Light wiring/LED help?!

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stackattack

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So my 65 Barracuda I am finding has some odd lighting going on. It looks like the previous owner opted instead of keeping the reverse lamps (which it has) to replace the lens with a red one and use both lamps for extra lighting on the rear. I guess this is because the lights are small and wanted to be seen better. Issue though is that by wiring them together both lamps don't get full 12v and are dimmer when paired up -- which to me negates the original intent doesn't it?

Anyway --- moving forward I would like to possibly get LED bulbs for them for now and I won't address the reverse lamps til later (maybe some mustang-style bumper reverse lamps??). But for now, anybody know a reliable lower voltage LED 1157 type bulb (like maybe rated for 9-12v) or possibly a 5v LED that maybe is a better fit and will make them brighter? They are currently wired for tail light/brake/and signal to both bulbs.

1965barracudataillight.jpg
 
I think you may have a power supply problem to the rear. In '66 they used two brake lights on each side and they were plenty bright enough with stock bulbs.
 
I think you may have a power supply problem to the rear. In '66 they used two brake lights on each side and they were plenty bright enough with stock bulbs.
yeah but in 66 they probably have seperate wiring for those tail lights? Or no? I only have 2 pairs going back to each side -- supposed to be one pair for tail/brake and other for reverse. My reverse wires are doing nothing (hanging) and the other pair is run to both lights on each side....
 
Nope, just one 18 gauge black wire runs all 4 taillight bulbs and the license plate light.
 
hmmm... so what is the voltage that I *should* be reading at the tail lamp wiring? gonna dig in..maybe something bigger wrong here...
 
LED bulbs WILL BE brighter. They draw less current, so even though factory wiring "is a bit light" if connectors/ etc are all OK they will be fine. But there is a lot of Chinese crap out there. Up to you to research and come up with bulbs that are good quality.

But maybe I misunderstood? How are the former reverse lights wired, or what is it that you are using them for?

Are they still single contact sockets as original? Are they going to be used for stop/ turn, or tail or both? There's a whole bunch of ways they might have been re-wired, and the replacement bulbs/ LEDs used will have to match.

Original.......single contact, wired together for reverse

Same as above would work for additional tail only Don't remember the lamp number for low wattage tail, maybe 1141

Separated wires to each side single contact could be used for additional stop/ turn with 1156 or equivalent lamps

Converted to dual contact tail/ stop/ turn you would use 1034/ 1157 or equivalent
 
Should be 12V. If it's a current problem, it may be low amperage from a bad connection. Check the connection in the driver's side kick panel. Also, I've seem lots of damage in rear harnesses from cargo impacts. Also, check your license plate light. Lots or corrosion there (or in the taillight sockets) could be drawing all the juice from the lights.
 
To go a step further, you don't want "low voltage" lamps and in fact they don't exist...except for oddball low use applications, and therefore will be harder to obtain and more expensive, and not available in the types and wattages you would want.

The automotive equivalelnts of 12V lamps were 6-8V for the old 6V systems

Fix the wiring or upgrade it If you are concerned about rear impact, consider adding an aftermarket "3rd lamp" in the rear window........a very bright LED stoplamp that WILL be seen
 
So forgive the sloppy paint photo....but I think this may explain better. Each side has two sockets for 1157 style bulbs. Originally they were wired (per the wiring diagram for the car) as the lower left explains. Green/black for left side and Brown/black for right for tail/turn/brake and purple to other socket for reverse lamp. Now they are wired up like on the right where the green/black LEFT and Brown/Black RIGHT are split to wire to both sockets, which makes them dimmer. The reverse wiring is just hanging with nothing attached now. The only other thing i see in wiring diagram is a license plate lamp which is noted between the black wires of the tail lights which i dont even think is there..gonna have to look for that.

1965barracudataillight.jpg
 
The license light is simply branched off the tail wiring. Tail/ park/ marker

So, looks like you want 1157 equivalent LEDs. If they are dim, check voltage at the bulbs, and fix wiring as needed. "Is it possible" that previous owner painted/ tinted the lenses overly dark?

Bear in mind that condition of the reflectors makes a big difference........and these old girls were NEVER anywhere near as bright as some of the "modern" stuff.
 
If you're getting at least 12v at the kick panel connection, I'd unwrap the wiring in the rear where the taillight wires join the license plate wire and test again there. Inspect the harness from cargo damage too. If there's broken conductors and only a couple still intact, that could be the problem. As mentioned make sure you have good grounds on all the sockets. Just adding a jumper wire as an extra ground is the simplest way to check for bad grounds.
 
Are you sure they are wired in parallel as you have drawn?

If they were in series they would each get 6 volts and be dim.
 
Since they ground through the housing, it would be pretty hard to run them in series and still have the turn/stop lights work properly.
 
Success! thank to everyone for helping me pull my frustrated head out of my you know where. Just ended up being bad grounds at the sockets themselves. cleaned them up and the brightness returned. Still may think about LEDs for them but I got some bad ones that had the China virus, so to speak, a few years ago and they made a mess of things...once the socket grounds were good they are actually fairly bright back there.
 
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