1986 Porsche 911 headlight

[86 911]

Hi everyone,
I am new to this forum. I have recently purchased a 1986 Porsche 911 Cabriolet, and I am having headlight problems. When I turn the lights on, the passengers side light is dimmer than the drivers side light. I have gone to Napa Auto parts, purchased 2 new Hella H4 bulbs and installed them, but the passengers light is still dimmer than the drivers side light! Both lights look extremely clean.
Here is some background info on the car:

1986 cabriolet body w/ turbo look and BBS rims
1976 911 frame
1978 ? Porsche 911 SC 3.0 engine (engine # 930/04)
targa conversion to cabriolet

Also ,the owner that had the car before the owner that I bought the car from had the 3.0 engine rebuilt, and it currently has 40 K miles on it. Which year is the engine number 930/04 from? I am assuming 1978 or 1979, but I am not sure. A photo of the car is attached.

Thank you,
all help will be appreciated,
Matt

[zbph10]

For the headlight issue find someone that has a voltmeter and check the voltage going to the bulb sockets.

If they are the same your problem could be the bulb/lens/reflector.

If they are different check for loose or corroded wires/sockets/connections/high resistance grounds.

Engine information
930/04 78-79 USA SC 180HP@5500 8.5:1 39mm Ports

Nice looking car, enjoy it.

[djmcmath]

Congrats on the new car, and welcome to the board!

Something else you might check, while you're looking at headlights, is the headlight relay kit. It's a pair of relays that you wire into the fuse box to remove most of the electrical loading out to a set of relays that can actually handle the load.

Have you swapped lenses, reflectors, or bulbs, from one side to the other? That might give some more indication...?

Dan

[Bob's Flat-Six]

What happens if you hit the high beams?

[86 911]

Thank you for all the responses!
If I turn on the high beam, the passengers light is still dimmer than the drivers side. I have not swapped lenses, reflectors, or bulbs from one side to the other. I am about to go in the garage and take a look at the fuse box and check the relays for the headlights, and do what djmcmath and zbph10 suggested in the previous posts.

Matt

[911mot]

Locate the earth terminal in the headlamp multiplug and run a fly lead from it to the battery negative pole.
If the headlamp is now bright you have an earth problem.

[86 911]

When I looked at the fuse box, I saw that fuse #5 is missing the upper wire. This may be the problem. I also looked under the light switch in the car and I found that the wires were taped with electritians tape. I will check the ground later and see how many volts both headlights currently have.

Thanks,

Matt

[djmcmath]

Ooh. Electician's Nightmare. It could be a long dark road ahead, full of gooey masses of electrical tape wrapped tightly around crudely spliced masses of wiring, trying to track down one intermittent electrical signal.

(ahem) But I'm sure you'll have those headlights up in no time.

Dan

[Por_sha911]

This may be a dumb question but did you check the alignment to see if the dimmer light is aimed lower? Check out the relays and check your wiring.

[86 911]

Joe, "did you check the alignment to see if the dimmer light is aimed lower?". This is not a dumb question at all. In fact I have not taken off the headlight to check anything yet, so I do not know about the alignment.

Dan, I wish that I could share a smile with you at this moment!

911mot, I have not checked the ground wire yet to see if it is the fault in this situation yet.

Brian, the bulb and lens reflector looked in very good shape when I added new bulbs a week ago.

So far what I have done today is check the fuse box (with the help of my Haynes manual), and tried to switch the high beam and low beam fuses (fuse #5 and #6), but I had no luck in identifying if the problem is in the fuses since the car is not original and has been rebuilt, so the fuses are different than stated in the book. Tomorrow, I will call my friend who knows a lot about electrics, and hopefully I can bring the car down to his place, and he can take a look at the configuration. If not, then I will spend a few hours tracing wires from the headlight to the fuses, remove the fuse box to get a good look at the wires, and then I will know which wires are causing the problem.
Also, does anyone know if the lens of the headlight act as a ground?

Matt

[RoninLB]

Originally posted by 86 911
.
Also, does anyone know if the lens of the headlight act as a ground?

the lens should be glass. The headlight frame is not used as a ground. The ground should be the tub.

[ChrisBennet]

Originally posted by 86 911

Here is some background info on the car:

1986 cabriolet body w/ turbo look and BBS rims
1976 911 frame
1978 ? Porsche 911 SC 3.0 engine (engine # 930/04)
targa conversion to cabriolet

Where your car has a mix of years make sure you include the year of the associated system (electrical, brakes, transmission, suspension) so we aren't scratching our heads looking at an '86 wiring diagram when you have a '76 wiring harness or vica versa.
-Chris

[Paulporsche]

Welcome.

I had this problem some time ago. I think one of the screws holding the housing into the bucket was loose. When I tightened it, it must have made a better ground and the lamp returned to its normal brightness.

Sorry I can't give you a better explanation. I wasn't even sure @ the time what it was...it just worked.

Let us know what works.

[86 911]

I am not sure what year the transmission or wiring is from, but I think it is from a 1976. I did not have much time to get anything done today, but what maybe the problem is that fuse #5 is missing the upper wire as well as another fuse further up the box. Paul, tomorrow I will try to tighten the screws that hold the housing into the bucket as you suggested.

Thanks,
Matt

[Paulporsche]

Try pushing on , twisting, tightening, cleaning etc anything that might complete a ground.

[TerryH]

The 930/04 is 49 state compliant. That's not great if you live in CA. It must of been smogged to change owners, so maybe there aren't any issues to worry about.

[86 911]

Terry, I hope there won't be any issues to worry about with smogging, and the new California law that is bieng taken in consideration.
Paul, I will tell you what I find out tomorrow. I think there may be something wrong with the ground as you suggested. I am going to bed now and I will try to post more tomorrow afternoon,

Matt

[Wil Ferch]

From the "other" post you have going on currently...it is apparent that you have a 76 car...not an 86 as you guessed. hope you didn't overspend to get this car.

As such, look at 76 wiring set ups. I notice that the fog lights in your original picture are of the 78-83 3.0 body style variety....and not of the 84-89 Carrera variety...lending more credence to your car being a mid 70's vintage. Check VIN's to make sure.....

--Wil

[86 911]

Wil,
The car's VIN number is from a 1976, although when advertised, the seller said the car has a 1986 cabriolet body with the turbo look, a 3.0 engine and a 1976 911 frame. I paid $13K for the car. It looks great except for a few paint blistes and scratches and runs great. What will it take to upgrade my 79' 3.0 engine for it to gain about 40 H.P and look like a 1986?

Matt

[Wil Ferch]

The only visual clue as to an 86 ( turbo-look cab)...would be the updated front lower valence that has the fog lights more integrated than what you have. Off the top of my head, I can't think of any other visual clues.


40 extra hp? Tough......maybe SSI's and a sport muffler..that would get you about 17-20....the remaining 20 will be tough.

Wil