Topic: Hood turn signal left not working 67

[Ralf]

Hi,
Out of a sudden my left hood turn signal is not working.

Right side works fine as well as the "normal" turn signals front /rear left and right.

Bulb is ok also.

Any idea what it could be?

Thx Ralf

[67gtasanjose]

Wiring likes to break inside conduit down where the hood meets up to the cowl. Another possibility is in the connector below the master cylinder or below hood hinge area.

[Ralf]

I checked the connection. Nothing loosened. And I even grinded (sandpaper) some areas to make sure having 100% connection (earth).
No success.

Seems to be I need to change complete wiring starting from bulb cylinder down to connector plug in (2 pins)?

[67gtasanjose]

I checked the connection. Nothing loosened. And I even grinded (sandpaper) some areas to make sure having 100% connection (earth).
No success.

Seems to be I need to change complete wiring starting from bulb cylinder down to connector plug in (2 pins)?

Perhaps changing it would get it working again. You likely have the mid-year, early version of the TS hood harness that is not currently reproduced. The later version does fit and function but differs in appearance. Personally, I would try and search out the issue if I still had an original harness with the cloth/tar conduit on it. On my 11/2/66 built San Jose example, I did replace this many years ago (similar issue) with the later version and more recently built my own "early version" by sourcing a damaged original to use as a pattern, an Alloy Metal (current replacement) and some new cloth/tar conduit. I removed the incorrect bulb sockets, cut the wiring down for the correct lengths and re-assembled the correct bulb sockets onto the new wiring. Not perfect, but a very nice attempt in my opinion (given the lack of availability of a correct one).  If my guess is correct, (using your build date), your hood wiring is threaded through two holes in the inner structure and at those holes (in the hood structure) you should have the grommets in the hood. You should also have 3-4 push-in clips holding the wiring to the hood. (later versions used "P"-shaped plastic hoops and bolted to the hood louver mounting studs, yours should not be this way)

[67gta289]

swap bulbs with the one that is working to see I the problem moves or not.  this is an easy bulb check.

check the bulb socket "tulip leaves" (for lack of a technical term) that ground to the bulb assembly housing, make sure they are getting a good connection.

you can take a piece of wire and temporarily by hand touch a known good ground on one end and one of the socket "tulip leaves" to see if it starts working.  If it does you know that the supply side and bulb are good and you have a ground issue.

[67gtasanjose]

If you change the harness, you might wish to read through this thread:

http://www.concoursmustang.com/forum/index.php?topic=13686.msg84791#msg84791

[Ralf]

swap bulbs with the one that is working to see I the problem moves or not.  this is an easy bulb check.

check the bulb socket "tulip leaves" (for lack of a technical term) that ground to the bulb assembly housing, make sure they are getting a good connection.

you can take a piece of wire and temporarily by hand touch a known good ground on one end and one of the socket "tulip leaves" to see if it starts working.  If it does you know that the supply side and bulb are good and you have a ground issue.

I changed the bulb from left to right side. Bulb works. Checked bulb as well on battery with wire on + and bulb on-. Ok, works.
Need to check if voltage on left wiring string is missing....obviously the right side has.

[CharlesTurner]

Another easy test is to turn the turn signals on, then pull the socket and try grounding the tabs to the hood to see if the bulb blinks.

Other than a bad ground, as others have mentioned, possible issues with the wiring.

[Ralf]

Another easy test is to turn the turn signals on, then pull the socket and try grounding the tabs to the hood to see if the bulb blinks.

Other than a bad ground, as others have mentioned, possible issues with the wiring.

I did the test as well. Problem still there.
Will propably buy a cheap Scott D wiring to test it.