ew928

I used a set of JCWhitney bluish bulbs once. (Ashamed to admit)
One of the bulbs had a nice fingerprint etched onto the quartz/glass and I had not touched the bulb glass at all. T'was handled before I got the bulb. Now I wipe down all the bulbs I get with alcohol.

I've never dared run the 100/80 bulbs.

jheis

I've been running 100/80w bulbs in my '82 for at least ten years with no problems. I just replaced the old Osrams with a pair of Hella Xenon Blues. The Hellas seem to have a more defined cut-off for some reason. I'm getting flashed at less often when I'm on low beam.

James

Alan

I have 80/100 Silverstars.

Hella, Osram, Philips etc all good

ACG

I am using the Hella Xenon 80/100 with no modifications to the wiring. The lenses are also the Hella E-code. No issues so far!

BrianG

I just converted my '87 S4 to H4 HID, and there is something flakey in the wiring to the headlamps. As you may know, aftermarket HID kits take their hi-lo signal from only 1 of the 2 OEM headlight bulb sockets. I discovered that there was about 6v supplied to the hi-beam circuit if one of the sockets was not connected to a load (headlight bulb) and it didn't matter which one. This caused the HID unit to fail to drop out of high-beam when low-beam is selected. If I cycled the headlight switch (turned the headlights off) with low-beam selected, the HID resumed low-beam operation. High beam selects as expected.
I discovered that if you place the bulb back in the empty headlight socket, the HID cycles properly.

This leads me to believe that one of 2 things exist in this car. Either the light monitoring circuit is somehow responsible for this 6v feed, or this is actually a safety feature, where the hi-beam circuit is fed 6v (for low light output) when the system sees an open low-beam circuit. This would provide a falied-side marker lamp with the half-powered high beam element.

I accounted for this phenomenoon by adding a 5 ohm 50W heat-sinked resistor to the unused low beam socket, and the HID is now working fine.

Alan

Makes no sense to me at all....!

There is no 6v supply anywhere - if you see 6v something is going wrong... for a diagnosis you'd need to provide more info - but it isn't working correctly as it should.

Alan

dr bob

6V shows up when the ground at the bulb is open. +12V on one filament, cross-feeds through the other bulb opposite filament to ground there. (hip shot/guess...)

Alan

Exactly my point earlier... something is wrong to see this.

But in the case of the HID system there are no regular dual filament bulbs...

Alan

ew928

Saw a dual HID kit on Ebay some time ago. As in HID low and HID high kit with dual bulbs and dual igniters.
Didn't look like you can squeeze the 2 HID bulbs close enough to approximate the small difference in location between the hi/lo bulb filaments in a normal incandescent bulb. And the thought of waiting for the HID's to fire up everytime you switch from hi to lo and back didn't thrill me. Of course it nearly cost twice as much as a normal single HID kit.

So you get 6V if you use the high beam '+' as a ground . . .
Interesting.
I did mod some 9007 bulbs to work in a 9004 environment ages ago. That uses a flipped ground and high beam '+', I think. Filament orientation was wrong (front back instead of side to side) but the 9007's were 55/60 instead of the 45/60 on the 9004's. And I run low beams often.

Tampa 928s

I guess I'm not crazy after all, the 6 Volts was there on the panel when the lights were tested and bulbs not working.

After reading up on the Xenon bulbs it's says it's not a direct replacement for the factory headlamps. I replaced the Whole unit with a H-4 lens using the 100/80 Xenon blue bulbs keeping stock wiring.
What I'm reading is that an upgrade including relays are required and should not be used this way.
I wondering if I should send both lenses and bulbs back and start over. I'm not prepared to add a HID lamps anytime soon or am I reading too much?

Alan

What you want to do should work just fine...you just need to make sure everything is connected normally. You don't need to think about HID bulbs.

The exact same connections that appear at the back of the bulb connectors are the ones you referenced on the CE panel. They can't be 12v at the bulbs and 6v at the CE panel... not possible.

Just get good quality bulbs and work through it methodically.
No rocket science. The headlight circuits are much simpler than they appear in the schematics - once you strip away all the pod motor stuff and fog/driving lamp stuff.

Alan

Bill Ball

Since you switched from H5 to H4, you must have spliced in an H4 plug. Do you have that wired correctly? Alan and dr. Bob are suggesting you have a ground issue. No relays and extra wiring are needed for 100/80s. I'm another who has run these successfully in a H5 to H4 conversion for almost 7 years.

One thing that is confusing is that the H4 housing has 4 prongs, while the H4 bulb only has 3 (hi, lo, ground). The 4th prong is unused, and I don't think there is any way to wire this incorrectly as the H4 plug only has 3 prongs and will only go on one way.

Tampa 928s

Bill,

My is an 86 used the old sealed beams, I added the H-4 lenses and the 100/80 H-4 Xenon blue bulbs. The lenses are fine but the factory wiring remains in place with no modifications. Some members prefer the blue some white I need to replace both so I'm trying to purchase the correct set of bulbs with out burning them out again. I saw no indication of wires melting or had any issues until both bulbs burned out simultaneously. There was an actual bubble in the top of the lamp due to heat I believe.

Bill Ball

Ooops! Sealed beam to H4 is a direct drop-in. Nevermind.

I've used Hella clear 100/80, bought at the local auto parts store (behind the counter, specified for off-road only) as well as a number of the blue-tinted 100/80s. You know, the blue tints are kind of stupid. The glass is tinted to emulate the higher color temperature of HID, filtering out the lower heat range wavelengths. Yes, the light emitted looks "whiter" than clear halogens, but inherently the blue filter means less light is emitted. The ones you show look very heavily tinted - they look almost opaque. Either go with clear or a set that has a lot less blue tint.

dr bob

Bill--

That housing you show looks like it's set up for "city lights", feature that's popular in many of the civilized spots in the world. At night in city stop-and-stop traffic, no need to have the main headlights on. A little aux bulb gives the whole housing enough glow to let folks see that there is a car there. The late BMW's with the HID's implement this as the white ring-around-the-low-beam. Thge look would be way cool on a 928 with the lights in the daytime position, IMHO.

Of course I'd probably get a ticket if I tried it, though.


I had thought about adding that as white LED's around the perimeter of the existing glass envelope. That would be in addition to the array of IR LEDS pointing across so that IR laser speed detection devices would have to choose something other than the headlights for a target. Of course.