A while back when I redid my interior, I put in a stainless steel faceplate for my speedo/tach cluster. When I did that I put in led lights to replace the stock turn/hazard, hi-beam, and warning indicators. I have 2 green led bulbs, a blue, and an orange. I got everything from CIC and had no issues with anything. Now, after doing my headlight upgrade (I did speeddirect's H4 bulb conversion and Ford probe actuators) and changing all my bulbs to LED (turn/brake/markers/interior etc) I'm having a strange issue. My green indicators for the blinkers work fine when using the turn signals or hazards, but they also illuminate when I turn the headlights on. It's mostly just a nuisance, but at night they are very distracting.

The only thing I can come up with is somehow the headlight circuit is back feeding the indicators somehow? Looking at my diagram the 2 green LEDs get power from the lt.blue and dk.blue wires originally run to the printed circuit (dark blue is the R signal, light blue is L) If you follow the diagram these blue wires also feed power to the turn markers and obviously the turn signal/parking lamps. Is it possible that the parking lamps, which come on with the headlights but also serve as the front turn signals could be backfeeding now that they are LED and a lower draw? If so, how can I correct this?

While I was for a response I tried throwing the old incandescent bulbs back in the parking lamps to see if that did anything. When I turn the headlights on now only the right turn signal indicator illuminates.... So it must have something to do with the LED bulbs I'm now using for the exterior lamps. Electrical gurus, how do I fix this?

Any help is appreciated!

NOTE: The dash indicators are all grounded to the body under the dash. I tried moving them to a different body ground and that made no difference.

 

Try removing the led's from the front marker lights. Due to the way gm wires the markers and front signals to blink alternately when signalling, the led bulbs won't function the same. Basically the marker light reverses polarity when using the signal as opposed to the marker light. Led's are diodes which are polarity sensitive.

 

LED AKA Light Emitting Diodes-

Diodes by definition only let current flow in one direction.- incandescent lights go both ways

Here's a solution-add a ground to the market light w/ two lights.

 

I tried to get d_boy to do this years ago, but he couldn't comprehend it.

 

Thanks for the replies everybody.

Richard, how would I ground that socket. I haven't gotten a chance to look at it yet, but how would you go about adding a third wire to a two wire socket?

 

That's Interesting, I have the same problem, but I don't have LED installed. It's just as you described except min is intermittent, sometimes when you turn on the headlights the right turn indicator comes on and sometimes both indicators come on. Over the last while it is less frequent but still happens every now and then. I play with the connectors for the headlights and sometimes it goes away and sometimes it doesn't. I do believe it is a grounding issue in one of the connectors.

 

Thanks for all the input thus far. I tried taking the 194 LEDs out of the front side marker turn signals and replacing them with the incandescent, leaving the LEDs in the front parking lamp turn signals. This solved the problem, however having an electronic flasher the incandescent 194s don't work at all (but the signal indicators no longer illuminate with the headlights on)

So, how do I fix this? The side marker 194s need to be grounded correct? How do I add a ground to a two wire socket?

Thanks!

 

Bad contacts in the front marker sockets gave me the same illuminated blinker issue. Easy check. Cboyd that might explain why it's intermittent for you.
Subscribed, never could get the front and side marker to work correct with LEDs
Nick

 

Simply use two LED lights and add a ground.

If the housing is plastic- you can mod it to accept an 1157 socket-as that's essentially two bulbs in one...

Could also put a strip LED inside the housing- sort of like this-





Front- I used a Halo for parking- and a COB LED for turn

 

He's saying to replace the 1-filament/2-wire socket with a 2-filament/3-wire socket or at least with a 3-wire LED bulb arrangement. This creates separate independent marker and signal functions the same as the 1157 bulbs have.

I think the marker bulb is a little single filament bulb 168? and I have no idea where you'd get a dual filament socket or LED bulb to replace it without making something up.

I suspect a little bridge rectifier connected into the marker light wires would also do it, but I'm not positive and have no way to test.

 

Here you go- a little better description.-might be a little easier.

Just google "194 socket"- SuperbrightLED -Summit- Autoparts stores have these- very inexpensive.

You will have two lights instead of one.


You'll have to mod the housing- I'm thinking it's plastic- just simply drill a hole and file for the tabs to fit the second socket then wire as below-

 

Nice drawing Richard. Be aware that these female sockets typically lose an LED every 28 days.

 

Thanks!!!

Now you say 28 days...Is that because they are female sockets!!!

With the lifespan of LEDs- could just put a dab of silicon on them.

 

Perfect Richard, thank you!

So basically I have the option above with dual 194's in each marker, or modify the housing to accept an 1157 and install a new 3 wire socket? Either way I'll have to modify the socket, so if that's the case I may go with the 1157, assuming there's enough room in the housing to fit it. Thanks for the diagram, I'll update with what I end up doing and how it works out!

 

I was trying to be funny given the shape of your diagram. Fail.

 

Ok...OK...now that I look at it....I'm not going to ask-

But last time I had sex education was almost 30 years ago in the 9th grade.... Come to think of it- the 9th grade was the best 4 years of my life!!!

I'm thinking you might want to take this test- http://theinkblot.com/

Let us know the diagnosis...

 

Now that is funny

Oh dear, the diagnosis is that I must be French.

 

Richard, I got a chance to pop out one of the marker light/cornering lamp housings today to see what I could do to modify it. As I was afraid, the housing doesn't really have enough room to accommodate adding a second 194 or converting the current 194 to an 1157. There's not enough depth to fit a bigger bulb, and the housing tapers off right after the current 194 so there isn't enough depth to fit another one... see the pictures below.









Unless there's another way that I'm missing?? If not, I'm thinking the simplest solution at this point would be to remove the marker lights from either the turn signal or parking lamp circuit...? I would assume this would solve the problem by eliminating the path for it to backfeed into the other circuit? I'd just have to decide if I want to make it a permanent turn signal or marker light, I'm thinking turn signal. This should work right?

 

Ok...plan B-

Look at these 7443 bulbs- twin filament- looks small enough-

https://www.superbrightleds.com/more...rofit-car/797/



Sockets-

 

Those could work! I'll check them out, thanks!