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H4 Headlight Upgrade

Discussion in 'Early CJ5 and CJ6 Tech' started by Renegade ll, May 16, 2019.

  1. Renegade ll

    Renegade ll Member

    I know this has been discussed, however I want to ask a few questions. First off my headlights are stock for my 1971 cj5. I have added relays for the low and high beams. Do I just buy the 7" round headlights that have the H4 bulbs and plug them into the 3 prone plug? Do I need to make any cuts in the headlight buckets? Is the upgrade noticeable?
     
  2. PeteL

    PeteL If it wasn't for physics, and law enforcement... 2024 Sponsor 2023 Sponsor 2022 Sponsor

    You will notice. No one else will care.
     
    Twin2 likes this.
  3. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    Yes. No. Yes.
     
    Focker likes this.
  4. Posimoto

    Posimoto Hopeless JEEP Addict

    i bought a conversion setup from Summit Racing. It was pretty straightforward. All plug and play, no cutting. It went into a '66 CJ
     
  5. Keys5a

    Keys5a Sponsor

    H4's are a big improvement, and they will work plug & play. I would recommend the relay upgrade for both regular sealed beams and H4's. Some of the cheap offshore brands work well, but are not the quality of Hellas.
    -Donny
     
  6. NCRenII

    NCRenII yellow fever

  7. Rick Whitson

    Rick Whitson Detroit Area 2024 Sponsor 2022 Sponsor

    I don't use my headlights much, don't drive at night, are you saying the relay that came stock on my Jeep is not strong enough for stock head lights? I have extra original head lights, American made, so I don't think I will ever run out of them, plus the ones in my Avatar work, so I could use them if I had too. I had a 62 Vett, I put Aircraft landing lights in the High Bean side, they would draw so much power that the relay would open and out went the light when the relay got hot, Scary stuff.
     
  8. timgr

    timgr We stand on the shoulders of giants. 2022 Sponsor

    What you describe seems more like circuit breaker behavior than relay. There is no headlight relay on a factory CJ-5. There is, however, a thermal circuit breaker that protects the lights circuit, and there could have been a similar breaker on your Corvette. The thermal circuit breaker is ideal for this application because it will reset by itself when it's been off for a while. It will cycle on and off if the short circuit or overload is not corrected.

    The factory headlight wiring is all directly wired through the circuit breaker, headlight switch and high beam switch, plus about 10' of smallish gauge wire, and the ground returns through the steel body. Adding relays makes the bulbs brighter because it substitutes a large gauge feed wire to the relays for the factory switches and wires. This reduces the resistance between the battery and the lights, and raises the voltage to the lights (by Ohm's law). The relay contact resistance is also lower than the switch contact resistance, typically. With the high-power bulbs, you need the relays because the factory wiring and switches are inadequate for the higher current demand.
     
    Last edited: May 17, 2019
  9. Mcruff

    Mcruff Earlycj5 Machinist

    I put Halogen sealed beam lights in my cj5 in about 2005 when I put the EZ wire harness in. That harness had relays and with the Halogen bulbs probably improved light output 40%. It alone is a fantastic improvement over the factory sealed beam lights.
     
    sterlclan likes this.
  10. maurywhurt

    maurywhurt Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    Check out the photo below. On the passenger side is a stock (Westinghouse) sealed bulb headlight, and on the driver's side is a Wagner H6024 Halogen sealed unit. The Wagner bulbs do not need a relay, and plug into the stock wiring harness (though I should mention that my original 1967 harness was recently replaced with a new one from Walck's, and the original light switch was replaced with an NOS one from Debella's).

    Though the two bulbs look pretty much identical when turned off, when they're turned on there's a very significant difference in the amount of light output:

    [​IMG]

    I was looking for something else on Rock Auto this week and found these Wagner H6024 headlights on closeout for under $5 apiece. Here's the link:

    1967 JEEP CJ5 3.7L 225cid V6 Headlamp Bulb | RockAuto
     
    Last edited: Jul 9, 2020
    homersdog likes this.
  11. Focker

    Focker That's a terrible idea...What time? Staff Member

    I don't think many do, but the relay helps prevent dimming at idle and brightening when hitting the gas pedal.
     
  12. Mcruff

    Mcruff Earlycj5 Machinist

    That’s about the difference that was made on mine between relays and sealed halogen bulbs from the stock lights.
     
  13. 47v6

    47v6 junk wrecker! 2023 Sponsor 2022 Sponsor

    I use the halogen ones too. Didn't even consider the stock ones. Bought the correct plugs, wired up up, used the stock cj2a switch and they work great.
     
  14. maurywhurt

    maurywhurt Member 2024 Sponsor 2023 Sponsor 2022 Sponsor

    My halogen bulbs don’t seem to dim noticeably when idling. Would the fact that I’m running a 55 amp alternator tend to reduce dimming at idle?
     
  15. Focker

    Focker That's a terrible idea...What time? Staff Member

    That sounds like a good guess. Without relays the current is passing through the switch. With relays, the power is directly pulled from the battery and your switch activates the relay.

    How To - Install Headlight Relays
     
  16. Buildflycrash

    Buildflycrash More or Less in Line. 2024 Sponsor 2022 Sponsor

  17. Renegade ll

    Renegade ll Member

    Thanks guys.
     
  18. Mike C

    Mike C Member

    I put the Hella H4 lights in my A1, in my MB, and in my '79 CJ-5. They plug right in, look great with real glass lenses and dramatically improve the lighting for $75.
     
  19. Henri Watson

    Henri Watson Member

    I'm thinking of doing the same thing after I get my relays wired in. Wanted to ask, are there any plug-in LED bulbs that work with the factory reflectors that someone can recommend or does it require a new bulb/reflector combo? Only reason I'm interested in LED is because they would then match my auxiliary lights. If not I'd be just as happy to go with H4s.
     
  20. jeepermc

    jeepermc Active Member

    Those look like they will throw light in every conceivable direction. Usually fine for the guy sitting behind them, but for oncoming traffic it's terrible. I had a set of aftermarket clear lights in my fox body mustang for awhile. In the rain you could basically see a wall of light going straight up in front of you because of the terrible reflector design they had. Light everywhere. I'd be curious to see what yours do with the light with all the refraction angles in the reflector.