Turn signal malfunction question '55 Thunderbird


http://forums.y-blocksforever.com/Topic160821.aspx
Print Topic | Close Window

By Joe-JDC - 3 Years Ago
I am getting my '55 Thunderbird ready for the yearly state safety inspection and found the left rear turn signal not working.  The lights work, brake lights work, tag lights work, right turn signal works front and rear, but left turn signal front light comes on and stays on--no blinking, and left rear turn signal--nothing.  I have pulled the bulb and changed it, traced wires for any frayed or broken, none found.  Pulled the steering wheel and removed the turn signal switch to check it for proper actuation, seems to be ok. Flasher?  Ideas?   Joe-JDC
By MoonShadow - 3 Years Ago
Check the grounds on the bulbs.
By Joe-JDC - 3 Years Ago
The brake light and tail light work fine. Just not the rear turn signal portion.  Joe-JDC
By 55blacktie - 3 Years Ago
Joe, you might find an answer here:rosecitythunderbirds.org
By Ted - 3 Years Ago
This is from the link posted above.  The following looks like a likely area to start with.

Problem #3 (all pictures) Probably the most difficult problem to diagnose and repair is when the turn signal turns off but does not return to center. When this happens the brake light on the side where the turn was last signaled will stop working. Anyone following you will only see one brake light working. To fix the problem you will need to look at several things. First check the pawl (part #13309) for wear. Rounded corners on the pawl will allow them to slip off the steering wheel cam ring and cause the turn signal plate to hang up in the top of the detent. If the corners are rounded, replace the pawl. Next check the steering wheel cam ring (part #13318) to make sure there is not a groove forming where the pawl contacts the cam ring. If you can feel a groove, replace (or turn over) the cam ring. To replace these parts use the process described for problem #1. When you replace the pawl check the turn signal plate to make sure the roller has a good downward pressure on the detent and bend the plate if necessary to increase the pressure.

            One additional thing to check is the height and position of the turn signal plate assembly under the conical spring. This area of the plate assembly must be flat and evenly contact the top of the turn signal switch. If it is not sitting flat manually bend the plate until it does. Check to make sure that the two button-head screws holding the turn signal switch in position are tight. Recently I ran across a case where the wrong screw had been used to retain the turn signal switch. The screw was too long and it had the wrong head. A lock washer had been added to secure the switch causing the bolt head to protrude above the top surface of the switch. This was holding the turn signal plate assembly off of the switch and prevented it from properly contacting the steering wheel cam assembly and turn signal detent. Check these screw when working on your signals to be sure they are both the correct button-head screws.

            (Editors note: I’ve observed this exact same problem being caused by white grease being applied to the mechanism. It has a tendency to dry out and become very stiff. A good cleaning was all that was necessary.)
            This may seem like a lot of detail but it is well worth the time spent to get your turn signals working properly. It sounds harder than it is. These repairs are quick and easy and the parts are not expensive.
By Joe-JDC - 3 Years Ago
Turn signal lever cancels fine, left or right, I removed all that and checked for bent or broken parts, actuated the switch with my hand with key on, same results: no left rear light on for turn signal-only.  Brake and tail light work.  Joe-JDC
By Joe-JDC - 3 Years Ago
Have you ever checked things, modified a couple, and moved things around, not really finding a fix, pull something to look at it, put it back, and "presto", it works?  I bought a HD Flasher, removed the original, checked a couple of taped up wires, but decided to check the turn signals while I had my head under the dash before getting out.(It is not easy laying on your back, upside down in a Thunderbird's floorboard when you are 75 years old. LOL.)  I put the original flasher back in its holder, and those turn signals worked like a champ.  It is working, but I do not know what fixed the problem.  Maybe a wire not fully engaged, or I made a better ground somewhere.  Anyway, thanks for the advice, and fingers crossed.  Joe-JDC
By paul2748 - 3 Years Ago
Check the wires at the steering column - the junction block..  Maybe they came loose or are in need of repair.  From what you are saying, the front signals work??
By 312YBlock - 3 Years Ago
The turn signal wires go through junction connector blocks on the front of the fender aprons on both sides. I had the same problem. Turn on the blinker then jiggle the wires in the JB’s. Corrosion on the connectors/wire tips are a likely cause. I replaced both, problem solved.
By Joe-JDC - 3 Years Ago
Turn signals work.  Inspection completed this morning.  Got my license plate renewal for another year.  Car drove great, shifts easy with the 5 speed.  I changed the master cylinder, bled all the brakes, adjusted all the brakes, and it drives like a different car.  This thing scoots with the 345 Y.  Ready for a longer cruise, now.  Joe-JDC
By MoonShadow - 3 Years Ago
What was the problem? 
By FORD DEARBORN - 3 Years Ago
Great to hear about it.  A T5 really modernizes the driving dynamics of these classic vehicles, especially behind a Y-block.  Have fun Joe.................
By Joe-JDC - 3 Years Ago
MoonShadow (4/21/2022)
What was the problem? 
  Read post #7 again.  I don't have a clear-cut answer, but probably the original flasher wires had some corrosion, and when I moved them around, they made good contact again.  I will go with that for now as the answer.  Joe-JDC

By MoonShadow - 3 Years Ago
I've chased them before. I bought one of those color wiring diagrams for my 56 so I could figure out the wires to the block under the dash. Replaced the TS switch but wasn't carful enough reconnecting the wires. Finally all good.  I had to pull the connectors on the fender in and out several times to sort out those ancient connections. Chuck