Turn signals: Driver side works, passenger side doesn't

[RC92234]

Tried the turn signals today.  Driver's side blinks at what seems to me a very slow speed, but it does blink on the dash indicator and both driver's side front and rear fixtures. 

Passenger side does not -- at all.  Dash indicator lights up solid, front lamp seems to be out, and of the two bulbs in the passenger side rear lamp, outboard is *far* brighter than inboard.

It's a very, very old recollection but it seems I recall when one lamp was out in a blinking circuit, the circuit blinked faster.  That is definitely not what's happening here.  After I replace the front bulb and make sure the rear bulbs are both the same wattage, if it's still not blinking, where to look next?

 

[c9zx]

Assuming the bulbs checked, look for bad grounds and or corroded/damaged sockets. I use a small burnishing tool and a product called Deoxit D5 and G5 to clean sockets. Let us know what you find. Chuck

 

[71fast]

Do the stop lights and tail lights work ok?  The stop light is a signal light too.

 

[Don C]

+1 on grounds and corrosion. The bad grounds or corrosion creates a higher resistance in the circuit, which reduces the load through the electro-mechanical flasher enough so that it won't flash.

 

[RC92234]

Going through and checking connections is a good exercise, and found the issue:  the spare tire had somehow moved just enough to bump into the passenger rear tail light and push one of the connectors to nearly-not-touching.  Surprised that would make the front lamp not work, but once I got the back lamp connections secured, all the lamps worked fine.

Now about that spare tire:  I think it's original.  Firestone F78-14 Belted.  Never been on the ground.  Of course it's dried out, cracked and pretty much useless now, but hey -- "one from the vaults".

 

[c9zx]

Glad you fixed the problem. Chuck

 

[Carolina_Mountain_Mustangs]

I suggest anytime you are going through cleaning and checking connections you get a tube of electrical connection grease. Anyone that has owned a boat or camper can tell you it works. Once you clean the connection coat with the grease and will not corrode. Permatex was last I got at my local Advance Auto store.

 

[bdennis]

Just to add to this topic and it is great that the initial problem is fixed..

The indicators on my 72 Mach 1 flashed vey slowly but all worked ok. Before I got around to checking the ground, I ordered a replacement flasher can.

I quoted my local parts supplier (In Australia) the number in the Scott Drake book (C5AZ-13350-B). This is listed as being for a 65-70.

While the one that was delivered does not have the plastic case and small lug/clip on the end to clip in under the dash above the glove box, the pins do line up for my 72. 

After installing the new flasher, the indicators work perfectly...

In terms of mounting the flasher can, I cabled tied it to the metal bracket that the old one was plugged into so it does not rattle against the metal when driving down the road.