928 LED headlight conversion question
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From: Portland, Oregon
https://www.headlightrevolution.com/...s/gtr-csp-mini
Also:
- as Michael Benno previously posted, it may be necessary to replace the standard foglight relay with a "Bosch 53",
otherwise there may be a problem with the foglights not working correctly
- depending on the year of your car and the part number of the existing bulbs, you might need a "9004 to 9007 adaptor pigtail" check with the tech when you call
.
Last edited by GUMBALL; Apr 2, 2022 at 04:15 PM.
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I put LEDs in my fog and aux hi-beams and into my headlights in my 81 and had no issues with fog light behavior. Maybe the relay swap is required for newer cars than my 81 was, although I hear the relay "problem" means the fog lights and aux hi-beams stay on together - that would be ok too.
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I use Holley Retro Bright headlights in my vintage vehicles. WOW what a difference! Not only period correct looking but the highest rated by Headlight Revolution and provide perfect beam pattern. Installing a set on my incoming GTS. (They ROCK in my DeLorean)
Great alternative to JW Speaker.
https://www.holley.com/products/exte.../parts/LFRB155
Great alternative to JW Speaker.
https://www.holley.com/products/exte.../parts/LFRB155
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Thread revival - I am getting a set of H5 headlights, larger size without the chrome rings. My 85 currently has the 7" lights with the chrome rings. Is an adapter kit needed? Plug and play? I seem to remember a DIY fix to replace the 7" headlights with 8" H4's, but I can't find that thread, and I'm not sure the same steps would apply to 8" H5 anyway. Also, I am not spending the $$$ for H4's. This is more for looks than performance. I don't drive much at night.
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Thread revival - I am getting a set of H5 headlights, larger size without the chrome rings. My 85 currently has the 7" lights with the chrome rings. Is an adapter kit needed? Plug and play? I seem to remember a DIY fix to replace the 7" headlights with 8" H4's, but I can't find that thread, and I'm not sure the same steps would apply to 8" H5 anyway. Also, I am not spending the $$$ for H4's. This is more for looks than performance. I don't drive much at night.
Where does one even buy 8" headlights?
Electron Wrangler
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You will need to replace the connectors. Something like this https://gowesty.com/products/headlig...52102333792624
You can buy 7" H4 Euro headlights many places that use 9003 bulbs - these are relatively inexpensive even from high quality brands (Bosch/Hella/Cibie). 8" H5 (USA DOT) and 8" H4 Euro lamps are available new but neither are cheap. H4 Euro lamps are preferable - they have much better optics. But both 8" lamps do look much better aesthetically (no chrome rigs). These are manufactured by Bosch (glass lenses). All H4 lamps use H4 connectors (& 9003 bulbs available in various configurations). Generally they handle uprated power well. US DOT H5's (& various 9004 bulbs) do not handle uprated power well at all - you will just blind everyone else with scatter. Because of the configuration of cars sold in the USA used 8" H5's are far more available than used 8" H4's domestically (the reverse is probably true elsewhere in the world).
From a lighting performance perspective (Best) 8" H4 -> 7" H4 -> 8" H5 -> 7" DOT sealed beams (Worst). The H4's are quite noticeably better. For 8" H4s/H5s try Porsche dealers or Roger at 928sRus, for used occasionally 928Intl. New H4s are about $685 each.
Alan
You can buy 7" H4 Euro headlights many places that use 9003 bulbs - these are relatively inexpensive even from high quality brands (Bosch/Hella/Cibie). 8" H5 (USA DOT) and 8" H4 Euro lamps are available new but neither are cheap. H4 Euro lamps are preferable - they have much better optics. But both 8" lamps do look much better aesthetically (no chrome rigs). These are manufactured by Bosch (glass lenses). All H4 lamps use H4 connectors (& 9003 bulbs available in various configurations). Generally they handle uprated power well. US DOT H5's (& various 9004 bulbs) do not handle uprated power well at all - you will just blind everyone else with scatter. Because of the configuration of cars sold in the USA used 8" H5's are far more available than used 8" H4's domestically (the reverse is probably true elsewhere in the world).
From a lighting performance perspective (Best) 8" H4 -> 7" H4 -> 8" H5 -> 7" DOT sealed beams (Worst). The H4's are quite noticeably better. For 8" H4s/H5s try Porsche dealers or Roger at 928sRus, for used occasionally 928Intl. New H4s are about $685 each.
Alan
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I'll post for a bit of nostalgia. I bought my 83 car in 1987 and one of the very first things I did was upgrade from the 7" sealed beams to the 7" H4s. Huge difference, and the 7" H4s were readily available at many parts stores and quite inexpensive. They had the classic and fantastic H4 pattern, horizontal on the left and angled up on the right. However, compared to another car I had at the time - a 1978 Saab Turbo that had quad headlights, naturally all of which I had upgraded to the H4s as well -- the combination of two 7" H4s still left a lot to be desired, especially on high beam.
Within a short time thereafter I abandoned the 7 inchers and purchased a pair of 8" H4s from, of all places, my local Porsche dealer, sold for off-road use only at the time. $300 for the pair in 1987. A nice increase in light output. And a HUGE difference in looks. This is the way the car was intended to look!!
I'm still running the car with that same pair of H4s today, now upgraded with LED bulbs which create far more lumens than the old halogens ever could, and at a fraction of the electrical load. It is true, however, that the LEDs do change the pattern slightly, most noticeable around the edges of the light pattern due to the multiple light sources in the LED bulb itself, but the effect is negligible. At the same time, I also upgraded the fogs and the white markers in the bumper to LEDs as well, all with the same degree K to give a uniform appearance. It was a bit tricky to find a bulb of the correct length for the fogs - most were too short -- but with the correct length, the beam pattern of the fogs does not change at all.
By the way, here's a great thread where Ed Scherer offered really nice bulb caps for the LED headlight conversion. I'm using them: https://rennlist.com/forums/928-foru...id-or-led.html
Within a short time thereafter I abandoned the 7 inchers and purchased a pair of 8" H4s from, of all places, my local Porsche dealer, sold for off-road use only at the time. $300 for the pair in 1987. A nice increase in light output. And a HUGE difference in looks. This is the way the car was intended to look!!
I'm still running the car with that same pair of H4s today, now upgraded with LED bulbs which create far more lumens than the old halogens ever could, and at a fraction of the electrical load. It is true, however, that the LEDs do change the pattern slightly, most noticeable around the edges of the light pattern due to the multiple light sources in the LED bulb itself, but the effect is negligible. At the same time, I also upgraded the fogs and the white markers in the bumper to LEDs as well, all with the same degree K to give a uniform appearance. It was a bit tricky to find a bulb of the correct length for the fogs - most were too short -- but with the correct length, the beam pattern of the fogs does not change at all.
By the way, here's a great thread where Ed Scherer offered really nice bulb caps for the LED headlight conversion. I'm using them: https://rennlist.com/forums/928-foru...id-or-led.html
Last edited by rjtw; Aug 18, 2025 at 07:41 PM.
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Thanks Alan. Is there a write up for which wire gets spliced to which wire? Mine is-an 85 US spec car with the 7” chrome ring DOT lights. I know the H4’s are the best, but that’s not what I’m getting. Thanks for the guidance.
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See this for 9004 (ignore 9007): The wire colors on the connectors can vary: On your car @ the H4 connector the colors are: Ground: Brown, High: R: White, L: White/Black | Low: R:Yellow L: Yellow/Black
Alan
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I remember all the threads about HIDS way back and all the wiring and ballasts?? and hassles with getting white/bright lights.
Recently as I was getting my car ready for the road again I looked at the headlights 1 night and they sucked even though I thought I had upgraded once before. Anyways I looked around amazon and ordered some bulbs, they didn't fit by a 1/4 inch, replace with true 1to1 Put them in last night --- as white and bright as you could ever want. I have not driven with them yet or have any long term experience but so simple and cheap compared to what use to be required.
for info/discussion purposes only buy at your own risk
now the parking lights
Recently as I was getting my car ready for the road again I looked at the headlights 1 night and they sucked even though I thought I had upgraded once before. Anyways I looked around amazon and ordered some bulbs, they didn't fit by a 1/4 inch, replace with true 1to1 Put them in last night --- as white and bright as you could ever want. I have not driven with them yet or have any long term experience but so simple and cheap compared to what use to be required.
for info/discussion purposes only buy at your own risk
now the parking lights