My headlights are pretty dim. I try not to drive at night. So I'm thinking of ordering a set of H4s. But I noticed that current lights look like Cibie's with replacable bulbs. I'm going to pop them open today to get a close look. Does anyone recognize what I've got here?Click to view attachment

Those are good headlights.Are they sealed beam? Issue may be not enough electrical current or a bad bulb. Check the voltage. Get new bulbs...

Cibié BOBI. A semi-sealed H4 headlight, made specially for the US. DOT legal as it had a glass balloon inside to seal the lens and reflector assembly while still allowing use of normal, replaceable H4 bulbs. Actually pretty good lights. I ran a pair in a Chevy pickup back in the 80s.

So I doubt your dimness is bad lights. Perhaps bad ground, too low voltage (too much voltage drop in the wiring), or perhaps too high of expectations.

Thing is, even decent H4s are not going to be equal to modern headlights. A relay set may help, by getting more volts to the lights.

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Change the bulbs and clean your grounds. Or, buy some of 914Rubber LED bulbs.

Plenty info here:

http://www.danielsternlighting.com/home.html

-Harry

A poor ground is far more likely than insufficient current.
If they're both dim I'd install new bulbs after cleaning the lens and reflector by sloshing denatured alcohol inside.
I had good luck with this method on my Vanagon headlamps.
Go for 100 / 55 bulbs

Sloshing with alcohol won't work on those if the inner globe is still intact. The point of those lights was that the lens/reflector was sealed, and so it would not tarnish or corrode.

I'm not a fan of 100 watt bulbs with stock wiring, they pull a lot of current through some rather small wires.

These headlights ended up being in great shape. Took them out, cleaned them, popped into FLAPS for a fresh pair of 55W H4 bulbs, tested voltage at 11.7 at the connector with engine idling, even gave the black trim pieces a fresh coat of paint. The rubber boots at the back were soft and pliable, like new. It isn't dark yet, so can't test for brightness and aim, but they've got to be better than they were. Now I can't wait to mount my Cibie Iode fog lights. A matched set it will make.

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That's a great loooking car! i have a new set of those Cibie headlights but the Euro version without the glass bubble around the bulb. Hopefylly they'll work well with 914 Rubber's LED bulbs I just received.

They should work very well. Do a before and after if you can. I think these are the best housings I've seen so far.

correct about current draw....add relays

Also check out Daniel Stern's site as recommended above. Here's a link:

https://www.danielsternlighting.com/tech/relays/relays.html

An excerpt:

"Headlamp bulb light output is severely compromised with decreased voltage . . . ." If bulb output is 100% at 13.2v, then ". . . when operating voltage drops to 95 percent (12.54v), headlamp bulbs produce only 83 percent of their rated light output. When voltage drops to 90 percent (11.88v), bulb output is only 67 percent of what it should be. And when voltage drops to 85 percent (11.22v), bulb output is a paltry 53 percent of normal! It is much more common than you might think for factory headlamp wiring/switch setups to produce this kind of voltage drop, especially once they're no longer brand new and the connections have accumulated some corrosion and dirt."

Using his info and your operating voltage (11.7 volts), you're only seeing around 60% of your spec'd light output (55 watt low beam x 0.60 = 33 watts).

He has lots of good info there, including a discussion on the relationship between "resistance" (like in dirty/old/bad connections) and heat (fried switches/wiring/relays).

Hope this helps!

Steve A-

BTW, those are GREAT headlights (nice car too)!

Steve, GREAT info. Looks like I should track down my voltage drop. It'll be dark here in 30 minutes. I'll report back what I find.

So....headlights are dreadfully dim. And I couldnt adjust them high enough before the top adjustment screw bottomed out against the inside of the headlight housing. So the fix for that is easy, just cut the screw a little shorter. I can't really adjust that via the position of the headlight's movement since it will then be too high in the rest position, right?

The dimness problem I'll need to track down. First I'll try my grounds. If those are good, then it's a bad switch or tired wires?

Put new battery connectors on, a new negative lead to the chassis, cleaned both headlight grounds back to shiny brass and I'm still only getting 11.7 V at the headlight connector.

I did a voltage drop test ala Daniel Stern and I got 3V total drop from battery to the lights (lights on, engine running)

Also tested my voltage at the battery. It's 12.7 at rest, but not any better with the engine running. My alternator was recently rebuilt, just a month or so ago. Car has original voltage regulator. My dash bulb does work, lights up and goes off just fine.

I read somewhere that the alternator shouldn't be run unless it's connected to a battery. I test ran this engine on a stand last month but only hooked up the starter and fuel pump, I don't remember hooking up the alt to the battery.

What should my next step be?

I ended up buying a new voltage regulator. Now I'm getting 14V at the batt with the engine running. So that's good. Cleaned the grounds up front and now I'm getting 12.5v at the headlight plug. Lights are way better than before, but not exactly confidence inspiring. 55w h4's, brand new bulbs. It's totally drivable, but brighter would be nice.

Now that you have power and ground worked out, you could try higher wattage bulbs, preferably with relays to prevent overloading the headlight switch and dimmer relay. But in my experience, once you have full voltage going to the lights, the difference between 55/60 watts and 80 or even 100 watts is actually pretty hard to tell, and the hotter bulbs have a much shorter life span.

As I said above, it's going to be really hard to make 7" lights in a 914 perform even close to modern expectations. Today's HID and LED lights are much better lights. You may see some improvement by putting LED bulbs in those housings, but since the housings were designed for halogen bulbs, you still won't get light output that is on par with modern cars. The light housings are not optimized for newer light sources.

I'm leaning towards LED's from Mark at the moment. This time of year its really easy to head out for the evening and end up driving home in the dark. Buddy hit a deer in his '71 911S a couple months ago, so this topic is at the forefront for me.