H4/H1 Halogen Headlight Conversion

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H4/H1 Halogen Headlight Conversion

Post by bbogue » Mon Jul 09, 2018 7:14 pm

Following is a treatise (sorry it is so long) on my headlight conversion, provided for the information of anyone attempting this work.

Since my car is driven at night occasionally I wished to improve on my old sealed beam headlight system. I read here and elsewhere about the benefits of using relays to decrease power loss through the small, old, lengthy run of wires and switches. A test confirmed the voltage drop between the battery and headlights of almost 20%. ECE (European) H1 (high beam) and H4 (high-low beam) halogen lamps were selected for better lighting. I could have used halogen sealed beams but I read and heard how poor they are quality-wise from consultant Daniel Stern who has quite a good reputation in this area. He is very knowledgeable about how different types of headlights and brands of headlamps and bulbs compare. His website was helpful in setting up my system. I purchased from him a 3-relay kit with connectors, fuse holders and terminals for a 4 headlight system and 2 Koito H4 (hi-lo) lamps and 2 Tungsram bulbs...his recommendations. The relays each have 2 output terminals, one for each lamp, so splicing is minimized. Since the high beams will be used rarely and to save some expense I planned initially to keep my old bright-only sealed beams but when I received the H4 Koitos the flatter lens face made too much difference in appearance. At Stern’s suggestion to help keep the cost down, I purchased Hella H1 high beam lamps and bulbs in a kit from Amazon. The Koito H4’s and Hella H1’s look a little different side-by-side but acceptable to me. I also purchased a good crimper on Amazon and new adjustment screws and nylon inserts from Pat Wilson’s. I mounted the relays behind the battery using a convenient unused hole in the inner fender wall. The relays clip together so only one mounting hole was needed. Original car wiring included a 2-pole flat connector near the passenger side headlights. This connection was used with a 2-pole flat connector jumper wire from Tractor Supply to trigger the relays. To minimize power losses I used only 10 and 12 gauge wire (wirebarn.com) for all wiring except trigger wires. A buss bar that I installed previously near the battery was a convenient source of power. During disassembly I discovered a little rust on the headlight buckets which I cleaned up, sealed and repainted. I also had to enlarge the holes in 2 of the four buckets. 2 apparently had been replaced previously by a PO and their holes were already larger. I took my time, made several trips to the hardware store for this and that (grommets, screws, paint, etc.) but overall the project went very well. The Hella lamp connection terminals are different than on the Koitos and my sealed beams. The 2 male terminals are the smaller 1/4” variety and are at a right angle to each other vs parallel. They are also recessed. A little strange IMHO. Typical H1 connectors will not work on these lamps. Jumper wires with uninsulated flag terminals are provided to connect the lamps to existing or new headlamp connectors. I didn’t care for it...too much uninsulated exposure. So I purchased some heat shrink insulated flag terminals on eBay and wired directly from the relay. I used an iPhone lighting app as a crude way to compare light intensity before and after this upgrade. Low beam light increased over 60% and high beam light increased over 200%. Wow! I was amazed at the difference. A whiter light than the yellow light from the sealed beams, too. I’m glad I converted to a Powermaster alternator a few years ago. These lamps take some juice! Beam adjustment will come next, per Daniel Stern’s website how-to, or maybe not. I took measurements with micrometers of the existing settings and reinstalled as close as I could to those measurements, so I should be close to what I had before this upgrade. I’ll try it out a bit before I make any adjustments. We will see. In my opinion this is a very worthwhile project for a “driver” car. Good luck to those who attempt it.

VTCI# 12145
1961 Thunderbird - Heritage Burgundy Metallic
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Re: H4/H1 Halogen Headlight Conversion

Post by Rogue » Mon Oct 29, 2018 9:39 am

I did the H4/H1 conversion years ago....I used Hellas from an old Jag XJS, and they work extremely well.
Took some work, but so worth it.
Big fan of the Hella/Cibie E codes.
"Keep Cool, Little Thunderbird Ford"

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Re: H4/H1 Halogen Headlight Conversion

Post by Brushwolf » Wed Dec 05, 2018 5:57 pm

I have thought about this for several cars,but now I am seeing more LED conversions being installed. While they may be more expensive initially, they have much lower current draw leading me to wonder if the attendant relay business and high current draw issues of halogens might be avoided using those LED conversions instead.

Anyone installed LED's and have opinions on them?

Thanks, Mike

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