syoo8

I noticed two strange things about my H5 headlamps. They installed by the previous owner. I am hoping someone can chime in.

1) The blue high beam indicator in the instrument cluster illuminates when the high beams are off. When the high beams are on, they are not illuminated.

2) It seems that the "high beam" setting on my car activates the high beam on only one side (I think the right side, I don't remember.) The "low beam" setting activates the high beam on the other side- I think.

Put it another way: when my wife flicks the high beams and I am facing the car, the beams look like they travel left<->right rather than up<->down.

So,
High beam:
L: DOWN
R: UP

Low beam:
L: UP
R: DOWN

(or vice-versa, I forget.)

Questions:

a) Is it possible that my headlamps are poorly adjusted? Or did someone mis-wire the headlamps?
b) Would a mis-wiring of the headlamps cause #1?

syoo8

Second (not unrelated) topic of this thread:

My H5 headlamps feel inadequate to me. Driving to Las Vegas from Missouri, I really wanted more light. Our 996 and Civic emit far more light than the 86.5.

I looked on the 928 Specialists website, and their Xenon headlamp kit seems to be NLA.
928 Motorsports offers a HID headlamp kit.

Is there a 'best practice' for headlamps for our old cars?

jcorenman

Mis-wired I think, somehow the PO got the high and low-beam terminals on one of the lamps reversed?? Can you pull the headlight bucket and post pictures of the backside of the lamp assembly?

And just to clarify: Push stalk towards front of car for high beams, and pull for low beams, correct? (And pull further, against a spring, to flash hgh beams).

H5's are US-spec lights, which means they don't work very well... not enough light down the road, too much glare elsewhere. Retrofitting a HID kit into H5's is a very bad idea, the glare will be miserable for oncoming drivers.

What you want are H4 Euro-spec lights, similar to the 8" H5's but with the Euro-style sharp upper cutoff for low beams, more light on the road and less elsewhere-- which means you can also fit brighter bulbs (we use 80/100w bulbs, with relays, with no glare issues).

The trouble with the 8" H4 Euro lights is cost, around $355 MSRP each, from Porsche-- part# 928 631 101 03. (Check with Roger, or Sunset or Sonnen Porsche for possibly better prices).

Search here for "H4", you will find many threads.

Cheers, Jim

Carl Fausett

We just got more HID kits in stock.

I have bulbs in two temperature ranges, so you do not have to have the projector-white light that some object too if you do not want it. A warmer white is available for a more Halogen-like color.

Alan

The H4's are the way to go - ignore HID options none of them work very well in these optics that are optimized for incandescent bulbs. Especially in H5s its a total disaster for everyone else... even in H4s it is rather bad.

People will say they work... they are just wrong. With correct aim you will have lots of light but will be blinding oncoming motorist with your 'low' beams. This is not only not polite - but it's also not smart.

Jim's right someone swapped the connections on one side - easy fix.

Alan

ROG100

By far the best lights are LHD H4 along with the "Herman Koster" wiring kit which gives pure direct power to both lights.

Makes HID lights look weak and better suited for Barbie's play car.

Carl Fausett

Ouch.

I suggest before you rule out HID in a 928, you should actually drive a HID-equipped 928. Once aimed, they do not bother on-coming drivers and you will not receive "dim your headlights!" flashes from on-coming motorists.

The reflective length of the HID bulb is different, so aiming them down after installing the HID bulb is necessary.

Alan

I have - and No.

H4s with uprated bulbs, local switching relays and a relay solution that allows low+high combo for high beams will give you the very best performance possible - no compromises.

Nothing compares - expensive? - yes.

Alan

76FJ55

I believe your problem is a broken ground wire in the harness to the left headlight. It is most likely broken where it flexes when the headlights are raised and lowered. Unplug the left headlight and check continuity between the plug ground and the chassis.
The reason for the odd behavior of the left light and high beam indicator is that the low beam is being grounded through the high beam filament and also grounding through the indicator bulb on the dash. The indicator is in parallel with the left headlight’s high beam, so that is why I suspect the left ground. If the indicator was working correctly I would suspect the ground to the right headlight.

syoo8

This is brilliant. Thank you VERY much, Simon - I will check this when I see the car again in February.

Alan

Its possible depending on what the exact symptoms really are... but based on what was described - I don't think so - I think a simple wire swap is more likely.

The decription of the Blue dash indicator is odd (but may just be confusion on which is really high beam mode).

For what you suggest one side should be quite substantially dimmer (in both modes) than the other... enough that it would be the very first thing I'd note about the behaviour.

Alan

syoo8

Ah. I see. Well, both sides are more or less the same in terms of brightness. Will be interesting to try to sort this out.

By the way, Alan- did you ever finish your 928 Electrics treatise? I would love to buy a copy when you are done.

syoo8

Finally a conclusion to this topic. Greg Brown figured it out. Each headlamp was wired incorrectly. Easy fix!

Ad0911

Hi Roger,
Do you stock these "Herman Koster" wiring kits? Are thede also beneficial to my Euro-78? How hard to install?

vanster

At one time I had 7" H4's with 55/100 bulbs. They were great but I wanted the look of the 8" light so I bought a set of H5's. Yes they are much better looking but they suck. I have tried various bulbs including HID 's. 80mph on a dark hwy and you have out driven them. Just haven't stepped up to spend $800 on a set of 8" H'4s