eca1987

Greetings Fellow LS!1 Tech Members

I have a 1998 LS1 Trans AM Convertible. Recently both of my DRL's/Turn Signals on both sides stopped working. The Turn Signal Lights do dimly illuminate when the headlights are on but do not work when lights are off as DRL's or flash when the turn signals are activated. Completely dark. The Green Right and Left Turn Signal indicators on dash do blink either left or right when actuated and appropriate left or right rear tail lamps do flash but neither front flash left or right,

I had recently done a full LED swap and did replace the Turn Signal Flasher with an electronic one although I did not replace the hazard flasher as was hidden behind a plastic piece/wires under the the dash/steering column and not immediately accessible. Ironically when I turn on the hazard flashers, for which I did not replace the thermal flasher with and electronic one, the rear tail lights do flash but again it's "lights out" in the front.

Could this possibly be the sockets assuming both are out at the same time but just for DRL/Turn Signal function as power does get to both lights for dim illumination when the headlight switch is on but never illuminate in DRL mode or when turn signals are actuated?

Another thing I am confused about DRL's, I have always assumed I had them but were they an installed option or did every 1998 Firebird have them?

Also, when I downloaded the original 98' Owners Manual in.pdf format and here is what is says about DRL's:"Daytime Running Lamps (DRL) can make it easier for others to see the front of your vehicle during the day. DRL can be helpful in many different driving conditions, but they can be especially helpful in the short periods after dawn and before sunset.

For Canadian vehicles, a light sensor on top of the instrument panel automatically turns the headlamps on, so be sure it isn’t covered.

"The DRL system will make your front turn signal lamps come on when:

• The ignition is on,
• the headlamp switch is OFF,
• the parking brake is released and
• It s bright enough outside (on Canadian vehicles).

When the DRL are on, only your front turn signal lamps will be on. The taillamps, sidemarker and other lamps won’t be on. Your instrument panel won’t be lit up either.

For Canadian vehicles, when it’s dark enough outside, your front turn signal lamps will go out and your headlamps will come on. The other lamps that come on with your headlamps will also come on. When it’s bright enough outside, the regular lamps will go off, and your front turn signal lamps will come on."

But hen it goes on to read:"On a non-Canadian vehicle, the DRL have to be turned on manually when you need them. On Canadian and domestic vehicles, when the headlamps are turned on, the front turn signal lamps will go out. When you use your turn signals, the front turn signal lamp and the taillamp on the desired side will flash

"As with any vehicle, you should turn on the regular headlamp system when you need it"

So, which is it? Do the DRL's come on automatically when the: "Ignition is On", "Headlamp Switch is Off" and "Parking Brake is Released? Or, do they somehow have to be turned on "Manually" on non-Canadian when you need them as stated in the manual. If so, how are they turned on manually. IS the Parking Brake really involved and has to be released? Very confusing.

FYI, As a test, I did try re-replacing the LED turn signal bulbs with the old incandescent two filament bulb but I still get the same behavior and put the LED's back..

So, Could this be?

• Bad Bulb Sockets
• The DLR Control Module? if I have one
• Issue With The 11 Wire C216 connector
• Something else?

By the way, does the BCM have anything to do with the Turn Signals

What steps should I take to diagnose/resolve this issue?

Your expertise/recommendations are greatly appreciated.

Thanks,

Big Ed
eca1987

wssix99

iTrader: (5)

This would indicate some sort of short circuit in the bulbs, harness, or sockets.

Before you started all this, did everything work?

What model flasher did you put in? Are you sure you replaced the turn signal flasher and not the hazard flasher? (You WILL need to change both.)

WhiteBird00

iTrader: (4)

Let's start at the top. Bear with me if this becomes a really long post (you asked for it ).

Your front lamps have two filaments that operate independently - a bright one for DRL and turn signals, and a dim one for parking/running lights. They are two separate circuits so it is quite possible to have the bright filament burned out while the dim one still works. Or, the bulb could be okay as in this case (you already swapped bulbs without changing the symptoms) but the socket contacts could be damaged or corroded or the wiring could be damaged. So that is one of the first things to check.

It would appear that there is a typo in the owner's manual you downloaded. The part that says the DRLs must be activated manually should say that in non-Canadian Firebirds, the headlights must be activated manually. All 98-02 F-bodies have automatic daytime running lights which activate with ignition on, lights off, and parking brake off. All 98-02 Camaros also have automatic headlights that go on when it gets dark. However, only Canadian Firebirds come with automatic headlights - US models have to turn on the headlights manually. This is to meet Canadian law but not annoy US owners with headlights flipping up and down all the time causing premature wear.

As previously mentioned, it certainly could be the front sockets. It could also be the DRL module (yes you have one). Connector C216 is not the problem since it would only affect the turn signals and not the DRLs which are independently powered through the DRL module.

You will have to test the system using a multimeter or test light. You have a choice of starting at the lamps or behind the radio at the DRL module. Personally, I would start at the DRL module since it can be reached without crawling on the ground. Pull the radio surround trim (it's just held on with push clips) then remove the four screws holding the radio and pull it out far enough to unplug the connectors on the back then remove the radio. You will see the DRL module mounted to the defroster duct at the back of the radio opening. It is a black box about the size of a deck of cards with two connectors - an 8-pin black and an 8-pin blue. Leave everything plugged in and probe the back side of the wires in the connector to check the following conditions:

- turn on the ignition, release the parking brake and check for power on either one of the output wires - either one of the solid blue wires (no stripe) in the black connector. If you see power then you know the problem is between the DRL module and the lamps... either the wiring or the sockets.

- if you don't see power, check the pink wire in the blue connector. I expect you'll find power there but if you don't, check your GAUGES fuse in the dash fuse panel. You would have gauges not working if that fuse was burned out so it's probably okay unless you neglected to mention a gauge problem. If the fuse is okay but you don't have power at the DRL module then you have a break somewhere in the pink wire between the fuse box and the module.

- if you do see power there then you know the DRL module is the problem. If you want to confirm that, turn on the turn signals and check for flashing power on the pairs of blue wires. There is a dark blue pair and a light blue pair. The dark blue is right signal and the lighter blue is left signal. Each pair has a white striped wire which is power input from the turn signal switch and a matching plain wire which is output to the front lamps. So if you find flashing power on the white striped wire but not on the matching plain wire then you've confirmed that the DRL module is bad.

eca1987

Question WhiteBird00, you wrote in your response above

Each pair of blue wires has:

• plain wire which is power input from the turn signal switch and a
• matching blue with white stripe wire which is output to the front lamps.

However, in a previous Post on 4-10-2007 to @SenseiSimpleton you cited the Black Connector Pin Out was:

Connector C1 (8-pin black)
A - Orange - power from TAIL LPS fuse
B - Light Blue - left front DRL/turn signal lamp output
C - Dark Blue - right front DRL/turn signal lamp output
D - Red - power from headlight switch
E - Light Blue with White - left turn signal input from turn signal switch
F - Yellow - power out to headlights via highbeam switch
G - Dark Blue with White - right turn signal input from turn signal switch
H - Brown - parking/running light output

I interpret from that, that:

Plain Blue = Output From Turn Signal Switch
With White Strip = Input From Turn Signal Switch

Seems to me they are opposites. Which one is right or maybe I am not reading it correctly.

Sorry, I apologize, I am new to this.

Just want to make sure before I start probing

Thanks,

Ed

WhiteBird00

iTrader: (4)

Sorry, my mistake. I was going from memory instead of referring to the schematics. I have a good memory but it's short.

You are correct - I had them reversed. The white stripe wires in each pair are the input from the T/S switch and the solid color wires are the output to the front lamps.

wssix99

iTrader: (5)

^ I would remove the LED bulbs before probing. We often see odd bulb issues cause these problems and/or shorts.

WhiteBird00

iTrader: (4)

Agreed. That was my first thought as well except that he had already tried reinstalling the original incandescent bulbs and the symptoms persisted.

wssix99

iTrader: (5)

Yea. As a best practice, I'd still take them out. Just in case. (remove complexity from the situation wherever possible)

I would still like to see the part numbers involved here - particularly the flasher.

We should also mention that the flasher don't really "flash" all the lights... When the flasher actuates, it flashes the rear bulbs and also sends a flashing pulse to the DRL module. The DRM module has it's own relays that act in opposition to the flasher. (The DRL module turns the bulbs "off" with each flash - because they are already on for the DRL mode.) So, as the rear bulbs go on, the fronts go off.

^ This doesn't mean that the DRL module is bad - it's just something to keep in mind as all this is being debugged. If a flasher is bad, then it could cause the rear bulbs to freeze on but the front bulbs to freeze off at the same time. (So, in this mode, the front bulbs being "off" would be good and proper.)

WhiteBird00

iTrader: (4)

Actually, the DRL module doesn't flash the front lamps. There are two internal relays in the module - one for left and one for right. These relays each have two inputs - an ignition power input from the GAUGES fuse and a turn signal power input from the T/S switch via the corresponding white stripe wire. When the logic circuit sees flashing power on the T/S input wires, it flips the appropriate relay from ignition power input to T/S flashing power input so that the flashing power gets passed through to the corresponding front lamp.

Similarly, when the logic circuit gets input that the headlights are on, it flips both relays in the same way (to the turn signal position). This turns the bright filament off (there is no power from the T/S switch at rest) and leaves the dim filament to illuminate for running lights. Using the turn signals while the headlights are on will not flip the relay because it's already in the right position so the flashing power is passed straight through the relay to the lamp. That's why the front lamps alternate bright and dim, rather than bright and off, when the headlights are on.

The logic circuit incorporates a timer delay before returning the relay to its rest position (DRLs on) so that it isn't switching back and forth between flashes. That's why the turn signals always end on an off cycle and there is a short delay before the DRLs return after cancelling the signals. This configuration keeps the front lamps flashing in sync with the rear lamps rather than opposite to them.

Power path for right turn signal.

eca1987

Thanks for the great advice gentlemen. Although I have not yet had time to start testing, tomorrow my intention is to cut off the old sockets and replace with new ones just to eliminate them as a variable. What I was going to do before splicing in the new sockets was to first test for current on the blue wire, I am going to assume that if I turn the ignition on, release the parking brake and make sure the head lights are off, if the DRL Module is working, I should see current at the blue wire while touching the ground wire. If there is current I should be able to actuate the turn signals and see flashing current. If it works for both lights then I would assume splicing in new sockets I should be good to go. If there is no current, can I then move to probing the DRL Module without first re-attaching the new sockets. Let me know if that will work or should I splice in the new socket first. I will remove the LED bulbs so as to remove them as a variable.

Also, although I appreciate the concern about the replacement Flasher is used, the fact that I do not even have working DRL's would seem to trump the flasher for now,

I'll let you know what I find out.

Thanks again,

Big Ed,
eca1987.

WhiteBird00

iTrader: (4)

Yes, that's quite correct. That was the option for testing that I wouldn't choose only because I'm approaching retirement and don't feel like crawling around on the ground to get to the front lamps. But it is a quite valid method of testing. Each front socket has three wires - blue for DRL/Turn signals, brown for parking/running lights, and black for ground. Testing for steady power (DRLs) or flashing power (turn signals) on the blue wire at the lamps will allow you to diagnose whether the sockets are the problem or it's something further upstream like the DRL module.

There are kits available that allow you to replace the sockets without cutting and splicing the wiring. I couldn't find the link quickly this morning (haven't finished my coffee) but wssix99 knows where to find them.

wssix99

iTrader: (5)

I don't have ready access to my schematics right now and my online ones have gone wonky. The flasher input goes to input "F" on the solid state module, which then controls the relay you highlighted. The end result of the relay actuating (I recall) is that the front lights flash out of phase with the rears. (This is only important if one is probing and the flasher is frozen.)


Yea. You don't want to do this. (I've had my coffee.) Here's the link and this is the way. - https://ls1tech.com/forums/wiring-st...-required.html


Please share the model numbers with us, for the bulbs and flashers. You could be chasing down multiple issues and if we can see the parts you are installing, it will save us all a lot of effort. Electronic flashers are pretty basic and tolerant. Bulbs - not so much.

WhiteBird00

iTrader: (4)

I really hadn't planned to get so deep into this since I'm sure Big Ed isn't concerned about the background details but I find it an interesting discussion so forgive me for continuing.

Although pin F on the DRL module comes from the TURN B/U fuse, it is not flashing power via the flasher and turn signal switch - it's just an ignition controlled power feed. The flasher and T/S switch are fed from the splice at S207. The turn signal flashing power input to the DRL module comes on circuits 1414 and 1415 (the blue with white stripe wires) at the bottom of the schematic. The two relays for left and right lamps can only switch between that flashing power and a direct ignition power feed. As you can see in the schematic, with the relay in the position shown, flashing power from the T/S switch is passed in through the DRL module, through the relay, and directly out to the front lamps. There is no need for the logic circuit to do anything but keep the relay in that condition until the signals are turned off. Then the relay flips back to the other position to allow steady ignition power to flow through to the lamps for the DRL function.

Unfortunately, I no longer have my Trans Am so I can't go out and check if the front flashes in sync or opposite the rear lights. But I'm pretty sure it's in sync from what I remember of installing and testing sequential signals in the rear. Perhaps someone can have a look and let us know for sure.

eca1987

Again, incredible advice and detail here especially for us novices. I will give the dismantle and re-assembly a try. Seems prudent that I test the pulled out wires for current before i plug them back in to the new socket to make sure there is not a break in the wire. That is of course, assuming there is power there in the first place.

I will let you know how it goes.

BigEd
eca1987

wssix99

iTrader: (5)

Indeed. I should have better access to my schematics over the weekend. I'd like to dig in and look closer.


I'll check eventually. My Firebird is up in the air on a lift while I winterize some jet skis. (Then they go in the air to hibernate.) I'll get on a ladder, if I need to.

eca1987

Well yesterday I finally had time to put the car on the ramps. Got under there and dismantled and removed the old socket on the Drivers Side. Turned on the ignition and released the parking brake and then metered the Blue DRL/Turn Signal and Brown Courtesy light wires and both had power. Used the link WSSIX99 had provided and disassembled my new socket removing the 3 wires they provided, got back under the car, inserted the 3 exposed wires, blue, brown and black; ground, into the new socket, snapped in the core of the socket and viola it all worked. DRL''S work, turn signal flashes, courtesy light works with parking lights and headlights. Even the hazards flash despite having never changed out the hzard Flasher relay.

So today I will try the passenger side which I expect should be the same. Was not confident that this alone was going to solve the problem as the courtesy lights worked on both sides but not the DRL'S or Turn Signals. Thought for sure it was the DRL module. All a pleasant surprise with no splicing required, Oh yes, I forgot to mention I used the LED bulb too.

I'll let everyone know what happens on the passenger side.

Big Ed
eca1987

wssix99

iTrader: (5)

Good progress!

The original flasher is less sensitive than the turn signal flasher because it's used less and is driven by more bulbs/power. Not surprising, but I'd still change it when you can.


The DRL and Turn Signal share one filament (and one contact on the bulb socket) and the Parking lights are a separate filament/contact. This shared filament usually helps us sort out problems between the flashers, DRL module, and switches. When nothing works, we look to the wiring/shorts/bulbs/sockets.

eca1987

I have wanted to replace the Hazard Flasher as well as I have already replaced the Turn Signal flasher. I can hear the old hazard flasher click when activated but it is hidden and to the left of the relays in the pic below and I am not sure how to get at it. Any ideas.

Let me know

Big Ed
eca1987

wssix99

iTrader: (5)

The hazard flasher is clipped to the underside of the dash on the left side, just like the turn signal flasher, which is clipped on the right side. Remove the lower IP panel and its up and behind. (Not visible from the cabin.)

Those relays you are showing in your picture look aftermarket.

eca1987

Well, I finally finished the passenger side. Buttoned everything up and you are not going to believe this. Now the car will not start. No Dash lights does not even crank. Can this really have anything do do with the turn signal socket replacement? Any ideas would be greatly appreciated. One step forward, two steps back. So frustrating. By the way, everything in the car works, radio, headlights, door locks, I metered the battery, 12.5 volts. I here a click when I turn the key but nothing else. As far as the red light on the dash is concerned, When I lock the car with the key fob the red light on the dash flashed intermittently . When I unlock with the key fob the light goes out. When I insert the key with the door open the chime sounds but when I turn the key, crickets. No crank, no dash lights, just here a small click under the hood. Red security light do not light or blink.

Well a little detective work and I figured it out. My newly replaced socket must have a short. When I released the parking brake earlier to test I did not notice it blew fuse #9 Garages. Without a good Fuse #9 car will not start. Replaced fuse, Parking Brake on., car started, released parking brake, fuse blew. Must have a short in my new socket. Will trouble shoot tomorrow..

Big Ed
eca1987.