Turn Signal Switch Advice Needed

[Rumblefish]

I'm working on a 1971 Mustang (Mach 1 tribute). I replaced the turn signal switch because they weren't working. It was a hassle because the switch I bought didn't have the factory plug in, so I had to solder the 10 wires with shrink wrap but I got it done, installed it and the turn signals worked great. Next, I noticed the interior turn signal lights on the dash/gauge weren't working. So I unplugged my circuit board behind gauge pod and began testing the pins on the plug in with my ignition on and turn signal on to see if I was getting juice to the plug in. It may have lit up for a half second, then nothing. Now my turn signals won't work.  Did I damage the new turn signal switch? Do you think I need another one (they're over $100 plus shipping).  Any ideas?

 

[Don C]

I would start by checking the fuses.

 

[midlife]

Only check fuses if every turn signal lamp doesn't work. If only the dash isn't working, then something is amiss with the wiring to the dash cluster, the circuit card, or the lamps.

 

[Rumblefish]

Only check fuses if every turn signal lamp doesn't work.  If only the dash isn't working, then something is amiss with the wiring to the dash cluster, the circuit card, or the lamps.

I don't have any turn signals. Not working in the front, the back or inside dash indicators. Brake lights work. Emergency flashers work.

 

[midlife]

Check the upper most left fuse to see if it is blown. Does your factory radio work? Backup lights work? If either of them do, it isn't the fuse.

 

[Rumblefish]

Check the upper most left fuse to see if it is blown.  Does your factory radio work?  Backup lights work?  If either of them do, it isn't the fuse.

TY. Will check those tomorrow. I appreciate your help.

 

[Rumblefish]

I turned the key on and put car in reverse and the back up lights came on. Then I activated the turn signal lever and heard the turn signal flasher behind the glove box click once, then it went dead. Now I have no back up lights or brake lights. I checked all the fuses with the key on, the turn signal/back up fuse is hot on both sides. I'm making a mess outta this. I'm kinda stumped right now.

New Development: I was checking the fuses again with my test light and I put the probe on the turn signal fuse (maybe kinda pushed on it) and the turn signals started working.

I think I'm on to something. Will update.

 

[delawarebill]

getting corrosion on the fuse terminals and fuse itself may not happen a lot but it does happen. if probing the fuse made a better connection then i'd pull the + off the battery and pull ea fuse and clean the ends. if u had an issue with one the u may have #2 coming soon.

 

[Carolina_Mountain_Mustangs]

I know it is too late now but you did not have to cut and splice the wires to get the plug on the turn signal harness. The plug actually comes apart and you just put the new harness back in and snap back together. I think the inside part of the plug that I believe was red pops out and releases all the pins on the wires. I did my 73. You just need to make you a sketch of where each wire goes to keep it straight. My car was tilt column also which is different turn signal switch also.

Mine was working then the L.H. stopped blinking got to check ground and bulb.

 

[Rumblefish]

I got it. It was a corroded 20A fuse that wasn't blown, just making bad contact. I removed the old fuse, cleaned the terminals and applied di electric grease and new fuse and turn signals, brake lights, back ups working good. TY to everyone.

 

[Don C]

Pretty common problem with older cars. They can get corroded on the inside, too, look fine but not work right. Sometimes heating the end with a soldering iron enough to melt the solder in the end caps will fix them.

 

[Mister 4x4]

I had a similar issue with the horn when I went to get the car inspected.  Got it home, the horn still didn't work, so I took everything apart and tested.  Of course, the last thing I tested was the fuse.  The test light lit up on both sides when I checked it, but I pulled the fuse anyway and found a good fuse, with a little bit of corrosion on the ends where it rested in the panel.  So, cleaned up the clips and installed a new fuse (I have a big bag of old glass fuses) and all was good again.  I cleaned up the 'old' fuse and tossed it back in the bag.