Cigarette Lighter - 1954 - Grounding Help

[Russ U.]

The cigarette lighter on my 54 does not work. It is clean and should work.

I have the correct red wire running from the lighter to the ammeter. The lighter case only contacts the fiberglass dash. So I thought the lighter was supposed to ground via a black wire to the metal dash panel. When I grounded the lighter to the metal dash frame for a few seconds, the lighter got hot all right. Smoke everywhere. I completely fried the ground wire from the lighter to the metal dash.

Everything else on the dash works - including the radio and the heater.

What am I doing wrong?

Does the lighter ground to the metal dash? If so, why did I fry the ground wire? I am missing a ground somewhere else?

Thanks

Russ

[Stephen L.]

Re: Cigarette Lighter - 1954 - Grounding Help

The gauge of wire used is the question. It must be equal or greater than the supply wire. A cigarette lighter draws a lot of current. #14 would be a minimum in my estimation...

[Jack H.]

Plus...

current day Casco sockets come with a 'safety feature' that can be 'death' to older cars... They have a rectangular bi-metal circuit breaker that's mounted on the rear power stud of the socket. It's there as a safety feature.

If the cig socket should over heat for any reason, the bi-metal strip changes postion and effects an electrical short circuit between the socket's power stud and the socket's outer shell which is electrical ground. This is intended to cause the up-stream fuse for the cig lighter to pop and remove power from the cig lighter before electrical damage occurs...

Unfortunately, the very early cars did NOT have the cig lighter on a fused circuit, so should the 'safety' feature of the lighter socket engage (for any reason), it creates rather than prevents an electrical fire!!!

Those with early Corvettes where the cig lighter is powered on an un-fused branch circuit need to visually inspect their cig sockets for the presense of this circuit breaker. You simply look down the rear power stud and if you see a rectangular metal plate on the power stud that comes 'close' to touching the outer threaded barrel of the socket, remove it.

[Robert S.]

Re: Cigarette Lighter - 1954 - Grounding Help

Russ,

The case for the 54 lighter should have a metal tab off the back side for the ground wire to attach which then attachs to the metal dash frame.

Did the lighter pop out or did the ground wire start smoking right way? You may have used too small diameter wire or if the lighter is not popping out it may have just over-loaded the ground wires capacity.

Bob

[Roy B.]

Re: Cigarette Lighter - 1954 - Grounding Help

Keeping my NOS parts in pic's this may help you understand the ground "black" wire is the same size as the hot wire. The grounding is the dash support plate stud.Hope this helps!!This is for 53 to 55 only!!

[Russ U.]

Another Meltdown - Please Help!

I rewired the cigarette lighter (red wire to ammeter, black wire to a dash metal frame support screw, etc). And I checked the main dash ground into the metal dash panel (grounded to a screw on the hood pull support). I also did NOT insert the cigarette lighter element. Thus, I think everything was properly wired and I had just the cigarette lighter shell and guts.

Another meltdown occurred as soon as I connected the battery. Smoke everywhere within a couple of seconds. (I am getting quicker about unscrewing the battery shutoff system, however).

Attached is a picture of my entire cigarette lighter system. I don't see any of the later model bits in here, so I don't think I have that problem. What the heck is wrong????

I had to bubba a way to attach the ground wire to the lighter shell using a screw and a nut. The nut is touching the shell - but I don't see how that could be the problem.

All of my other dash instruments still work fine - clock, radio, etc.

Thanks for the help so far, and please let me know if you have more ideas.

Russ

[Roy B.]

Re: Another Meltdown - Please Help!

OK this time before you install it in that old Vett ,use a battery changer to check that it don't burn the wires.
Sounds like the housing ( which is the ground) is shorting out against the inside HOT wire area (the little three prong thingee) .pic. Here shows the 6V upper left heavy coil and the 12V thin coil.Bottom the 53 to 55 ONLY unit design then the later 12V 56 design.. 53 to 55 'U" shape cuts hold it in the housing till it gets hot.

[Jack H.]

Easy answer...

Your exploded view lacks the electrode's insulating washer and the socket's threaded end cap (what the socket retainer screws onto to hold the socket against the dash). Without the electrode insulating washer holding the electrode stud DEAD NUTS in the center of the socket well and prevent electrical contact, you can wind up with a dead short from power to ground!

In the future, when you take a lighter socket apart and re-assemble it, don't 'test' it with full power in the car! Use a multi-meter, set on the ohm scale, to verify there is NO continuity between the electrode stud and the socket's outer well before you install and connect power...

[Russ U.]

Thanks Guys - It Works!!!!

I had multiple shorts going on within the cigarette lighter. After reading the last follow-up posts by Jack and Roy, I could tell exactly what was going wrong. I "borrowed" a few parts from my 59 Corvette lighter (which I keep disconnected), and then bench tested my 54 lighter. Works great.

I know understand why the prior owner had the lighter completely disconnected.

Thanks to all who helped me out.

Russ