1966 Rear Lights

[Vito D.]

Good morning,

I seem to be having a problem with my drivers side rear light. Only the dim filament works for the brakes, turn signal and driving lights. The passenger side works properly; i.e. bright brake lights and turn signal, dim running lights. Based on researching previous posts, I've removed the rear valance to inspect the grounding wires, which appear to be tightly secured. I've also swapped the bulbs since the passenger side is fine, and have confirmed that it's not as simple as a defective bulb.

Has anyone had a similar situation, any thoughts on what my next step should be?

[Mark W.]

Re: 1966 Rear Lights

You've probably already done the basic checks, but if not, check all the wiring at the connectors and sockets and clean the connectors/sockets.

[Tom H.]

Re: 1966 Rear Lights

I'd vote bad socket.

[Louis T.]

Re: 1966 Rear Lights

Hi Vito,

I agree with Mark and Tom, but it would help if you provided us with some additional data. Did this malfunction happen suddenly or did it follow any repairs or maintenance, e.g., the removal, repair, or replacement of your taillight housing, connector/harness, or lamp? Also, are you sure only one filament (the dim parking light filament) is lighting, or are you surmising that because the brake and signal lights on the driver side appear as dim as the parking lights on the passenger side? If the latter, are you certain that all three functions (parking, brake, and signal) on the driver side appear similarly dim?





Good luck!

Louis

[Vito D.]

Re: 1966 Rear Lights

Thanks for all the advice guys. It appears that it's time for me to purchase a multimeter.

This occurrence did not follow any repairs or maint. I've had the car for 2 yrs, and it's my weekend driver. I really don't know if it just happened, or if it's been that way for a while. I am confidant that only the dim filament is lighting because I removed the lens to confirm. I get the same result when putting the "good" bulb on the drivers side.

I'll attempt to clean the connectors better, and then follow the general diagnosis. In reviewing other posts, it seems that there are a multitude of products to clean the connectors. Does anyone have a preference?

Thanks for taking the time to respond. I appreciate it.

[Joe R.]

Re: 1966 Rear Lights

Vito,

A very fine sandpaper like 1000 or 1500 will clean the contacts. Then use what is called a dielectric silicone grease in the socket. It keeps the moisture out and does not conduct electricity to prevent arcing. This can be found in electrical supply houses and maybe Radioshack. A good brand is Dow Corning 4 for this purpose.

Somewhere, sometime you will find a bad contact. Probably in the socket at the lamp itself or as someone suggested a ground. All these connections are subject to water and dirt. Both enemies of the flow of electrical current.

JR

[Doug F.]

Re: 1966 Rear Lights

i'm with louis, ground issue,i've found that you loose ground where the socket is riveted to the housing, i fix this by soldering a wire from they out side of the socket crimping an end to it and install it under the original ground wire, that or just install a new light, my dad taught me years ago that 98 % of all electrical issues on a vet are ground related and i've found that to be pretty close, cary

[Bill C.]

Re: 1966 Rear Lights

One of the biggest faults I find with these lights is the mechanical joint between the inner socket mounting plate and the outer chrome die cast housing. It is also the only electrical conduit for the ground to reach the bulb socket.The mounting stud where the ground wire attaches is part of the chrome die cast housing, the inner socket mounting plate is poorly staked to the housing via 3 stand off's on the housing thru the mounting plate. Then the socket is pressed into the plate.
Over time, these mechanical joints loosen and after a few cycles of water exposure, etc. the electrical connection between them will become marginal and fail. Check conductivity from the bulb socket out to the mounting stud, thats probably where you will find your problem.
Solution? Buy a new quality lamp, NOT the cheap imports. I have had those literaly fall apart when trying to install bulb/wiring harness connector

[Vito D.]

Re: 1966 Rear Lights

Thanks everyone, it was in fact the GROUND. I placed a jumper from the "backup light" ground over to the outside of the socket and that resolved the problem.

Now that I need a permanent fix, I presume that I'll remove the socket completely and determine if a repair can be made. If not, then I'll try the soldering technique that you mentioned Doug.

I'm sure this was the 1st of many electrical learning experiences to come.

Regards.