Wiring for protective headlight relays - Alfa Romeo Bulletin Board & Forums

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post #1 of 2 (permalink) Old 03-14-2017, 03:17 PM Thread Starter
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Carlos Vasconce's Avatar
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Location: Porto / Portugal
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Wiring for protective headlight relays

I could really do with some advice from experienced hands here...

In my Giulietta Sprint '59 I want to use some stronger bulbs (not sure which yet but the normal ones are not very helpful at night...) and to that effect I am "inserting" 2 relays (one for main beams and one for low beams) right after the fuse box. I have managed to get some 075mm2 gauged wire in the appropriately textile braided colour code which I intend to use between the fuse box and the relays.
Up to fuse box wiring is 1x2.5mm2 and after relays wiring is 2x1mm2 gauge.
Question 1: Is it ok to use this 075mm2 between the fuse box and the relays (2x0.75mm2)?
Question 2: the relays need live current supply from somewhere...where should I get it from?
(Note: my guiding info is Papajam's Wiring Diagram for Giluietta Sprint 10102-R6)

Thank you in advance for any helpful advice

Carlos Vasconce is offline  
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post #2 of 2 (permalink) Old 03-14-2017, 04:00 PM
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Location: Örebro, Sweden
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0.75 mm2 is good enough between the fusebox and the relays, they don't draw much current. You could take the current from the dynamo or the starter, depending on where you want to place the relays. I would use at least 2 mm2 wire and keep the combined length, source -> relay -> head lights, as short as possible. Both are good for minimizing the voltage drop. Don't forget to put a fuse in this circuit, 10A should be good for two 55W bulbs.
Sune Karlsson is offline  

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