Headlight wiring question

[Stan Gillis]

I have a 73.5 911T in which I will changing the healights to H4, adding relays, ceramic bulb connectors and 16 gauge wiring. My question is how do I re-wire through the plug in connectors on each side of fender/luggage area?

[Stan Gillis]

Test

[hessel1974]

The wires which go into the connectors are molded in there. I don't see how you can replace these wires to thicker wires without destroying them.

Why would you need to go to thicker wiring? Are you planning on a high wattage H4 set up? Otherwise just use the existing wiring for you H4's. We all have that in Europe.

[Stan Gillis]

Thank you for answering. The bulb that I will be using are Hella 100/55 W. I was told by the supplier of the bulb sockets and relays to use 12 gauge wiring.

[HarryD]

Stan:

When I did mine, I drilled a small holes through the fender and the headlamp bucket for the new wires. The holes were sized for a rubber gormmet that the wires would totally fill to provide a weather tight seal (each with a dab of RTV). I left the stock wiring and connectors in place.

[Steve@Rennsport]

Hi Stan,

Love that Jade Green,.....

12 gauge wiring is recommended and relays are needed for such a bulb upgrade as well as protection for the dimmer switch.

Harry offered an excellent suggestion to get the wires into the headlight bucket.

[Stan Gillis]

Hi Harry, Great idea on how to re-wire and not disturb the original wiring. Where did you drill that hole in the fender?

[Stan Gillis]

Hi Steve. Yes, I too agree on the wiring gauge size. Thank you for your advise. The color of my car is called Viper green. Been restoring this car for about 23 years. The body shop took 16 months to complete. My next electical issue will be the right headlight.

[HarryD]

It was up front of the battery box.

[Stan Gillis]

Sounds like the logical spot. I assume that I can also use the original hole in the headlight bucket as well. I thank you and Steve for helping you have given me.

[Steve@Rennsport]

Originally Posted by Stan Gillis

Hi Steve. Yes, I too agree on the wiring gauge size. Thank you for your advise. The color of my car is called Viper green. Been restoring this car for about 23 years. The body shop took 16 months to complete. My next electical issue will be the right headlight.

My pleasure, anytime.

LOL, I need to adjust my monitor's color rendering,......

[Stan Gillis]

Thanks to all for your technical help in assiting me on this headlight updating requirement.

[Stan Gillis]

My right headlight does not switch to high beam. I replaced with new turnsignal/headlight switch, headlight relay, and replaced all fuses and cleaned fuse box. Have very little knowledge of checking electrical. However, I do have a meter and test light. Hopefully someone can tell me what to do. The body shop did replace both front fenders with FG.

[wildcat077]

Stan,

I just installed the relay kit last weekend in my 89 and i only had high beam on the right hand side,turns out you have to install both the yellow and white wires on the top terminals of the fuse block... I had one installed on the bottom and one on top.You also need a good ground going to your H4 socket inside your headlight buckets !

If you like i can take some pictures tonight of inside the headlight bucket for the wiring and the fuse block for correct installation.

Cheers!
Phil

[HarryD]

If you wired you lights the way i did mine, you will see that I used the power from Fuse #1 to energize the High Beam Relay and the power form Fuse #3 to energize the low beam head relay. Each relay uses it's contacts to take power from the battery to the headlamps. Is this how yours is wired?

[docrodg]

Sounds like a wire issue on the highbeams. Phil probably hit it right on in his suggestion. I also recommend that you ensure good ground by not only scraping paint off where the connection is but also (to prevent rust) coat with some dielectric grease. A thin coat will do the trick and prevent the connection going bad. I know someone who used silicon caulking on his work truck for this and it did not turn out very well, but the grease has worked for me for many years.

[Stan Gillis]

Both headlight socket grounds are connected directly to the battery ground clamps. So I'm thinking something else.

[wildcat077]

Stan,

Here you go,as promised and since i'm getting really good at removing and taking apart my headlights i went in the garage and took a few pics for you... lol

Hopefully the wiring pics will be of assistance to you,if there's anything you might want to know about the installation feel free to ask

Cheers !
Phil

[Stan Gillis]

Phil, Thank you for the pictures, however, on my 73.5 911T the fuse block is quite different. I have two boxes. The top box has 10 fuse connections and the lower has 8 fuses. The lower box #1&2 are the right and left high beams and the #3&4 are the right and left low beams. I have not installed the relays as yet, until I resolve the right high beam issue.

[wildcat077]

Stan,

Regardless of how your fuse boxes are situated i believe that you might have to run your high and low beam wires in series to your relays...
You might try running your high and low input wires spliced together into the relay,one series for the left lights and another for the right and do the same for the output wires.Your input wires from the relay would go on the top of the fuse block and the output would go to the wires you removed from the bottom of the fuse blocks.

Since you would be running the power through the relays anyways i don't think it would danmage anything if this solution didn't work out !

The only other idea would be to run two sets of relays,one for the highs and another for the low beams ...
Just an idea !

Cheers!
Phil