i know there has been alot writen on the IB forum about making your lights brighter but i can get the link to see where
you buy the relay kit or how it works  can any one help ? have you fitted a kit and ugradeded your bulbs?

Its no secret that pre 1990 911's have pretty poor headlight output.

A lot of the problem is attributed to the fact that the headlights and mainbeam have no relays for delivering the required current. Rather the current is drawn through the headlight flasher switch on the steering column. This switch has flimsy readt type switch contacts and it is common for this to burn out as a result of the high current loads. They are also very expensive to replace.

There is an aftermarket relay kit by sucro which is relatively innexpensive. I have not personally installed these so can't vouch for their quality.

I went for an OEM look upgrade. I designed a circuit diagram for the upgrade using standard porsche relays and relay holders. I worked out which fuses were required for standard and upgraded headlight bulbs. The diagram is located in the 'porsche reference library' section of the forum.

The difference is clear. After the upgrade the output was noticably brighter.

I also upgraded the bulbs to Philips H4 Xenon +80% which are all legal for MOT purposes.


Here's the diagram location:

911 headlight wiring upgrade

Here's the OEM relay and relay holder:




And here's a summary of what I did:

- installed Philips +80% xenon H4 bulbs;
- run a fused (20amp) supply to feed 2 new OEM porsche relays (i've read of some people using 30Amp. This is far too much and wont blow for the circuit. Even using 100w bulbs you should only need 28Amps);
- run the switched feed from headlight switch and main beam switch into control side of two seperate relays;
- then run the switched output from the relays back into the OEM wiring.
- For my wiring in detail see my earlier post in this thread with a detailed before and after wiring diagram.

The most tricky thing was mounting the OEM relay holders into their mounts. Just a very tight fit. Tototal wiring time was about 30 mins. I know the Sucro kit is much cheaper but using the this approach keeps whole thing looking completely OEM.

The costs:

- Philips +80% £24.99
- 2 x relays £30.00
- 2 x relay holder £56.00
- mini blade fuse holder £3.00
- fuse £0.55
Total £114.54