LED conversion 1990
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From: Washington State
LED conversion 1990
Ok! So I am changing out my halogen lights on the exterior and I have my everything in except my headlights and my break lights.
Now for the questions
I changed out the turn signal flasher relay, and after I closed everything up, I thought "Wheres the hazard flasher relay?" I cant find anything about it for the 90 and up.
SECOND
When my headlights are on, my turn signal Indicator lights are always running, when they didn't before the LEDs. What can I do to fix that.
Third!
Are the front and side blinkers supposed to alternate? I've found people explaining the principle about it, but they don't say if the are supposed to or not.
Finally
when I decide on what I want to put in for my headlights, how do i fix the fog lights not turning on with the headlights on. I want them to work like they are supposed too, on with dims, off with brights.
Now for the questions
I changed out the turn signal flasher relay, and after I closed everything up, I thought "Wheres the hazard flasher relay?" I cant find anything about it for the 90 and up.
SECOND
When my headlights are on, my turn signal Indicator lights are always running, when they didn't before the LEDs. What can I do to fix that.
Third!
Are the front and side blinkers supposed to alternate? I've found people explaining the principle about it, but they don't say if the are supposed to or not.
Finally
when I decide on what I want to put in for my headlights, how do i fix the fog lights not turning on with the headlights on. I want them to work like they are supposed too, on with dims, off with brights.
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Joined: Jul 2022
Posts: 79
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From: Washington State
For "Finally": Obtain a socket pigtail and a 168 light bulb. Wire one side to the lt green high beam wire. The other to ground. Only one side needs the 168. Put the 168 behind the headlight bulb in the pod. The fogs will operate as desired, the way they do now. (Not an original thought. I think this is in a Stickey in the tech article thread, not sure. But it works.)
Second and Third: Yes they are supposed to alternate. The front side marker operation gets all screwed up with LEDs in everything. LED in the side marker is why the green arrows are on. The simplest method to restore some normalcy is to cut the lt blue (left side) and dk blue wire (right side) marker and connect the bulb-side wire directly to ground; the green arrows won't be on either. The side marker will be on with tail lights, but won't blink or alternate with turn signals. The only way to retain the OEM side marker operation is to use the load resistors on front turn signals and the tail light circuit, and retain incandescent side marker bulbs. 3 resistors.
Hazard flasher on the 90 is under the RH dash, way back against the firewall, above the carpeted hush panel above the passenger's feet.
EDIT/ADD: I've never done this, but it would work for the Hazard Flasher. An EP27 LED flasher has 5 wires. It is intended to be used for both turn and hazard. The turn signal flasher is on the driver side, you know where it is. There is an inline connector at the base of the steering column for the turn signal switch. There are two brown wires, one of them is the output of the hazard flasher. Terminal "K". (The cornering lights have a brown wire in terminal "A" which is o0n the end, which is hot with tail lights on. Wrong wire.) Cut the terminal K wire, and connect the hazard output of the EP27 to the side that goes into the steering column. For the Battery input for the EP27 tap the orange wire at the brake light switch. This is the fused side of the hazard flasher, so the same circuit.
It can all be done on the "easy" side of the dash to get to. If you already have a 5-wire LED flasher, there should be the 2 hazard wires ready to connect.
Second and Third: Yes they are supposed to alternate. The front side marker operation gets all screwed up with LEDs in everything. LED in the side marker is why the green arrows are on. The simplest method to restore some normalcy is to cut the lt blue (left side) and dk blue wire (right side) marker and connect the bulb-side wire directly to ground; the green arrows won't be on either. The side marker will be on with tail lights, but won't blink or alternate with turn signals. The only way to retain the OEM side marker operation is to use the load resistors on front turn signals and the tail light circuit, and retain incandescent side marker bulbs. 3 resistors.
Hazard flasher on the 90 is under the RH dash, way back against the firewall, above the carpeted hush panel above the passenger's feet.
EDIT/ADD: I've never done this, but it would work for the Hazard Flasher. An EP27 LED flasher has 5 wires. It is intended to be used for both turn and hazard. The turn signal flasher is on the driver side, you know where it is. There is an inline connector at the base of the steering column for the turn signal switch. There are two brown wires, one of them is the output of the hazard flasher. Terminal "K". (The cornering lights have a brown wire in terminal "A" which is o0n the end, which is hot with tail lights on. Wrong wire.) Cut the terminal K wire, and connect the hazard output of the EP27 to the side that goes into the steering column. For the Battery input for the EP27 tap the orange wire at the brake light switch. This is the fused side of the hazard flasher, so the same circuit.
It can all be done on the "easy" side of the dash to get to. If you already have a 5-wire LED flasher, there should be the 2 hazard wires ready to connect.
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From: Washington State
One other suggestion: Leave your third brake lights incandescent. This circuit is also an input to the ABS system. With LED bulbs, the ABS will think the brake is applied at all times. It may set a code for "brake applied at all times". (It can't "see" ground through the one-way polarity of the LED.) In a 90 which doesn't have TCS I don't think this is an operational issue, and may or may not set the mentioned code. But in a TCS 92-up, it can be.
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From: Washington State
Second and Third: Yes they are supposed to alternate. The front side marker operation gets all screwed up with LEDs in everything. LED in the side marker is why the green arrows are on. The simplest method to restore some normalcy is to cut the lt blue (left side) and dk blue wire (right side) marker and connect the bulb-side wire directly to ground; the green arrows won't be on either.
but when I ground the light side of the blue wire, the blinker doesnt flash, but DRL work. And when i ground the other end, the green arrow disappeared but then when I engaged the blinker, it blew the fuse.
Is there anything else you can think of?
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From: Washington State
"DRL"? Your 90 has T61 (RPO for DRL)? Is it a Canadian Export Model? (There's an RPO for that too, but I don't recall what that is at the moment.)
If you don't understand what is happening, why things do what they do with LED which ARE POLARITY SENSITIVE, how the circuits are configured and how they change when they become uni-directional, you should probably not be doing these modifications. Especially with the C4 circuits of T61 DRL, if your car has T61.
If you don't understand what is happening, why things do what they do with LED which ARE POLARITY SENSITIVE, how the circuits are configured and how they change when they become uni-directional, you should probably not be doing these modifications. Especially with the C4 circuits of T61 DRL, if your car has T61.
But with the 1157 bulbs they can only go in one way due to the ridges.
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From: Washington State
Has nothing to do with it.
There are four possible states for the front side marker (SM) bulb:
1: No power on either wire. the SM is OFF.
2: Power ON the Turn Signal (TS) wire (lt blue or dk blue) Park Lights (PL) (brown wire) OFF = The SM flashes in unison with the TS. (The SM bulb "sees" ground through the park light filaments.)
3: Power on the PL wire, but no power on the TS wire = The SM is ON. (The SM bulb "sees" ground through the TS filament.)
4: Power on the PL wire (see above) but the TS also comes ON. The SM "looses" its ground when the TS wire is powered, the SM goes OFF, this is why it "alternates" with the park lights on.
Note that 2 of the states require that the turn signal bulb filament conducts from the blue wire to ground. An LED does not conduct in this direction. The way the bulb is installed in the socket has nothing to do with this. If you don't understand these basic principals, and why the 4 states above function the way they do, you should probably put the incandescent bulbs back.
There are four possible states for the front side marker (SM) bulb:
1: No power on either wire. the SM is OFF.
2: Power ON the Turn Signal (TS) wire (lt blue or dk blue) Park Lights (PL) (brown wire) OFF = The SM flashes in unison with the TS. (The SM bulb "sees" ground through the park light filaments.)
3: Power on the PL wire, but no power on the TS wire = The SM is ON. (The SM bulb "sees" ground through the TS filament.)
4: Power on the PL wire (see above) but the TS also comes ON. The SM "looses" its ground when the TS wire is powered, the SM goes OFF, this is why it "alternates" with the park lights on.
Note that 2 of the states require that the turn signal bulb filament conducts from the blue wire to ground. An LED does not conduct in this direction. The way the bulb is installed in the socket has nothing to do with this. If you don't understand these basic principals, and why the 4 states above function the way they do, you should probably put the incandescent bulbs back.
I got it working, I needed load resistors so the indicator lights on the cluster work properly
Thank you for the help though
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Joined: Jul 2022
Posts: 79
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From: Washington State
I got it working, I put in load resistors, it was because the LEDs in my turn signals don't draw enough power and so my indicator lights in the cluster were showing when the headlights on. It thinking there are bad bulbs
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