Why 2 headlight relays

[joetiii]

Hmmmm. I'm confused. I installed new H4's and bought the relays as everyone suggests. When I checked out the wiring for my 69 E in Haynes, I saw that there are already two relays on the car mounted to the firewall. I looked under the bonnet and there they are. What is the purpose or installing a second set of relays? Am I supposed to remove the stock relays in an effort to reduce the wire run from power source to the HL or what?

[2.7RACER]

Joe,
Yes you are right. There are two relays in the headlight circuit in your 911S.
Edit: After carefully examining the schematic I'm withdrawing my original comments.
You still need to use the new relays in the kit.
The current goes through contacts in the stalk switch and the contacts will not handle the extra current for the new lights.
The relays will carry the current and the stalk contacts will only handle the current to run the relays.

[ruf-porsche]

I think its because you have two fuses one for low and one for high beam so you have two separate circuits

[scottcip1562]

Joe, I added H4's to my 79SC and installed Daniel Sterns Relay kit. One Relay for the Low and one for the High. Ran all new wires to the lights direct from the battery. Makes a big difference. Check out his web site, lots of go info on it.

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

[imcarthur]

The issue isn’t that the existing relays can’t handle the load, it’s that the stalk – hi-beam flasher – sees all of the current & voltage & it will eventually fail. Ditto the old 18 AWG wire & bulb socket. If you increase the size of the bulb – more current – you will accelerate the process. To rewire, you put new relays between the existing relays & the lights. Then you run new power wires from the battery to the new relays & from them to the lights. Therefore the load drops on your relays & stalks – they only see the relay switching current rather than the full load - which is safely handled by the new relays & new cabling.

Ian