More headlight questions

ianc · 02-15-2005, 07:51 PM

Hello all,

I asked for a little FAQ on headlight options the other day and was told to do a search. So, I did. And found 7,348 threads about headlight upgrades. So I spent about two hours weeding through them and learned some. But I still have questions. So please don't tell me to search again.

It looks like there were\are three types of headlights available: H1's (wasn't really able to figure out what they are), H4's (the bright ones the Europeans use), and H5's (which the Carreras used and which apparently suck). So, it would look like the H4's are the way to go. Here are the questons:

1) I heard mention of DOT H4's and non-DOT H4's. What is the difference, and how does one tell by looking at them? Why are the non-DOT H4's worse?

2) It seems like the standard H4 assembly comes with a trim ring in either black (primer) or chrome. You can either paint the black, or purchase an additional trim ring to fit over the top of this to paint. Is this correct? Which of these options most closely matches the look of the stock Carrera (84-89)? How does the extra trim ring attach? Is it expensive? Primed also?

3) Every H4 installation must have additional relays installed to handle the increased juice instead of sending it through the already overloaded dimmer stalk. Some people advocate using two, some four. I liked the idea of using the two empty relay slots in my existing relay\fuse panel for this. Is this feasible and has anyone ever done it? Are different relays (with two terminal 30's) available to fit these sockets?

4) My overview of the wiring process is that you essentially attach a couple of large wires to the battery, one for highs and one for lows. These run to terminal 87 of the relays. Terminal(s) 30 of the relays head to the lights themselves, and a separate ground from the lights is added. Finally, the control current for the relay is run through the existing high and low beam wires from the dimmer stalk. Am I battin' 1000?

Thanks for any help,

ianc

RoninLB · 02-16-2005, 05:09 AM

Quote:

Originally posted by ianc

1) I heard mention of DOT H4's and non-DOT H4's. What is the difference, and how does one tell by looking at them? Why are the non-DOT H4's worse?

3) Every H4 installation must have additional relays installed to handle the increased juice instead of sending it through the already overloaded dimmer stalk. Some people advocate using two, some four. I liked the idea of using the two empty relay slots in my existing relay\fuse panel for this. Is this feasible and has anyone ever done it? Are different relays (with two terminal 30's) available to fit these sockets?

4) My overview of the wiring process is that you essentially attach a couple of large wires to the battery, one for highs and one for lows. These run to terminal 87 of the relays. Terminal(s) 30 of the relays head to the lights themselves, and a separate ground from the lights is added. Finally, the control current for the relay is run through the existing high and low beam wires from the dimmer stalk. Am I battin' 1000?

1] Euro H-4 and DOT h-4 have different optics. The lens of DOT will have glass tits on the lens for the alignment tool. It will either be etched DOT or "E". Most shops will supply only DOT for legal reasons in the US. "E" is not technically legal in the US.

3] 4 relays & fuses is technically safer. If you blow one low beam fuse you still have another. I bought 2 stock relays for the elec panel, but decided to use 2 75amp relays instead. Stock 30amp relays are fine.

4] a single 10ga hot and ground from the battery T'd to the 2relays are fine. Solder all connectors, use dielectric, and I suggest marine fuse housings and AWG wires. Proper fuse size is generally sized to allow 70% current draw. So a 10amp fuse is sized to 7amp draw.

I figure your using greater than stock watt bulbs? If so get the high heat/heavy duty bulb connectors.

fwiw, it would be easier if Bosch H-4 wording was used when relating to the 911 Bosch lens.

Early_S_Man · 02-16-2005, 06:26 AM

There are six headlamp assemblies used in production from 1963 thru 1989 ...

1. Hella 'Euro' model using Type 'A' replaceable incandescent bulb.

2. Hella USA using USA sealed beam bulbs.

Both of the above are quite similar to VW Beetle/Bus headlamp assemblies with clear oval lenses from 1949 - 1966.

3. USA 'sugar scoop' Hella assemblies using DOT sealed beam bulbs, and without lenses over the bulbs.

4. 1969 Bosch H1 headlamp assemblies for 'Euro'/ROW markets with twin reflectors and four adjustment screws to aim high and low beams separately.

5. 1973-86 Bosch H4 headlamp assemblies with two external adjustment screws on the trim ring.

6. 1987 - 89 H5 assembly.

Both #2 and #3 can be fitted with replacement conversion units that take the place of sealed beams and use H4 bulbs. Those 'conversion bulbs can be eithe USA-spec DOT with aiming 'tits' or E-code for ROW markets ... not to be confused with unit #5!

steve911 · steve911's Garage

Quote:

Originally posted by ianc
It looks like there were\are three types of headlights available: H1's (wasn't really able to figure out what they are), H4's (the bright ones the Europeans use), and H5's (which the Carreras used and which apparently suck). So, it would look like the H4's are the way to go.

H5's actually came on 87+ Carreras. US-spec 84-85 Carreras and 78-83 SCs all came with regular sealed beam headlights.

Here are the questons:

What RoninLB said, plus this:

There are Hella H4s that are direct drop-ins for the original sealed beam bulbs. They retain the stock US look.

Then there are the Bosch H4s that require a completely new headlamp assembly and new trim rings. They provide the European look headlamps.

2) It seems like the standard H4 assembly comes with a trim ring in either black (primer) or chrome. You can either paint the black, or purchase an additional trim ring to fit over the top of this to paint. Is this correct? Which of these options most closely matches the look of the stock Carrera (84-89)? How does the extra trim ring attach? Is it expensive? Primed also?

Stock US Carreras came with sealed beams; ROW came with European H4s. If you are looking to retain the stock US-look, then the Hella H4 drop-ins will be your ticket.

ianc

Bill Verburg · Bill Verburg's Garage

While there are several varients the major cosmetic differences come down to the type of trim rings used.

The 2 cars is the foreground have US DOT 7" sealed beam bulbs, there are variants w/ H4 or incandescent bulbs, there are also some that use euro non-sealed H4, one is paited and one is chrome, both are often called "sugar scoops"

The car in the background has the euro style thin trim

Here are 2 euro C3s both have euro H4s, mine in the foreground has painted, while the othe has chrome rings, both are thin and fairly symmetric.

another shot of euro style, this one is a '74 euro Carrera

ianc · 02-17-2005, 09:12 PM

Hi Guys,

thanks very much for all your responses! Since I wasn't able to get an answer to question #2 however, I just went ahead and bought a set of H4's today with the chrome trim rings (primed not available) and am hoping that either the chrome can be painted over, or that the outer trim rings I asked about can be had. Got them very cheap since my roommate owns a shop.

I am going to use the two empty slots in my fuse\relay panel with the standard relay (911 615 109 01) and a couple of circuit breakers to protect them. I'm figuring on 20A. Does that sound about right?

Thanks again for the help. After reading all the threads I did, I was really hoping RoninLB and Early_S_Man would check in. Bill Verburg is alway welcome of course. Not to slight you, steve911 (because every little bit helps), but I have read mucho from these other guys and they really seem to be on the 911 lighting ball. Take care,

ianc

RoninLB · 02-17-2005, 09:57 PM

Quote:

Originally posted by ianc

Since I wasn't able to get an answer to question #2 however,

I am going to use the two empty slots in my fuse\relay panel with the standard relay (911 615 109 01) and a couple of circuit breakers to protect them. I'm figuring on 20A. Does that sound about right?

I was really hoping RoninLB and Early_S_Man would check in.

I don't know much about the Bosch H-4.

Read our info above again.. Also there are 2 circuit breaker designs. It may be an issue if you live in a hot climate and you're using the technically correct CB size.

fwiw, Bill always has nice installs.. any everyone has something to offer, no matter what it is.

ianc · 02-18-2005, 01:14 AM

Hi RoninLB,

I scratched at this tonite and came up with a diagram. I expect it's the same everyone else has used, but it helped me think. The parts that concern me are the red circles. Your message above say it's OK to 'T' the wire. I see three places where I need to do this:

What is the best technique to make a 'T' like this? It seems like it would be difficult to make a strong connection with a 'T'...

I plan on soldering all connections, and I usually use heat shrink tube to seal this, but haven't used dielectric before. What is it: grease? Coat the soldered joint before shrinking tube on it?

Thanks again,

ianc

70SATMan · 02-18-2005, 07:23 AM

An easy way to accomplish the tee is using an unused terminal block connection. Main line in and dual lines out. Makes troubleshooting easier. Also if you were to use a factory fuse block you can individually fuse the lights for added safety and redundancy.

RoninLB · 02-18-2005, 01:52 PM

use 10ga branching into two 12ga.

what I meant by a "T" is a soldered branch. Can do whatever is acceptable to your install.

Maybe you want to try brighter bulbs with high temp sockets? 130/100w is doable because our car's headlights are low and 100w low won't blind others on a flat road if aimed correctly. Warren mentioned Hella bulbs awhile ago that have stronger highs. A few pelicanheads have tried the 100w low and love them with E-code lens'. More powerful highs come with bonus coupons that push left lane slowbees away.

Dielectric is a high temp corrosion protector for connectors. It's very clean of impurities and is wonderful with anything electric, especially any elec noise sensitive units such as computers/ignitions/etc. A tube of Loctite silicone dielectric is around $20. I don't know about other good dielectrics? For your lighting circuit axle grease is better than nothing. Those bulb socket connectors take a beating. Connector "dirt" leads to voltage loss.

this is a great project.. you're gonna love the results.

fwiw, I like using silver solder that I get from Radio Shack. I don't know where else to buy it?

ianc · 02-18-2005, 04:06 PM

Hi RoninLB,

OK, I'll grab some dielectric and slather it on the soldered joint prior to shrink tubing it. I'm not sure if my solder is silver or not, but I did buy it at the Shack...

70SATMan,

Thanks for the suggestion, I hadn't thought of that! Back to the wiring diagram...

ianc

randywebb · 02-18-2005, 07:04 PM

No reason to use a dielectric grease if you are soldering a connection - it is useful for wires that are screwed together, or similarly connected.

HarryD · 02-18-2005, 10:34 PM

Daniel Stern has much to say on this topic. Check him out here: