C1 C2 Cigarette Lighter Confusion

[Richard M.]

This is driving me craaazy. I bought a nos Casco element for my 59 for the Regionals last Jan. I installed it at the last minute before the 100 mi drive to Kissimmee. Because I never tested it at home, of course you know what happened. Driving along about an hour into the trip, I looked down and said" Oh, Shxxxxxxt, never tested than new lighter element."

Now a few days earlier in preparation for judging, I noticed some oil drips at the rear of the oil gauge(hmmm, just above the lighter). Cleaned them off and went to the next thing on the list.........Fast forward back to driving to Kissimmee.....

Pushed the lighter in to check it out........Kapow!!! A mini explosion, fire, smoke.....Yikes! What the heck happened! I pulled over, smoke cleared from the interior, looked under the dash and my red wire to the lighter was fried. Of course I lost points in the ops check, but got full credit for the nice nos element with it's white ceramic insulator.

So I finally got around to fixing the lighter feed wire, and put a nice fuse holder inline with the lighter. Thinking I had the wrong nos part(right box, wrong part), I ordered a replacement, just tried it but it blew the fuse. My original 59 element is shorter than the nos & the replacement & the 63's. Huh????

Do I have the wrong lighter housing in my 59, which is what caused the short & fire, aggravated by some oil on the housing?

The parts book says
55-62 = 3710581
63-72 = 3794302

Pics L to R are:
my 59( marked 78 CASCO 12V),
the replacement(marked 72 CASCO 12V),
the NOS,
the 63

-NOS 3710581 (marked CASCO 12V) the fire culprit

-Our 63 original(?) (marked PAT PENDING CUNO MERIDEN CONN 12V)

-All 4 showing height differences

[Dennis A.]

Re: C1 C2 Cigarette Lighter Confusion

Richard...
If a replacement Casco restoration part is installed, a U-shapred bi-metallic element at the feed connection was added. This bi-metallic element is designed to "dead-short" the lighter if it gets to hot. (bad news is the C1 and up to '66 corvttes don't have a circuit fuse. Remove the nut, pitch the U-element, and re-install the nut to eliminate this potentail problem...
Hope this helps....

[Jack H.]

Re: C1 C2 Cigarette Lighter Confusion

1955, 12V, Corvette used a 1-year only Casco L48C lighter element. It's identical to the L144C element used on 56-62 cars but LACKs the external sliding ash guard feature. Mid-year Corvettes used a Casco L160C lighter element which is similar to the L144C but slightly shorter in length plus they're embossed with the distinctive '63 Casco 12V' legend versus the simpler 'Casco 12V' legend.

Mating sockets for the lighter also changed during this era. The early C1 cars had the socket mounted in a hole in the fiberglass dash. From '58-62, the socket mounted in a recessed well in the instrument cluster. The '63-67 socket is similar but simply shorter in overall depth to match the shorter lighter element...

The early C1 sockets had a wider upper flange to spread their insertion force across the dash interface while later C1 sockets had a thin flange allowing them to slip inside the instrument cluster's lighter well. All three sockets (early C1, late C1, and C2) had three discrete holding prongs to keep the element in contact with the socket's power electrode. Later era service replacement sockets used two prongs and MANY of these have the bi-metal fuse 'feature' that's been discussed.

BUT, it's generally NOT the bi-metal safety fuse that causes the problem you mention (power lead wire going up in smoke). That only happens with a fused, service replacement socket when there's a bona fide short circuit condition that flows too much current and triggers the bi-metal to change dimension and short out...

What typically causes these wiring melt-down episodes is 'Bubba'.... He removed the lighter socket and decided to 'clean' it up by disassembling it, removing the interior electrode & ceramic insulator. Then, he forgot/failed to record the component assembly sequence and put the individual pieces back together OUT of their original installation sequence!

Now, the socket's electrical insulation configuration is defective and one of two things happen: (1) the socket is a permanent dead short to ground causing the wiring to burn as soon as it's connected, (2) the socket becomes a dead short to ground as soon as the lighter element contacts the power electrode.

Bottom line, beware of Bubba and practice the due diligence to verify the continuity path of any replacement power socket before you install it!

[Richard M.]

Re: C1 C2 Cigarette Lighter Confusion

Found it......Dennis, the socket doesn't have that u-shaped link. Good info though. Jack, great info, thanks for the details. Never saw the L14x part #'s on any elements. Too bad they didn't add them.

I removed the socket from the cluster to see what's going on here. So what caused the short? Yup, Bubba was there, 22 years ago! It appears that Bubba got the 55 style element, and it wouldn't reach the 2 socket contacts, so he BENT them in and up! When I tried the correct longer element, it shorted the outer housing to the 2 contacts. Bang!

I removed the original socket from my 62 project car and compared the two. So on the 59 socket, I just bent the 2 contacts back down and the nos & replacement elements fit correctly with no short circuit. Pics below. 1st pic is the 59 with the wrong short element after bending contacts to where they should be, won't reach. 2nd pic is the 59 socket with nos element, ok. Last 2 pics....Lefts are the 59, rights are the 62. Note the 59 is stamped"1971", the 62 has no date. Also note diffs in the metal contact widths at the base. It appears the 62 socket is original.

Thanks,
Rich

[Richard M.]

Re: C1 C2 Cigarette Lighter Confusion

Oh....one more thing. The 59 cluster is recessed for the socket, yes. The 62 has a bezel around it to raise it further out towards the driver. Sockets appear the same, but the inner screw-on housing is shorter.

[Jack H.]

Re: C1 C2 Cigarette Lighter Confusion

Yep, Bubba HAS been in the car!

First the socket is a 2-prong replacement AND the dash harness has been cut/modified to make it work with the screw-on spade lug terminal that's been installed on the socket.

Factory originals had 3-prongs to grab/hold the lighter element (see pix) and they had a threaded brass 'nipple' installed on the power stud so the dash harness' barrel connector would slip/snap in place.

Many remove a corroded original cig socket and don't realize the brass power stud adaptor simply un-screws and can be transferred to the replacement socket. Sooooo, they PITCH the original socket, install an L-bracket onto the power stud and CHOP the wiring harness, discard the factory original connector and crimp on a sliding spade lug in its place....

[Richard M.]

Re: C1 C2 Cigarette Lighter Confusion

Right you are Jack. I just realized that our 63 has the 3 prong socket, and a used one I have for the 63 has 3 prongs, and the brass stud for the connector. (1st 3pics)

I think the 63 up used the stud as you say. My 59 and 62 both have the female spade terminal & plastic connector housing on the harness which I believe are very original. I also have a nos main harness I got for the 62 and it has the female spade connector too.(pic 4)

Maybe the 63 up used the brass stud? Our 63 harness has the round connector to mate to it. One other thing I noticed is the element with the used 63 socket I have is short like the original 59 element I had, but it has the sliding ash guard(pic2) as you mentioned. Also says 63 CASCO, with white ceramic piece(pic3), but metal threaded part(pic2), not black bakelite like your original.

Either way, this excercise taught me much. Thanks for your help!

Rich

[Dennis A.]

Re: C1 C2 Cigarette Lighter Confusion

Jack...
Learning something new every day is a good thing....T.U.
Dennis

[Richard M.]

Re: C1 C2 Cigarette Lighter Confusion

Dennis, I finally found the C2 lighter socket I bought a while ago. Here's a pic of that U-shaped thingy you were talking about....Rich

[Jack H.]

Re: C1 C2 Cigarette Lighter Confusion

Yes, the 'U-thingy' is the bi-metal 'safety' circuit overload feature. When it gets hot, it changes shape and short circuits the center electrode post to the outer brass housing (which is electrical ground). This is potentially UNSAFE for early cars that didn't have an upstream fuse on their cig lighter wiring branch circuit!

The 'fix' is to hold the socket and unscrew the center brass terminal adaptor from the electrode stud. Below the adaptor is a hex nut/washer holding the bi-metal safety breaker in place.

Remove the nut/washer, lift off and discard the bi-metal and reinstall the nut/washer and brass adaptor nipple. DO NOT remove components below the bi-metal! That's where the stacking order of assy becomes important for the socket to retain proper electrical isolation.

Also, not the service replacement socket has the current day 2-prong vs. factory original 3-prong design. My hunch is the change came from the proliferation of 'foreign' peripherals being plugged into the socket to power things like radar detectors, computers, Etc...

If the power tap plug-in isn't 'correctly' sized for the socket's intended geometry, it can distort the 'power prongs' and cause lighter elements not to stay connected and/or launch too early/too late in their heating cycle. My bet is Casco intentionally went from three to two prongs to lessen the impact of poorly designed aux power taps....