TURN SIGNAL NOT WORKING


NorthwoodGT

GT Owner
Jun 12, 2009
1,215
Michigan
I'm stumped on this one. emergency flasher works on both left and right, front and rear so we know it's not a wiring issue.
Left front turn signal and rear left turn signal work fine. Right front and right rear turn signal- NOTHING. had the GEM out a couple times for other issues. a wire pulled out? multi-function switch? all worked fine before. it's not a ground or a battery issue.
suggestions?? thanks
 

fjpikul

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Jan 4, 2006
11,475
Belleville, IL
Bad bulb?
 

nota4re

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Feb 15, 2006
4,176
Bad bulb?

emergency flasher works on both left and right

Maybe a SmartBulb, but not a bad bulb.
 

fjpikul

GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Jan 4, 2006
11,475
Belleville, IL
Isn't there more than one filament in the turn signal bulb up front?
 

NorthwoodGT

GT Owner
Jun 12, 2009
1,215
Michigan
if the emergency flashers work, it's not the bulb
 

PeteK

GT Owner
Mark II Lifetime
Apr 18, 2014
2,267
Kalama, Free part of WA State
Scott, I havne't dug into the wiring diagrams yet, but I'm certain the turn and flasher lights are controlled through the SJB (smart junction box). They have to be, in order for the key fob to activate them when you remotely lock the car--speaking of which, when you lock the car with the fob, do the lights flash?

Then I'd look closely at the turn signal switch. These do wear or fail. Fiddle with it and see if pushing harder or forward or backward whilst engaging the turn signal makes any difference. The turn signal switch is easy to get to. Back when I first bought my car and joined the list, I wrote up a procedure for removing the cowl around the steering wheel. My tilt-wheel lever adjuster had loosened and was not holding the adjustment very well. Anyway, two or three screws hold on the cowl halves, and then you can get to the connectors and turn signal switch. You can try to jumper around the switch and see if the turn signal activates.

Next, I'd get into the wiring diagrams and see if there is a replaceable flasher for the right turn signals. Probably not, because the SJB most likely handles that function too. But the diagrams will give you the current flow and show where to check for continuity or signal and the wire color codes for jumping around the switch.
 

Johntpr

GT Owner
Mark II Lifetime
Jan 18, 2017
235
Rockland County, NY
Maybe some of the diagrams from my thread may help you? See below. My issue wound up being the SJB, but a turn signal switch being bad can also be the culprit. They are cheap enough and easy to change.

http://www.fordgtforum.com/forums/s...ide-Tail-light-Issue-comes-on-dimly-by-itself
 

FBA

GT Owner
Dec 5, 2010
1,663
31.022340° N / 44.846191° W
Turn signal switch; mine failed on the high beam / low beam. I'd bet big it's that.
 

thegtguy

*Supporting Vendor* GT Owner
Apr 20, 2006
545
MI
I'm stumped on this one. emergency flasher works on both left and right, front and rear so we know it's not a wiring issue.
Left front turn signal and rear left turn signal work fine. Right front and right rear turn signal- NOTHING. had the GEM out a couple times for other issues. a wire pulled out? multi-function switch? all worked fine before. it's not a ground or a battery issue.
suggestions?? thanks



Im inbetween a few cars. Bring it down next week. Should be able to figure it out.
 

NorthwoodGT

GT Owner
Jun 12, 2009
1,215
Michigan
thank you all for your offers of help and especially Rich. I haven't been back at it in a couple weeks. 4 funerals in 10 days plus too cold (or I'm lazy) to put the heat on in the shop.
anyways, I found it. as mentioned before, the GEM module or smart junction box at the passenger floor can be a fickeled bitch my friends. I had it out to change something else and I thought I was very gentle with it. however it says casted right in the plastic of the box "scrap if dropped more than 20cm". I swear it never got dropped but maybe it got bumped and took a G load of some kind. replaced the GEM with a new one and presto, everything works.
made no sense to me because the bulb worked fine in the head lamp and the tail lamp worked when putting on the emergency flashers which is the same lighting elements for the turn signals. so I'm back in business and won't have people yelling at me when I make right turns with no signals this coming summer
 

PeteK

GT Owner
Mark II Lifetime
Apr 18, 2014
2,267
Kalama, Free part of WA State
GEM module huh? Wonder why it only affected the right turn signal?
 

CJ428

Farm GT
Mark II Lifetime
Le Mans 2010 Supporter
May 21, 2008
1,473
NJ
I would have thought it was the switch.