82IMSA

I haven't seen this discussed before.

I replaced every bulb in my car with LED's. Now when I turn on the parking lights or headlights the turn signal indicators on the dash stay on continuously.

If I remove the bulb from the front side marker lights, the indicators turn off. If I replace the LED in the front side markers with a stock bulb, the stock bulb is on but very dim.

If I replace the LED bulb in the front park/turn signal light in the lower bumper with a stock bulb, the turn signal indicator in the dash turns off.

The bulbs are inserted correctly and the sockets are not damaged. I also ran new grounds. The LED bulbs I'm using are bicolor, white for parking and yellow for turn and designed to replace the stock bulbs. Why doesn't it like a LED bulb in that location?

NINÅ

82IMSA

Wiring is the same as stock, I just replaced the grounds with new ones.

All the bulbs work exactly as they should, the only problem is with the LED's the turn indicators stay on. With incandescent bulbs they don't. Is there something I can add to the circuit so they won't come on when I use the LED's?

Tibo

iTrader: (15)

The only bulbs that use a positive circuit/wire as a ground when not in "use" are the tail light bulbs that also function as brakelight bulbs. These bulbs have one positive wire (the brakelight feed) acting as a ground when the brakes are not pressed. All of the other bulbs are simple one wire (+) and one wire (-). Our vehicles lighting circuits are wired in a very old school way. Short of re-wiring the lighting circuits I believe that the only way to wire the turn signal indicators so they don't turn on would be to wire in a diode. Something like 1 amp would be fine. The diode would only allow current to flow in one direction and should keep the turn signal indicator lights from improperly turning on.

82IMSA

I think I understand. You're saying that when I turn on the running lights the LED bulbs are back feeding voltage to the turn signal circuit, so a diode would block that current from making it to the turn signal indicators in the dash? In that case I would want to add the diode on the turn signal wire immediately behind the bulb before it branches off to the side marker or my halo on the high beam that I'm also using for a turn signal indicator. I'll give it a try and report back if it worked. Thanks!

GMan 3MT

iTrader: (4)

I think there's something else at play like Nina said since an LED IS a diode. '86 I think will be similar to this...

http://www.austinthirdgen.org/mkport...ithout_T61.jpg

The front side markers DO the weird thing using the front signal bulbs as grounds. I have a hard time wrapping my head around that too. My car isn't running, but iirc, the side markers blink opposite of the front signals when park lights are off, but with the front signals when the park lights are on, or vice versa.

*Edit* I'm not great with electrical, but I think I get what's going on... maybe.
When you turn on the park lights, normally, the marker light gets it's ground thru the front turn signal bulb. Since this is now an LED, for whatever reason, it's getting it's ground thru the dash, path of least resistance or something like that.

When you remove that bulb, you remove the path of power.

When you replace that bulb with a stock one, it's still getting it's ground thru the dash instead of a good ground thru the turn signal, so it's dim.

Replace the turn signal bulb with a stock one, now THAT is best the path to ground, so dash turns off.

GMan 3MT

iTrader: (4)

To add more, just thinking out loud. The current wiring setup requires the side marker to 'flow' both directions, which LEDs can't do.

I'm very interested in the outcome. I'm in a similar boat as you. I replaced nearly all my lights with LEDs, except the side markers, but still haven't been able to test them yet.

So maybe the diode might work. Like you said, before it branches, S106 in the diagram, so you could put it on the engine bay side of C100. Just wonder if that's enough to 'force' the ground to go thru the LED turn signal bulb that is currently failing to act as a ground as Nina said. Before you do that, I'd try turn the side marker LED the other direction and see what happens. I'm guessing it will fix the issue with the dash, but won' t come on with park lights.

82IMSA

So looking at the wiring diagram, when the parking lights are on power is fed to the side marker and front park/turn bulbs on the brown wire, and the light/dark blue wires are used as a ground for the side markers through the front bulbs. The LED bulbs will not allow that to happen.

The solution here then is to add relays wired to ground the light/dark blue wire when power isn't applied to that wire. That would be wired terminal 86 to light/dark blue from turn signal switch, 85 and 87a to ground, 87 and 30 to light/dark blue wire going to side marker bulb? Does that sound like it would do what the incandescent bulb does. I had to do a similar thing with the wire for the cruise control off the brake switch since I am using the Digi-Tails.

It appears that it works the opposite way when the turn signals are on with the side marker grounded through the front bulb. Am I going to need a relay on that circuit as well?

82IMSA

The answer to my last question is, yes, you do need a relay on the turn signal side as well. It appears to work fine with the LED bulbs, but if you put an incandescent in the side marker and turn on the turn signal it lights so faintly that you can barely see it. Apparently the LED's draw so little current that whatever ground they can get is sufficient, but not enough for a regular bulb, so to be safe you need to add a relay on that side of the side marker too. Will try this when I round up some weatherproof relays and see if it fixes the problem. Wiring would be the same except change light/dark blue to brown in the wiring instructions for the relay I described above.

82IMSA

I think I'm on the right track, but had the wiring slightly off above. You actually want to connect 86 and 87 to the wire coming from the switch, 85 and 87a to ground, and 30 to the bulb. If you do this the indicators don't come on when you turn on the lights, however, after you use the turn signal once, the indicator stays on solid until you turn the lights off. Turn them back on and no indicators until you use them again.

If you connect 87 directly to a 12V source this does not happen, however, the relays click loudly when you turn on the turn signal.

I think I'm going to try connecting 87 back to 86, but with a diode to prevent current from flowing back to 86 and the turn signal circuit. That really shouldn't be possible with 87 switched off by the relay, but apparently not? This is really weird.

82IMSA

Went back and tested the circuit after turning off the turn signal, and somehow it has about 4V bleeding back up the wire to terminal 30, then across to 87 which when connected to 86 allows it to get back to the indicators and apparently also trigger the relay so it never switches back to 87a to ground the circuit properly.

I'm going to assume that if I add a diode the relay is going to switch properly, and the click will come back, so might as well save the money on the diode and just wire 87 directly to the battery. It only clicks when the turn signal is on, the clicking of course being the switch inside the relay operating.

If you have this issue and want to use the LED's, connect 86 to the wire coming from the switch, 87 to a 12V source, 85 and 87a to ground, and 30 to the wire going to the bulb. You will need 2 relays on each side marker light, one on each wire as described.

NoEmissions84TA

iTrader: (1)

Did you replace your flasher with the LED version?
Also, I thought that some of the better name-brand LED conversion bulbs incorporated resistors, so that they continue to "look" like incandescent bulbs to the circuits.

84 1LE

iTrader: (9)

85 & 86 should be the low side (pwr)of the relay, with 87-30 your hi side (led).Are your tri color leds 3 wire? If so, that could be the issue (guessing).A relay is the better way to go though.With a relay you shouldnt need a LED flasher, but it wont hurt anything if you use one.Some LEDs are non directional, meaning you can plug them in any way, but normaly its pos-pos & neg-neg.This is how i wired mine up, but you will need a relay for every lamp, 4 in my case.On post 19 is my schematic.

https://www.thirdgen.org/forums/auto...de-marker.html

82IMSA

I replaced both the turn and hazard flashers with LED versions, and they blink fine.

The problem here is the circuit grounds through the unused filament in the park/turn signal bulb in the front bumper. When you replace the 1157 bulbs with LED's they don't ground properly and ground through the turn signal indicators in the dash when you turn on the lights causing them to stay on solid.

The relays I added ground the side markers properly so you don't get current running back through the indicators.

82IMSA

You solved a different problem. My LED's in the side markers are non-directional, so it doesn't matter how I install them. The LED's in the front are 3 wire, and don't ground the circuit like the stock 1157 bulbs do. The relay setup I described above solves the problem of them trying to ground through the turn signal circuit when you turn the lights on which causes the indicators in the dash to stay on.

83 Crossfire TA

iTrader: (2)

This is driving me crazy, can you draw out the circuit so I can see what is going on?

82IMSA

It's already fixed. The side markers ground through the front running light bulbs, and when you put LED's in that location they don't allow that to happen, so they wind up grounding through the turn signal switch causing the indicator light on the dash to come on. Wire a couple of relays as I described above, and the problem is solved. Or just don't use LED's in the front running lights...

NoEmissions84TA

iTrader: (1)

Yes 83 Crossfire TA, it is because of those dual filament bulbs.