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New to AFM - LED headlights on a Classic Stang?

3K views 21 replies 5 participants last post by  Yadkin 
#1 ·
Just got a 66 Mustang, and sorting through fried headlight wiring (and melted switch and connector).
Previous owner had halogen lights -- "...no problem for the past 4+ years"
So, while I am installing relays along with a whole new headlight circuitry, I'm thinking maybe I should just go ahead with LED lights to replace the halogens, at least to reduce the current draw.

I saw one of the vendors wanted over $250 for a set of LEDs, but meanwhile, Ebay has some for $30-50.
I want to retain the old style headlight look, so what do classic Mustang owners use when they go LEDs?

While I'm at it, any opinions on LEDs?
Thanks
 
#2 ·
Melted wiring is usually because someone did something stupid and not because of halogen bulbs.

I would use 60W halogens. There is no LED conversion that I have seen that has a decent light distribution pattern; its almost impossible using a somewhat original looking reflector because of the way LEDs are made. I also doubt that any of the LED conversions are legal anywhere in the world. Claiming to be legal is easy since enforcement of US headlight laws is rare. Being bright is not the same as being useful or legal. Legal halogen bulbs cost less than $10 each, do not use any more power than factory bulbs meaning rewiring is not needed and provide the best possible lighting option when you use them in the correct headlights such as the French Cibie I explain in this thread of mine.

Each headlight uses about the same current as your ignition coil. When did you ever need a relay to supply power to your coil????

https://www.allfordmustangs.com/forums/classic-tech/611745-7-headlights-66-a.html
 
#3 ·

Well, I see on my very first naive post, that I stepped right into a very pet peeve for which you make a strong stand.
I read your entire thesis on the link you provided, and I have to say it seems scientific. (I have to confess that at one point, I caught my mind going "blah blah blah" because it got into an area that I mind was thinking "pseudo-science" only because I had to blindly accept your points -- not interested enough to go out there and do the research myself...)

However, the "myth" is really perpetuated by numerous other internet articles (not confined to the Mustang crowd) that I interpreted as condeming the wiring being beaten by high current over time, and advocating the use of relays -- as well as affidavits from local classic Mustang-only repair shops in the Louisville area (whose opinons, of course, would be experiential and conjecture).

So, you say that my fried headlight Blk/Yellow wire, fried from the switch to the headlight, was due to something else, not the halogen lights.
...and that the halogen lights do not draw excessive current to burn out the wiring.

This was a new aftermarket wiring harnessas 4-5 years old, and with only about 4500 miles, of which 90% had to be daytime driving.
Were you thinking the gauge of wire used was inadequate, or do you have some other likely culprit that I should be focusing on (I think you also have a 66 Mustang, right?)?
I sure do not want to be installing a new harness just to end up with the same result.

Thanks.
 
#5 ·
There are two '66, 289 Mustangs in our garage. One has all its original harnesses but the other has a few AMP repros to replace wires burned out from an engine fire long before I bought that car. We drive the original, A/C coupe on long summer trips every now and again to the midwest and beyond (VA) since that is where we lived until age 21. The coupe is the one with the halogen Cibies since it is more likely to be driven at night, far away from home. My first new car was a Fiat 124 Spyder which now has a similar set of Cibies.

I admit, I piled on the words. :) That thread provides a Purdue EE's analysis of the issue which, I admit, goes against common belief. Common does not mean correct. My version uses the laws of physics to disprove mass opinion. Halogen, by itself, was not your problem at all. Halogens are used for more and better light using the same, or less, electricity than the prior incandescent bulbs used. LEDs are more efficient yet but to generate a lot of light they have to use an AREA emitter and not what is essentially a tiny, point or line source used for halogens. The optics to use LEDs are vastly more complicated and different and you won't find any decent ones for $30 or in any retrofit kit. You may find some LED bulbs that splatter out a lot of light but I have not seen one that produces a decent light pattern for a retrofit application. And keep in mind that high power LEDs run incredibly HOT which is why they have huge heat sinks on them. Especially the el cheapo versions may not be designed for a very long lifetime.

Now, if there were 100 W, or larger, halogens in your car the story would be somewhat different although not greatly. A watt is a watt no matter how its generated. 100 W halogens will always be marked Off Road Use Only since the legal versions will be 55-60 W.

Some of the wiring harnesses you might find today can have really small, inadequate gauge wires; I have seen that problem myself although not with Mustang repro harnesses made by AMP. Undersized wires will cause problems now and forever. I have even seen what were called jumper cables made with 12 ga wire. Useless, except to charge a cell phone since a car battery cable is usually a 2 ga wire or larger. Every starter uses a relay, i.e. solenoid, since starters require a huge number of amps that small wires cannot supply.

Your profile says you are in Alabama? I never expected you to be near Looavul. I grew up listening and watching WHAS and even had my 5 minutes of high school fame in an interview on WKLO for some now-forgotten reason. In those days it was an AM station in downtown Louisville and was NOT into country music.
 
#8 ·
LEDs have come a long way since 2013 or even since 2018.
Here is an excellent source for LED conversions:

LEDs[/QUOTE

GT, thanks for the reference. Have you tried these LED headlights yet?
I also have a concern raised by Ivy in regards to the heat generated. I looked in the back of the headlight buckets, and there is very limited space for airflow for heat dissipation.
I suppose I could drill numerous holes there to improve aeration.
The LEDs that are on that website have an internal fan, but I'm just not sure how much ventilation it provides, nor whether those internal fans have any longevity.

The other type LEDs that I have seen have the ribbons of wire which act as cooling radiators, but I have questions about where they would fit, and if there would be problems if the cooling wires touched body work, for instance burning paint or other damage.
 
#10 ·
From a technical standpoint I could go on for pages about the problems with the claims for those LEDs. Lumen is a unit of power, not brightness. Candlepower or candela is brightness but they don't seem to understand that, etc., etc., etc. From a very basic standpoint, how much current or power do they draw? That is what everyone claims they want to reduce but its never mentioned. Those might draw more power than halogen bulbs for all I know. Those big heat sinks are surely there for a reason. The best industry can now produce is a little over 100 lumens per watt of electricity. With high power LEDs its even less than that. To get 4,000 lumens means at least 40, if not considerably more, watts. That is similar, or more, than a halogen will need. Where is the huge current savings, if there is any?

Lifetime depends greatly upon how much air flow is available to cool the bulbs; that is not mentioned. Even many of the LED house light bulbs from Home Depot will fail at a fraction of their claimed lifetime if they are not in a socket mounted in open air. Put them in a recessed socket, i.e. a headlight bucket, and they will die in a couple of years. I know, I had it happen a few month ago. 10 years ago the LEDs being sold as spotlights for $75 were claimed to last for 75,000 hours. They did not come close to that, and no one today even claims half of that lifetime for the newer ones that are much more durable and sell for $10. Caveat emptor is the legal term to understand.
 
#11 ·
One of the first mods that I make on an old car is relays for the high and low beam circuits. My reason is to reduce the load on the dash light switch and the amperage going through the dash.

The only 7" LED lamp that I would recommend is the Truck-lite 27270C. I purchased a pair for my '74 Fiat project and they are excellent. They were originally manufactured for military use and they are DOT approved. And yes, they are expensive, but you get what you pay for.

I have a set of much less expensive (but not cheap) Chinese made for my '64 TBird build and they kinda suck. First it required major surgery, cutting up the buckets and then the fenders behind them, to get them to fit. Not for the faint of heart and not for a car that wasn't a rusted mess to begin with. In contrast the Truck-lites are a direct replacement for the 7" sealed beams.
 
#12 ·
I have at least two file drawers of seven inch round replacement headlights, many useless.

The album linked below is somewhat chronological. Near the top, the car is on the rack, and the caption says "the lights are not blue". The blue is just a photo artifact. They are also not useful as head lights. They are seven inch H4 halogen. They put light everywhere but on the road. The classic sealed beam had the Fresnel effect on the lens. When they tried to move that effect to the back shell they lost it.

Near the bottom of the album is the current lights. These are multi element, sealed, LED. They incorporate in seven inch round the technology used in current cars. Low beam is a what is referred as a "projection" lens. Light is absolutely cut off above a horizontal line. High beam keeps that and adds a flood light.

These are several years old. The halo is a white ring that I connected to the original parking lights. I have a 73 Mach 1 with a more recent pair. The halo is like I have seen on new vehicles. It connects to both parking and turn signal. In Parking/running the light is white. When the turn signal flashes the light flashes yellow.

https://goo.gl/photos/PPcZpByXAgfp8kTk6
 
#13 ·
This has been some great discussion about headlight options, all collected it in 1 thread, and all experiential.
Makes a decision difficult.

RayDav, (you're not Ray Davies of the Kinks, are you?), Your photo album is pretty neat, documenting the progression of changes as you worked on your car. Quite a transformation that has occurred. Over how many years has this been going on?
Do you presently have a 351? Or still 289 / 302?
While your change to an automatic makes especially good sense to me nowadays, it's kind of contrary to the old mentality, isn't it?
And why don't you have AC? I want/need AC in my convertible. Starting to source a system.
 
#16 ·
Thanks all for the inputs.
I am installing the relay system and keeping my halogens presently, basically since I already have them. Also have worries about the high heat, not necessarily for longevity, but for heat-related damage in the confined bucket space on the Mustang (as well as the legality of LEDs in this day and age of litigation).

I do have one further question, and that is about the fog lights -- should relays be used here also?
 
#17 ·
Halogens don't heat anymore than incandescent. And everything is metal there anyway.

Yes you should have a relay for the fog lamps.
 
#20 ·
Do you own stock in a relay company? :) Why do you think everything needs a relay? Ford never used any because they are not needed. The stock fog lights for a '66 draw a combined total of 5.5 Amps to power BOTH of the fog lights. Again, that's similar current to your ignition coil; where is your ignition relay?

Fog lights have their own wiring that bypasses everything including the ignition and headlight switches. The power comes directly from the battery, always hot, to a special 10 Amp fog light breaker and straight to the lights. The fog switch also turns on the tail lights. Are you going to add another relay for them?

The diagram for the fog light circuit is in the upper left of the attached drawing. There is nothing to be gained by using a relay for them except unnecessary complication.
 

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#22 ·
A micro switch on the dash sending a fraction of an amp in a small wire to signal a relay positioned in a direct line from the power source is always better than running the power in a big wire, through the firewall, to a big dash switch, back through the firewall to the device. That's why modern cars use a "power panel", containing both blade fuses and relays, mounted in the engine bay instead of a fuse box mounted in the dash or kick panel.

Every time you operate a switch with a high amp circuit a little arc jumps from the hot terminal to the load that it is about to make contact to. The arc deposits ionized dust onto the terminals which builds up over time. Eventually the deposits insulate the contacts and the switch stops working. A relay minimizes deposition by having the contacts in a (relatively) sealed environment, along with the fast action of the electromagnet doing the physical movement.

My first car that I was able to drive by myself was owned by my parents for us kids to use. It was a '67 Ford wagon with only about 70k miles on her and a mere 8 years old. The 289 with a large flywheel idled in complete silence and if I had that car today in the shape it was in it would be considered "cherry". It had an odd habit though of shutting off all of the lights while driving at night: headlamps, running lights and dash lights would suddenly and without warning go out. Since I knew nothing about cars back, neither did my siblings, we just assumed that the car was haunted. You and I both know now that it was just a worn-out dash switch (dirty contacts). Had that been a relay system the problem would not likely have occured.

As far as installing a relay in the ignition, you and I both know that the ignition circuit is not fused. Instead the switch and wires are all generously oversized. The reason for this is dependability. Ford would rather have the wires melt in a short than have a fuse blow and leave a mother with her 16 children stall on a railroad track. There's no relay in the circuit for the same reason.
 
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