Umpteenth H$ upgrade question...

[Rick Lee]

Today I stumbled upon a good deal at the Potomac swap meet at Dulles In'tl Motorsport and decided to get a pair of chrome-trimmed H4's for my black '87 Carrera, which currently has H5's. I got the bulbs too and thought that was all I needed. WRONG. Where/how do I get/make an adapter for the plug that goes into the back of the bulb? The H4's have three big prongs and the plug from my H5's doesn't come close to fitting. I already have the relays and will install them too. What else do I need here? Thanks.

[Doug E]

I'd call Cy tomorrow and ask him to walk you through it since he sold you the H4's. Let me know if you need his number - I think I've got it in one of my books.

[Argo]

You can buy a universal 3 prong plug that fits the H4 "inverted U" shape at any decent auto parts store (it's quite common). The only concern I had with the plugs I bought is that the wires attached looked pretty wimpy to me - I'm not convinced that they would safely carry the electrical load long term although 3 different suppliers have assured me they would. I've already done the relay thing and replaced the stalk hi/lo switch and the dashboard headlight switch so I really don't want to introduce any weak spots in the system after all that work and $$$. I'm going to hit a salvage yard and grab a pair with heavier gauge wire.

When you wire in the new connector, accordingly to my Bentleys for your year, your wires are as follows:

Left headlight

brown = ground
blue = high beam
green/yellow = low beam

Right headlight

brown = ground
blue/white = high beam
yellow = low beam

As for which prong on the H4 bulb is which, if the prongs are oriented in the inverted "U" position, the left prong is ground, the top prong is low beam and the right prong is high beam. Here's a helpful link with pictures:Dim Low Beams

Argo
88 Targa

[Rick Lee]

Thanks Argo - that's just what I needed.

So it looks like this not the 30 min. - 1 hr. job most had described it as. Looks like I'll be doing some splicing and soldering. From looking at the backs of the H4's, it's not clear to me how they attach to my headlight buckets/fenders. Are there other parts I need too? Do I need to (horrors) drill? Thanks.

[expat]

From my recall teh top of the H4's clip over the top of a lip in the bucket at the top of the fender then you simply screw it down using a single hollow screw at the bottom.

This hollow screw holds the H4 lens in place and then another screw screws into that hollow screw to hold on the trim.

Are you screwed now I feel as if I am

Good luck, hope I've been some help rather than hinderance.

Cheers
Mark

[Argo]

The top does fit over that lip and the bottom is held on by that screw. The outer screw that fits into the inner screw is for a trim ring that fits over the H4 assembly and can be painted to match the car. The H4 assembly is a real tight fit, especially with a new gasket (which is recommended when you get the new H4's). You just have to fit the lens over the lip on top and push down firmly until the screw hole on the bottom lines up correctly with the tab inside the bucket. Be careful with that screw; it strips easily and goes in at an odd angle to correctly fit into the tab. Screw it into the tab before you put the light assembly in place so you can get an idea of the correct angle. If it absolutely won't fit correctly, you may have to bend the tab just a little bit to get the correct angle.

Argo
88 Targa