No turn or hazard when headlight switch is on
 

Me again...
I am an led fenatic, i have replaced every bulb in my 1994 gmc jimmy s15 to led including the headlights. I also replaced both flashers to electronic. My issue now is that all the turn signals and hazards work great, but when i turn on the parking or headlights the turn and hazard act like incandescent, they do nothing...

I disconnected the headlights and no improvement... Does anyone have a resolution? I am thinking the switch cannot handle the current but i disconnected the headlight which draw allot of currant, not sure what is the issue...

No turn or hazard
 

Well i will try this one more time with better explanation...hello,

i changed all my exterior and interior bulbs to led. I installed led electronic flashers and hade led headlights.

All worked fine, hazards work, turns work and all lights are lit. When i turn on the parking or headlights with the turns or flashers on, they freeze up and do not operate. I unplugged the headlights from the socket with no better results. I removed the marker lights and still no change.

I see a lot of things on the internet but no real resolution.



Anyone have any thoughts or have had this issue? The 2 common denominators are the grounding system which with the wiring diagram i checked and they are tight and intact. The other would be the headlight switch, but do not see how that would cause it, with the turns and hazards off, they work fine.

Any help would be greatly appreciated.



Tim
,

:confused:

So, this is a 1994...
... with a full LED conversion. That means that you are pretty much on your own on troubleshooting, as you have a conventional wiring with electronics between and at the endpoints.

What has changed at the time it suddenly started to work differently? You stated "All worked fine...".
Go from there. Something has changed. Blown fuse, wiring etc. How does that wiring look? Solid craftsmanship or taped connections? How do(es) the electronic flasher tie into the OEM wiring? Where does it get it's signal from? Do the "hazard flashers" work as intended?

All wiring is factory, when I stated "all worked fine" I was referring to the turns and hazards when energized after the LED lights switch out. I did not try the parking or headlights when I was done. I took the Jimmy to get the state safety inspection and they told me the turns and hazards freeze when the headlights on.
I installed the electronic flashers to eliminate the possible need for resistors. I have done this same conversion on my 2008 Honda CR-V and installed resistors on all turns because of hyper flash. I also did a total conversion on our 2014 Itasca 35F motorhome and had '0' issues with no modifications needed. I am going to install resistors on the Jimmy because its easy and cheap but understanding resistors, you are slowing up, to say, the resistance of the currant, they do not increase voltage. I am only going to add them thinking in theory, that somehow through the LED, the power is going to the negative or ground somehow, so a resistor in parallel will remedy that if that is the issue.
By the way, I only know electricity and electronics because I work for a HVAC manufacturer and all our equipment have inverters on them to operate the compressors at variable voltages and frequencies, e.g. Hz.

You may want to take a look at the wiring diagram to see if any of the bulbs experience reverse polarity with the combination of headlight & turn/hazard usage. LEDs will not tolerate reverse polarity. If I remember correctly, this could be the case for the marker lights as they are on steady when the headlights are on, but flash opposite the regular flash pattern of the turn signal bulbs when the signals/hazards are on. I'm not exactly sure how this is accomplished, but given that LEDs do not function the same as a filament type bulb from a circuit continuity standpoint, that could be the rub. If it is, swapping your marker lights back out to regular bulbs as a troubleshooting step should restore functionality.

As far as the use of load resistors goes, the only thing they are good for is restoring the flash speed to normal. LEDs draw far less current than standard filament type bulbs. Using electronic flashers alleviates this concern altogether so you shouldn't need to use load resistors. Your problem is different entirely.