Brake light bulbs

69mopar man

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My 69 owners manual says use only brass base bulbs , however I can’t find any? Will it hurt to use todays cheap bulbs?

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Ross Wooldridge

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It's the dissimilar metals thing, and for whatever reason, compared to brass base bulbs the aluminum base bulbs react very poorly over time and corrode themselves into a big non-conductive hard to remove mess.
 

Ross Wooldridge

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It is, and I thought about that, but it's also an INSULATOR, which by design will minimize the contact between the bulb and the connector... and whatever connection is made will be the place where all the corrosion will be...

It also depends upon the style of the base of the bulb connection - if all the connections to the bulb are through the lead spring loaded tabs, INCLUDING THE GROUND, then you could likely get away with dielectric grease and an aluminum base bulb, but I think almost all of these connectors use a locating pin for the ground... and there's your corrosion point.

There is conductive grease out there, but I don't know about its application in this situation, and it may just close the circuit without permitting the current to flow into and out of the bulb.

Brass based bulbs are still out there.
 
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Turboomni

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With so many Edison bulbs in our 69 Furys I would notice ammeter would really go to negative when pushing on the brakes and worse when the headlights were on. What are there 4 or 6 bulbs that light up in the tail when you depress the brake pedal?? ,I don't remember but alot. Also in the daytime I wasn't really happy with how bright the stock bulb tail lights were. I considered an upgrade to LED type and needing a different flasher and this and that kinda made me yawn. I replaced all the tail light bulbs with LED lights only and all the front bulbs are all Edison type. Much brighter tail lights [I did remove the housings ,cleaned them and shot the reflectors with reflective paint] the ammeter hardly moves [doing a bypass this year anyway I hope] and the front Edison bulbs as well as the fender turn signal indicator lights were markedly brighter. No led flasher needed as it flashes as it should with a normal flash rate. Just a thought.
 
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CBODY67

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As always, the light housing's reflector is an important issue to consider. MORE than many probably suspect.

I noticed that GM replacement bulb sockets came filled with a brown, viscous material from the factory, from the earlier 1990s. At the time, I suspected it was some sort of anti-corrosion AND heat sink material. As all dielectric silicone was waxy opaque clear, by comparison. The particular sockets accepted the flat-base 3157-style bulb, although the round base bulbs also had it in them.\

A few years ago, I ran across some YouTube videos on bulbs. One used an IR heat gun to measure the temp at the bulb socket, which was right at 300 degrees F. Yikes! No wonder all of those 2000s GM pickups had burnt sockets on their daytime running lights! And those sockets were all "dry", too.

Just some observations,
CBODY67
 

live4theking

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It's the dissimilar metals thing, and for whatever reason, compared to brass base bulbs the aluminum base bulbs react very poorly over time and corrode themselves into a big non-conductive hard to remove mess.
I would use De-Oxit to prevent this. It's purpose is to prevent the reaction of dissimilar metals.
 

Ross Wooldridge

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That's a good suggestion... but how long lasting is the application of DeOxit?

I know it eliminates existing corrosion and does add some corrosion protection, but I don't know how long lasting it is.
 

SPF Required

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I went through and did a lot of LED bulb swaps in my ‘68 300. I even did the instrument cluster because I needed to pull it for a speedometer fix. I could not be happier with how bright everything is. I did swap out the flasher relay with a grounded one, but it wasn’t a tough task (had to reverse the wires in the connector though).

Kept the headlights stock but even they are brighter and don’t pulse when I am at idle.

No no one told me about the dissimilar metal thing, so I hope I don’t regret it in the long run, but that is a problem I will have to tackle later.
 
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Turboomni

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Now no one told me about the dissimilar metal thing, so I hope I don’t regret it in the long run, but that is a problem I will have to tackle later.
I am not arguing the dissimilar metal thing but there is another difference between Edison bulbs and the new Led type besides the increased amount of light only , it is their efficiency which equates to much lower operating temperatures which may make the dissimilar metal thing much less of an issue or ideally a non issue. I do not know.
 

CBODY67

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One thing about LEDS that I have not fully understood is that with all of their electrical conversion efficiencies, the headlight bulbs have little fans in them to keep the bulbs cool. And the signal light bulbs and such also produce as much heat as an incandescent bulb does, from what I've found out. Plus, those "resistor loads" (to prevent hyper-flash) can also get that hot, too. FWIW.

Perhaps, some day, those mysteries will be revealed?

CBODY67
 

Gerald Morris

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That's a good suggestion... but how long lasting is the application of DeOxit?

I know it eliminates existing corrosion and does add some corrosion protection, but I don't know how long lasting it is.
NoAlOx, DeOxit and such last a good long time, in stable environments. I reckon one of these anti-redux dopants would help preserve one's light sockets from Al->Fe bonding. I might avail myself of the stuff, now that I think about this, as I've gone to LED bulbs all over. The Desert is Kind, but monsoons aren't. I might recommend NoAlOx as the first choice for this purpose, as its designed to preserve houses from those nasty Al+Cu fires. My Sainted Mother lives in such a house, built in 1967. Yeah, NoAlOx is probably the best bet here....
 

Gerald Morris

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One thing about LEDS that I have not fully understood is that with all of their electrical conversion efficiencies, the headlight bulbs have little fans in them to keep the bulbs cool. And the signal light bulbs and such also produce as much heat as an incandescent bulb does, from what I've found out. Plus, those "resistor loads" (to prevent hyper-flash) can also get that hot, too. FWIW.

Perhaps, some day, those mysteries will be revealed?

CBODY67

The business of LED headlamps is an easy problem to explain: the asshole manufacturers make them for the SAME, or MORE POWER than the incandescent bulbs, which is CRIMINAL in My Book. They pander to a Market for Excess instead of Efficiency. Thus, I eschew them.

The trick with LED signal bulbs is to get the electro-mech flashers, to prevent hyper-flashing, OR, leave ONE incandescent bulb in circuit as a resistive load, if you really MUST use thermo-flashers for sentimental reasons. To my knowledge, and experience, the LED signal lamps and such really do run cooler, though I have felt some heat off them. I might rig a test up just to see how much heat some of these generate....
 

Gerald Morris

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I am not arguing the dissimilar metal thing but there is another difference between Edison bulbs and the new Led type besides the increased amount of light only , it is their efficiency which equates to much lower operating temperatures which may make the dissimilar metal thing much less of an issue or ideally a non issue. I do not know.

IDK for sure myself, but my experience has been these past 5+ years that the LED signal and dash bulbs do run cooler, and I've seen NO signs of Al redux bonding such as worried (RIGHTLY!) MoPar and other electrical designers 50 yrs ago, when fires happened as a result of all the aluminum conductors then newly introduced to a copper paradigm market. When I run LEDs, I never use the load resistors, which totally defeat the purpose of using LEDs BTW, but use modern flashers meant for LEDs. I have NO electrical problems with my Landboats once I wire them to my specs.
 

Gerald Morris

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I would use De-Oxit to prevent this. It's purpose is to prevent the reaction of dissimilar metals.

Is De-Oxit just a preventative or will it remove some of the Al2O3 from an already partly compromised socket? I've only used NoAlOx on wire and terminations, though if I SEE any sings of redux in my sockets, I'll sure as shit use it then.
 

live4theking

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That's a good suggestion... but how long lasting is the application of DeOxit?

I know it eliminates existing corrosion and does add some corrosion protection, but I don't know how long lasting it is.
I would think in a closed up situation like a bulb socket that it would last for sometime. I put it in my bulkhead connector and when I took that apart a couple of years later it was like I put it in there 5 minutes ago. It's about the consistency of vasoline.
Is De-Oxit just a preventative or will it remove some of the Al2O3 from an already partly compromised socket? I've only used NoAlOx on wire and terminations, though if I SEE any sings of redux in my sockets, I'll sure as shit use it then.
I believe that it will work in both situations. It's always key to start with as clean of a connection as possible. Where I work we use it as preventive. On my old C I've used it for both purposes.
 

69mopar man

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Thanks everyone for all your valuable info , but I’m not an electrician so bottom line is ? To just replace my old bulbs with the current LED bulbs? If there’s wire modifications I’ll have to take to a shop, I had rust in my bulb holders that were spring loaded and I used rust gel and cleaned them up , I’m keeping my old headlights because I like the look , prolly never drive at night , I just want something for brake lights that will work and not overheat
 
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