2 ground only when low beam active
Pin 3 always hot

 

 

please note everything is unplugged when testing. i am testing the 9004 sockets with a power probe

i have nothing aftermarket hooked up to my system whn testing

 

how should my 9004 plug behave in off lo and hi conditions?

[Tractorman]

40 minutes ago, QuadRunnerJake said:

Before i tested my harness:
pin 1 is R/O and is hot when vehicle is off and when low beams are on, Ground when hi beam is on
Pin 2 V/W is ground only when low beam active
pin 3(V/R) is hot only when hi beams are on

 

I am still not sure where you are getting Pin #1, #2, and #3 information from.  Regardless, the wire colors you mention are for the right side headlight.  I am going to use the FSM wiring diagram for reference.

 

RIght side headlight:

 

** A - VT/RD - 15 amp hot fuse from PDC

** B - VT/WT - low beam wire to dimmer switch, then headlight switch, then to ground

    C - RD/OR - high beam wire to dimmer switch, then to ground

 

Left side headlight is the same except that **A is VT and has a separate 15 amp hot fuse from the PDC.

 

54 minutes ago, QuadRunnerJake said:

please note everything is unplugged when testing

 

What does "everything" mean? - both headlight connectors? dimmer switch, headlight switch?  Have the bulbs be removed?

 

56 minutes ago, QuadRunnerJake said:

i am testing the 9004 sockets with a power probe

 

I would not use a power probe for testing.  I would use a test light with and incandescent bulb.  I would leave everything connected except for the left and right headlight connectors. Both connectors should have the 9004 bulbs removed.  I would turn the headlights to the "ON" position and have the dimmer switch selected to low beams.

 

**A - test lamp clamped to battery ground and test lamp probe connected to **A.  Test lamp should light (power from 15 amp fuse).

 

**B - test lamp clamped to battery positive post and test lamp probe connected to **B.  Test lamp should light (ground through headlamp switch via dimmer switch).

 

C - Activate high beam switch.  Test lamp clamped to battery positive post and test lamp probe connected to C.  Test lamp should light (ground through high beam selector switch.

 

Just for general information (and maybe you already know this), but the headlight switching is all in the ground circuit.  When the bulbs are removed, the only voltage that can be present is at terminal **A at both headlight connectors.  The remaining terminals will be either open or grounded depending on position of switches.

 

Hopefully, I have not made any errors - feel free to correct them if I did.

 

- John

 

 

 

 

[QuadRunnerJake]

35 minutes ago, Tractorman said:

am still not sure where you are getting Pin #1, #2, and #3 information from.  Regardless, the wire colors you mention are for the right side headlight.  I am going to use the FSM wiring diagram for reference.

1 2 and 3 is the pins order from right to left. i added the colors to my last reply.

35 minutes ago, Tractorman said:

What does "everything" mean? - both headlight connectors? dimmer switch, headlight switch?  Have the bulbs be removed?

 

headlights removed, my relay adapter harness removed, bulb removed

 

35 minutes ago, Tractorman said:

2 hours ago, QuadRunnerJake said:

i am testing the 9004 sockets with a power probe

 

i am only using the power probe as a multimeter. 

35 minutes ago, Tractorman said:

**A - test lamp clamped to battery ground and test lamp probe connected to **A.  Test lamp should light (power from 15 amp fuse).

 

**B - test lamp clamped to battery positive post and test lamp probe connected to **B.  Test lamp should light (ground through headlamp switch via dimmer switch).

 

C - Activate high beam switch.  Test lamp clamped to battery positive post and test lamp probe connected to C.  Test lamp should light (ground through high beam selector switch.

 

Just for general information (and maybe you already know this), but the headlight switching is all in the ground circuit.  When the bulbs are removed, the only voltage that can be present is at terminal **A at both headlight connectors.  The remaining terminals will be either open or grounded depending on position of switches.

 

i am aware of the ground switching. i do not understand why R/O wire is 11.4v until hi beams are activated and it turns to ground (showed like .5v ground), vt/w acts normal and only grounds when low beam is activated, Vt/R or V shows about 11.9v all the time. so the only wire in question is the R/O wire. Why the hell is it showing 11.4v unless hi beams are active?

i might just have to add a shottky diode to get rid of that positive signal on the R/o wire and only allow ground through.

Please dont judge but i dont own a test light lol, i have a power probe and multimeter

Edited June 30 by QuadRunnerJake
clarification

[Tractorman]

No judging at all - you have to use the tools that you have on hand.  Appreciate you answering all the questions.

 

58 minutes ago, QuadRunnerJake said:

my relay adapter harness removed, bulb removed

 

Just double checking here - "bulb" is singular - both bulbs need to removed for the test, otherwise back-feeding will occur through the bulb filaments.  Also, with your relay adapter harness removed, is the wiring harness now completely stock?

 

58 minutes ago, QuadRunnerJake said:

i do not understand why R/O wire is 11.4v until hi beams are activated and it turns to ground (showed like .5v ground),

 

This sounds like stray voltage to me.  This can happen when a wire both ends of a wire a renot connected in a particular switching operation.  It is one of the reasons that I use a test light with an incandescent lamp when testing these circuits.  The imposed electrical load from the incandescent lamp eliminates stray voltage from the picture.  Multi-meters will easily read any voltage present - even if it is stray and is not backed.  The fact that the voltage disappeared when high beam was selected indicates the circuit is working - maybe not the best it could be, but it is working.

 

The .5 voltage drop to ground when the high beam is activated sounds like a poor ground connection, but should not be causing you any problems. 

 

- John

 

Edited June 30 by Tractorman

[QuadRunnerJake]

17 hours ago, Tractorman said:

ust double checking here - "bulb" is singular - both bulbs need to removed for the test, otherwise back-feeding will occur through the bulb filaments.  Also, with your relay adapter harness removed, is the wiring harness now completely stock?

yes no bulbs and my adapter harness's removed. just 2 empty 9004 plugs. 

 

17 hours ago, Tractorman said:

This sounds like stray voltage to me.  This can happen when a wire both ends of a wire a renot connected in a particular switching operation.  It is one of the reasons that I use a test light with an incandescent lamp when testing these circuits.  The imposed electrical load from the incandescent lamp eliminates stray voltage from the picture.  Multi-meters will easily read any voltage present - even if it is stray and is not backed.  The fact that the voltage disappeared when high beam was selected indicates the circuit is working - maybe not the best it could be, but it is working.

 

very odd phenomenon. im going to add a shottky diode to it and only allow ground to pass through r/o. its weird that when it switches to ground .5v, that .5v is the difference between the r/o when its hot (11.4) and V/R wire 11.9..... that 11.4 stays even after i try to ground it out to see if its just residual current being held by something like a cap.

Also do you think this stray voltage is coming from the beam selector or the headlight switch

My main goal is to get my NHK BI LED projector to  work lol along with the solenoid

Someone on another forum suggested the high beam indicator circuit may be at fault

Also since i have a power probe i can check for noise in the circuit as well

[Tractorman]

1 hour ago, QuadRunnerJake said:

Someone on another forum suggested the high beam indicator circuit may be at fault

 

I think that "someone" is correct, although I don't consider it to be a fault.  The stray voltage is coming from the high beam bulb.  That bulb is fed by Fuse #14 (10 amp from battery) in the PDC.  That bulb is grounded when high beam is selected.  When low beam is selected, the bulb is not grounded - hence, voltage is present at the RD/OR wire via Fuse #14 and the high beam indicator bulb.

 

So, I think your OEM headlight circuit is working as it should.

 

- John

 

Edited June 30 by Tractorman

[QuadRunnerJake]

1 hour ago, Tractorman said:

I think that "someone" is correct, although I don't consider it to be a fault.  The stray voltage is coming from the high beam bulb.  That bulb is fed by Fuse #14 (10 amp from battery) in the PDC.  That bulb is grounded when high beam is selected.  When low beam is selected, the bulb is not grounded - hence, voltage is present at the RD/OR wire via Fuse #14 and the high beam indicator bulb.

OH BOY, this is the answer. I will add a Shottky diode to my harness on R/O wire to block the positive signal and only allow ground.  Thank you so much for all of your help. I will make a post with the finished product once i get my adapter harness rebuilt. Basically its going to go something like this: VT/RD > relay coil pin 85, V/W>relay coil pin 86, R/O>shottky Anode>pin 86 relay coil, pin 30 relay common > fuse> battery positive, pin 87 relay power> projector hot

[QuadRunnerJake]

 i assume that .4v is what the high beam indicator bulb uses up... Maybe 12v is passing through the indicator bulb at all times from the fuse you mentioned and since it isnt grounded when high beams are off the current runs through the indicator bulb filament and is then forwarded to R/O from R/GY. Thats what i came up with from looking at page 908 and 961 of the online service manual. i dont get how that doesnt casue a short in the oe bulb with R/O and VT/RD both hot

Edited July 1 by QuadRunnerJake

[Tractorman]

1 hour ago, QuadRunnerJake said:

 i assume that .4v is what the high beam indicator bulb uses up...

 

I think you would be correct.  Sounds like you will have a new relayed headlight system that you will be happy with, soon.

 

The diagram below shows how I wired relays into the existing 2 headlight system when my truck was new.  Later, I modified the diagram for a Sport headlight system.  The numbers by the wiring represent wire gauge. 

 

Years ago, I lost my high beam indicator lamp - I always thought that it burned out, but now I am wondering if I sabotaged that circuit!

 

- John

 

Edited July 1 by Tractorman

[QuadRunnerJake]

Yeah i decided to only use a single relay for high/low beam. So 2 relays for both headlights and 2 shottky diodes on each light.. 2 relays seems overkill for my single BiLed system... I only had forward biased shottkys so i had to get creative with the junction point locations where the solenoid tapped in and diode orientations since VT and VT/R will backfeed through the relay coil. How did you draw that diagram??? i can post up my schematic tomorrow.

On 6/30/2024 at 9:01 PM, QuadRunnerJake said:

dont get how that doesnt casue a short in the oe bulb with R/O and VT/RD both hot

i think the filament works as a resistor to limit the current draw. Still this set up causes a constant drain on the battery when truck is off because it is in fact shorting at the headlight bulb.

[Tractorman]

1 hour ago, QuadRunnerJake said:

How did you draw that diagram???

 

I use software called DesignCad 2018.  It started out as Prodesign in 1985, when I first started using it. 

.

1 hour ago, QuadRunnerJake said:

On 6/30/2024 at 7:01 PM, QuadRunnerJake said:

dont get how that doesnt casue a short in the oe bulb with R/O and VT/RD both hot

i think the filament works as a resistor to limit the current draw. Still this set up causes a constant drain on the battery when truck is off because it is in fact shorting at the headlight bulb.

 

There is no short to ground when the headlight switch is turned off and headlight beam selector switch set on low beam.  It is just battery voltage potential with an incomplete path, so no current flows.

 

- John

[QuadRunnerJake]

. the voltage potential is different between VT and R/O by .4v which made me think that the lower voltage potential would draw from the higher. I guess i would have to test Amps to see if that is the case but yeah im probably still wrong. Its been a long time since ive taken a circuits course lol