Replacing Turn Signal Lamp in Left (Driver Side) Front Headlight Assembly


Tomcat

GT Owner
May 23, 2013
937
North Carolina & Perdido Key
Agreed...Remove the wheel, pull all the plastic mushrooms, move lower lip of splash guard away from top of shock and rotate it an inch...the outer lip comes free and then just peel the leading side back to reveal the headlight/turn signal.
MAD did all the work!
Getting the little push pins out (and re-attaching the splitter) too most of the time! Having a lift is pretty handy!
 

bonehead

GT Owner
Mark II Lifetime
Aug 18, 2012
2,777
Houston, TX
My passenger side turn signal has been intermittently working for months, so I finally decided to have the guys at M2K pull the liner and change the bulb. Apparently, the old one looked fine but the contacts in the socket looked a bit spread out. They adjusted those, had a new bulb coated with dielectric grease and installed.....didn't work. Gave the headlight a good tap and it came back on. Annoyed is an understatement.
 

Waldo

GT Owner
Mark IV Lifetime
Sep 7, 2005
756
Fort Worth, TX
FENZO, I'd bet money that if you turn on the turn signal and then get out and slap the headlight a few times with an open hand, it will start working again.
Although this thread is quickly approaching its two-year anniversary, I found out this afternoon that the information listed within is no less valuable. Today my passenger side turn signal bulb decided to quit. After a quick review of the Forum, I found Kendall's advice to give the headlight assembly a little love tap. Sure enough, my right turn signal bulb now understands who's boss in the garage and decided to start working again.

Once again, many thanks to Kendall and all who contribute to the Forum.

Best Regards,
 

otis

GT Owner
Mark II Lifetime
Nov 13, 2011
347
Stillwater, MN
Thanks I was hoping it was easy. What about the tabs holding on the air dam? Are they reusable or do I need to get a few of them to replace the air diffuser? I thought I read they had to be broken off and replaced.

Rob
 

fjpikul

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Jan 4, 2006
10,403
Belleville, IL
No, the tabs are not broken. Just take down all the screws and it will come off easily.
 

BlackICE

GT Owner
Nov 2, 2005
1,415
SF Bay Area in California
No, the tabs are not broken. Just take down all the screws and it will come off easily.
and 2 push pins on the back outside corners.
 

richardhead

GT Owner
Sep 19, 2006
169
Hello, Everyone…

There has been some discussion on the forum regarding the intermittent operation or failure of one or both of the two front turn signal bulbs. The basic thrust is how to access the units for replacement, but it turns out there are actually a number of things to attend to when working with these bulbs.

My driver’s side front turn signal in the headlight assembly started going intermittent on me a few weeks ago. Symptom was a fast clicking sound when the front bulb was not flashing, then back to normal clicking when it did flash. I thought I had a broken turn filament that reconnected when it was jostled, since the running light filament in the same bulb seemed to work fine.

It turns out, this issue embraces a number of “challenges/fixes” if one is to correctly address the entire problem scenario. The issue with the bulb is one of (1) how to get it out as simply as possible, (2) why did it malfunction if the filament just didn't burn out, and what to do to address either (2A) the filament burnout or (2B) another cause...when replacing the bulb. In addition, (3) the type of bulb used for replacement will make a difference in the long term viability of the overall solution.

Right up front I want to credit “Shadowman” and “nota4re” for their help. Shadowman sent me a photo of the back of the headlight assembly for use in locating the turn signal bulb (I’ve asked Bill to post this photo if my copy from him doesn't upload), and “nota4re” voiced an observation on oxidation of bulb contacts in one of his posts on the subject, which was right on the money with my circumstance…and I now presume is an issue with all the cars’ headlight assemblies. Thank you, Bill and Kendall, for your help.

(1) The driver side front turn signal bulb can be removed without removal of the wheel and fender liner. The front spoiler should be removed first (simply break off the head of the flat push-in retainer; you’ll need to get a new plastic push in retainer when reinstalling the spoiler, or you can use the screw-in type of plastic retainer which is easily removable without breaking off the head), then the screw-in retainer on the lower left side of the driver side fender holding the fender to the outer body piece. The body piece should be edge wrapped with a cotton wash rag and pulled down and away from the car, gently. Then the fender liner lower left lip can be pulled up, forward and over the outer body piece protected by the wash rag. Roll a towel into about an 8-9” long roll and slip it between the fender liner front edge and the body panel piece to create a larger opening which will stay in place (thanks to the towel) to allow more room to reach up with your right arm from below. Its pretty easy to see how to do this when you try it.

(2) You can then reach up to the far left behind the headlight assembly and feel the bulb retainer. It has a plastic sheathed wire connected to it, and a thin plastic “fin” at the bottom part of the retainer. It isn’t easy, but patiently and carefully twist/work the retainer counter-clockwise and it will turn out. You can then drop the assembly down and remove the bulb. Reverse the procedure to re-install after replacing the bulb. To align the retainer when replacing it, remember the “fin” is vertical when properly installed. So to find the spot to insert the retainer, the “fin” must point to the left of vertical. Then turn the receptacle clockwise until the fin is vertical. A little dielectric grease on its contact surface will make it turn in more easily than it turned out.

(3) Before replacing the bulb, check the one you took out. Mine did not have either filament burned out, but had oxidation on the contacts. If the bulb had a burned out filament, the following process should also be followed: Use a new bulb, even if yours merely had oxidized contacts (see bulb section following) and coat its contacts with dielectric grease. You can clean the wire harness connections with a cotton swab and some white vinegar, rinse with rubbing alcohol on a swab, but be sure the connector is dry (use a hair dryer) before doing the next step. Then, put a small amount of dielectric grease in the connector and work it around with a toothpick. Then, slide the new bulb in and out of the connector a few times to be sure the harness contacts are “clean”. Then, repack the end of the bulb with a small amount of dielectric grease and insert the bulb. Wipe off any excess grease that squeezed out. The bulb and receptacle can now be reinserted into the headlamp assembly.

(4) THERE IS A DIFFERENCE IN BULBS WHEN YOU GO TO BUY A REPLACEMENT. There are “standard”, “long life” and “long life Krypton Gas” versions, and there are color differences between manufacturers. The standard and long life versions are rated from 400 hours up to about 800 hours of life at 12.8 volts. The “long life” Sylvania “optional bulb” number is rated at up to 4,000 hours at 12.8 volts. The Sylvania is also the exact same color as the OEM bulb. Some of the others I looked at were lighter in tint (EiKA, found at O’Reilly’s). The standard replacement bulb is a “3457NA/3357NA”. The standard “Long Life” versions are 3457NALL/3357NALL, and the “optional” Sylvania version is a “4157NALL/3157NA LL”. There is a thread on this bulb situation at the Saturnalia Forum site, and specs on the Sylvania site. It appears, from its design, the original bulbs were Wagner.

(5) The technical information on the Sylvania long life bulbs is readily available. Wagner did not respond to my inquiry about their long life bulbs, even after three tries.

I assume the same oxidation issue exists with the bulb in the right headlight assembly. It was interesting for me to note when replacing my GM bulb assemblies, the originals all came from the factory with dielectric grease protecting the connections.

My concern is the oxidation, whatever its cause, may damage the receptacle for the bulb assembly, so preventive maintenance on these potentially expensive units might be in order for all of our cars. Worst case could be a galvanic reaction between the OEM bulb contacts and the wire harness contacts. All it should take to mitigate the problem is the addition of the dielectric grease and a couple of the longer-lasting bulbs from Sylvania…at least one would hope.

I am going to take a look at the issue of replacing the passenger side headlight assembly right turn signal bulb later in the week as long as everything is apart. It may be a bigger pain (i.e., requiring wheel and fender liner removal, plus additional parts removal) to access the bulb receptacle. I’ll add my observations to this post as I proceed.

UPDATE: The passenger side replacement will require removal of the fender liner, as near as I can tell. If anyone else has done the job on the passenger side, please describe for the benefit of all.

On another note, Shadowman has indicated there is not a replacement headlamp bulb available for the headlight assembly, and when the bulb goes the whole assembly has to be replaced. Very expensive. There may be a way to disassemble and rebuild these units, including being able to simply replace the clear cover (if they can be made or are available), and anyone having a bad/broken one who is willing to send it to me and let me play with it, please PM me and I’ll send you a mailing address. Here are links to a similar process with a Pontiac Solstice unit. The key for us is how the clear cover is removed, and if that would allow simple replacement of the HID bulb or the cover, if available.

Part 1: http://www.youtube.com/watch?v=S1umAEkQV20
Part 2: http://www.youtube.com/watch?v=Nq2FImcV0VI

Any other thoughts on servicing these assemblies, please comment. Thanks!
 

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bonehead

GT Owner
Mark II Lifetime
Aug 18, 2012
2,777
Houston, TX
(4) THERE IS A DIFFERENCE IN BULBS WHEN YOU GO TO BUY A REPLACEMENT. There are “standard”, “long life” and “long life Krypton Gas” versions, and there are color differences between manufacturers. The standard and long life versions are rated from 400 hours up to about 800 hours of life at 12.8 volts. The “long life” Sylvania “optional bulb” number is rated at up to 4,000 hours at 12.8 volts. The Sylvania is also the exact same color as the OEM bulb. Some of the others I looked at were lighter in tint (EiKA, found at O’Reilly’s). The standard replacement bulb is a “3457NA/3357NA”. The standard “Long Life” versions are 3457NALL/3357NALL, and the “optional” Sylvania version is a “4157NALL/3157NA LL”. There is a thread on this bulb situation at the Saturnalia Forum site, and specs on the Sylvania site. It appears, from its design, the original bulbs were Wagner.
Sorry for the second bump of this thread. But the OP's post is a bit unclear as to which bulb is the correct replacement. Is it the 'long life', the 'optional', or do any of the listed Sylvania bulbs work/match OEM?
 

FENZO

GT Owner
Mark II Lifetime
Jul 7, 2008
1,516
Lafayette, CO
THANK YOU richardhead, Shadowman, and nota4re. My driver's side front blinker went out last week. I was dreading looking into replacement as I was expecting at least to have to remove the fender liner.
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
3,791
FENZO, I'd bet money that if you turn on the turn signal and then get out and slap the headlight a few times with an open hand, it will start working again. Kind of a pointless exercise, I guess, because one way or another you'll need to remove and clean or replace the bulb. Oxidation is the culprit, I'm sure.
 

FENZO

GT Owner
Mark II Lifetime
Jul 7, 2008
1,516
Lafayette, CO
That's a good tip, even if temporary... thanks! That will hopefully buy me some time so I can tear into them properly when driving season is over.
 

MAD IN NC

Proud Owner/ BOD blah bla
Mark IV Lifetime
Feb 14, 2006
4,194
North Carolina
my passenger went out - replaced. Same time attacked drivers side as the "coloring of the bulbs differed to what was said earlier.

Once you figure out the fender liner removal - a quick bump and twist, then the bulbs are easy to get to...

The HID bugs me though....
 

RALPHIE

GT Owner
Mar 1, 2007
7,279
I've found that one of the easiest ways to replace any of the bulbs (backup lamp, fog lamp, or turn signal lamp) is to take the car to Rich and Denis (GT Guy), Bill Knobloch (Shadowman@Discovery Automotive) or Kendall (Cooltech LLC). Not only is the work performed flawlessly and professionally, but I get to enjoy the ride to their facilities in one of the most beautiful cars ever conceived.

My 1st choice is usually GT Guy,, as they are the farthest away at about 2,200 miles, which can be traversed in quite a variety of beautiful roads. :wink :cheers
 
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analogdesigner

GT Owner
Mark IV Lifetime
Nov 15, 2005
935
San Clemente, CA USA
Lamp lead almost completely eroded away!

I was attempting to repair the driver's side lamp since it hasn't worked in years. After repairing the badly oxidized leads, I decided to check the passenger side. Even though that side worked, one of the lamp leads had almost completely eroded away! I decided to replace both bulbs with Sylvania units. They had different lead material so hopefully they'll hold up better. Jay

Here is what I saw:

Ford GT front turn signal lamp.jpg
 

fjpikul

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Jan 4, 2006
10,403
Belleville, IL
You have to reach up. The washer tank has a bolt holding it you can see and get at with a wrench. Just take out the bolt, move the tank out of your way, and you have access to the back of the headlight assembly. A lot of this is done by feel. Lying on your back on the floor will make it more difficult to to extend your arm up the back of the headlight assembly. Sorry, can't do any better than that. I know this becasue we replaced my drivers side headlight under warranty, and when we had it all assembled, we realized the turn signal bulb was bad. Since the headlight was already aligned, and we didn't want to yank the liner again, we did as I described. Look in the technical shop manual for pictures.
 

timcantwell

Le Mans 2010 Sponsor * Moderator
Mark IV Lifetime
Le Mans 2010 Supporter
Jan 22, 2006
2,620
N.E. OH & Naples, FL
Thanks for sharing the detailed info. That's the most comprehensive overview of any light bulb change I've ever seen.
 

FENZO

GT Owner
Mark II Lifetime
Jul 7, 2008
1,516
Lafayette, CO
FENZO, I'd bet money that if you turn on the turn signal and then get out and slap the headlight a few times with an open hand, it will start working again. Kind of a pointless exercise, I guess, because one way or another you'll need to remove and clean or replace the bulb. Oxidation is the culprit, I'm sure.
The slap worked. Not sure if that is funny or sad.
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
3,791
My 1st choice is usually GT Guy,, as they are the farthest away at about 2,200 miles, which can be traversed in quite a variety of beautiful roads.
I LOVE this one!!! In a GT, farthest is best. So cool!
 
Many thanks for the explanation! That's VERY helpful.
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
3,791
The slap worked. Not sure if that is funny or sad.
Only scarey part is if it got you aroused.