Q: H4 Upgrade on a 1987 911

[spsfiend]

I purchased new H4 headlamps and would like to perform this upgrade from the current H5s I have on my 1987 911. Do I need to purchase any hardware to perform the upgrade or are the H4s a direct replacement? I read that it is recommended I install a higher capacity relay. Is there any other wiring harness adapters that I need to purchase or does the current wiring harness work?

Also, does our host sell the hardware that holds the lamp in place? I notice when I removed the H5s that I am missing the screw on the right of the lamp on both sides.

Thanks so much!

[Canada Kev]

Do the relays. It's easy and will save your turn signal switch.

The plugs for your H5 bulbs won't fit an H4 bulb. You will have to replace. There are many places which will sell you the plugs with pig tails to wire up to your existing wiring, or maybe just the plugs themselves that you can terminate on the wires. Do a google search or contact some of your local auto parts places.

The light assembly itself will just bolt in. Its easy. Other than the bulb plug issue, its a two minute affair for each side. I believe you can even reuse your H5 trim ring.

Oh, I should qualify this... I am assuming that you are installing euro H4s? If so, everything I said applies.

[flatsixjunky]

I did it and syzygy is right, new pigtails and that's all if you're using 55W bulbs, if you intend to use the 100W bulbs then a relay is needed, this is the one I got (JWest relay kit ) easy does it. If I did it you can do it.

[65_lincoln]

I am pretty sure that you cannot use your H5 trim rings with H4 headlights. That is one reason that I haven't changed mine over (the other is that I don't drive much at night). I guess I'm too lazy to put in the effort to get a set of H4 rings painted to match body color.

[flatsixjunky]

I notice when I removed the H5s that I am missing the screw on the right of the lamp on both sides.

from spsfiend

You don't need them with the H-4's, they use only one screw on the bottom of the ring, nothing else, sounds weird I know but the ring clips on top and sides to the headlight bucket in the fender and the bottom screw keeps it tight.

take care

[KTL]

For a simple change to H4, you don't need anything but the correct female wire plug to connect the car wiring to the H4 bulb. But the headlight relays are not required only because you're switching lights. The relays are needed because of a poorly designed electrical circuit on the 911 that puts an excessive amount of current through the turn signal stalk. By installing the relay kit, you are taking/relaying the the current load of the headlights from the switch and putting it into the relays- hence the reason it's called a relay!

Like the others said, if you choose to install higher wattage bulbs, not only do you want to install relays but it's also recommended you upgrade the wiring. The existing wiring in the car is a very small gauge and can overheat. Heavier gauge wiring is a good idea to avoid a wiring meltdown. I'm sort of an electrical nimrod and even I figured out how to rewire my headlights

Euro H4 Install- Replacing H5 Lights

I like the H4 but I will say that how it mounts is crap. The H5 is much better with it's solidly mounted aiming cage that is screwed to the tabs inside the fender's headlight bucket. The single screw at the bottom of the H4 is crap because it's very easy to strip the threads in the bottom mounting tab. Plus the extra trim ring is a pain in the butt. The Porsche H5 could have been a really good light if they had used the H4 lens and bulb with the H5 mountings

[flatsixjunky]

The single screw at the bottom of the H4 is crap because it's very easy to strip the threads in the bottom mounting tab.

from KTL

True, ask me how I know.

[KTL]

One of mine is on the the verge of fully stripped. When it goes i'm going to either:

1. Re-cut threads to M6 x 1.0 size

or

2. Put in a self tapping screw like my friend did on his '86

[911S Targa]

Do the relays. It's easy and will save your turn signal switch.

I did the relay's on my euro h4 upgrade, but removed the old wiring that led to the back of the headlight's, which come to find out, also house the turn signal wiring. So needless to say, I dont have any turn sig, or running lights anymore. What do I do to correct this ?

[KTL]

Originally Posted by 911S Targa

I did the relay's on my euro h4 upgrade, but removed the old wiring that led to the back of the headlight's, which come to find out, also house the turn signal wiring. So needless to say, I dont have any turn sig, or running lights anymore. What do I do to correct this ?

On my '87 the headlight wiring is completely separate from the turn signal wiring. In the picture below, the gray wire on the far left of the picture contains the turn signal wires. The group of wires in the middle are the new wires I ran to supply power to new, higher wattage bulbs. The group of wires on the right are the original wires that I disconnected at the main fuse panel, but left in place and put some heat shrink on them to "block off" the ends and prevent any unwanted short circuits.

So your headlight wiring and relays you installed really should have nothing to do with the turn signal lights- it's a completely different run of wires!

[vtrich]

In making the switch, before you actually install the new lamps, install the retaining screw at the bottom of the headlamp bucket. Doing this before hand, you will be able to note the angle of the screw, and then, lessen the possiblility of getting it started at the wrong angle and subsequently stripping it when you actually install the lights.

When I did my conversion, I wired in the "city" lights. These are very low wattage bulbs,..I think 4 watts,... and can easily be spliced into the side marker lights.

A quick search will give you all the info you need about these and the wiring.

Finally, I was frustrated trying to locate the compatible female plug needed to connect the H4 bulbs. Maybe it's cause I live in the sticks,..but any pigtail I found used really thin wire.

GOOD luck,..I think it's a great upgrade.

Rich

[KTL]

Very good advice from Rich. I'll second his mention of the poor quality H4 plugs. I got my H4 female plugs from Daniel Stern Lighting.

http://www.danielsternlighting.com/products/products.html

Their site doesn't list the part number, but he sells a very nice high heat female plug end that has spring-loaded wire connection terminals. Pretty trick little plug end. I think it's made by Hella, so quality is good.

[flatsixjunky]

Thanks KTL and vtrich,

So this means that my connection and the pigtails I bought from pep boyz is cr%p?

Why didn't anybody told me this during my thread (http://forums.pelicanparts.com/showthread.php?t=462602) when I asked how should I go about doing this the right way?

Where can I get a decent stalk to replace the cr&p the car comes with?

KTL can you post the part number from Daniel Stern Lighting so I can order the real thing?

Thanks

[flatsixjunky]

So this is a nightmare waiting to happen?



Thanks

[KTL]

I'm sure you'll be fine. You got a LOT of good feedback from some very helpful people in your original topic, so don't sweat it.

The Stern site doesn't list a part number so you have to call them or email them.

[flatsixjunky]

Thanks KTL,

I just read through your posts here: (http://forums.pelicanparts.com/showthread.php?threadid=144248).

Very helpful and detailed I'll guess I'm doing this again, the best way this time.

Thanks

O-

[JeremyD]

I'll 2nd the daniel stern plugs - and I'll also 2nd the crap H$ mounting system. The lens quality is heads and tails better than the H5 lens

[m110]

I had a female H4 connector melt after a blast through the desert with high wattage bulbs...I bought a ceramic plug for my current car. Probably overkill, just one option available.

[RM3Racing]

The prior owner of my 1987 cut the H5 connector out on the passenger side of the car. I'm installing new LED headlights that use an H4 connector and want to replace the connector on both sides of the car. Any suggestions on the best way to approach this? I was going to purchase the H5 to H4 adapter from the sponsor and splice that into the car after cutting off the H5 side, but is there a better option? What gauge of wire is the stock wiring for the headlights that I will be splicing into? Lastly, I am going to add hood mounted lights (think rally style light pod), so should I dive into a more intensive wiring update here? If so, what would the recommendation be? A headlight and fog light rewire? Any resources to help me figure out what's needed here to rewire these?

[RSBob]

Originally Posted by KTL

One of mine is on the the verge of fully stripped. When it goes i'm going to either:

1. Re-cut threads to M6 x 1.0 size

or

2. Put in a self tapping screw like my friend did on his '86

Had this issue and inserted a small sheet rock plastic anchor in the stripped reciever and it holds like a champ. Cost was free. After a year, recut the threads because I as in there.

Tip: To prevent an improperly seated H4 assembly, because seating can be an issue, from taking an unscheduled departure from your headlight bucket onto the tarmac, secure the back of the lamp to the wiring assembly with a zip tie.