At least you got the 87 terminal right...
Headlight Relays - Again!
Dr. Detroit
Joined: Mar 2012
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From: New Braunfels Texas
Race Director
Joined: Apr 2007
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From: South Western Ontario
Dr. Detroit
Joined: Mar 2012
Posts: 10,097
Likes: 4,027
From: New Braunfels Texas
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Michael S. Palmer
Race Director
Joined: Apr 2007
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From: South Western Ontario
Fuse is based on headlight load. If you run 2 headlights then 30A is likely required. FYI, DOT regulations require protection that automatically resets on headlights in case you care about that kind of thing.
87a won't be used.
87a won't be used.
Team Owner
Joined: Jan 2006
Posts: 37,637
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From: Crossville TN
87a is not connected. The 'line' between 30 and 87a is the internal switch in the relay. As the relay turns on/off, the switch floats between 87a (off) and 87 (on).
P.S. Nice schematic, Richard....
P.S. Nice schematic, Richard....
Last edited by 7T1vette; Sep 27, 2017 at 10:21 AM.
Team Owner
Joined: Jun 2001
Posts: 23,367
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From: Virginia USA
I'm using three relays. One for regular low beams, one for high beams and one for the high beam filament in the low beam bulbs. Probably overkill but it makes my regular low beams independent of the high beam circuit. I think it's a bit safer.
My alternator puts out 14.61 volts and with my upgraded wires to the bulbs I'm getting full voltage at the bulbs. Both low and high beams are halogen bulbs. With my setup the low beams (35 watts both low and high beam filaments) on they draws 4.87 amps - 35/14.2=2.39x2=4.87. My high beams (50 watts) draw 3.42 amps - 50/14.61=3.42x2=6.84 and since each circuit is independent that is the full draw all the time. I could use 10amp circuit breakers but I chose to keep them 20amps so I have a little more fudge factor. Also installed ceramic plugs at the bulbs and with my setup I have several upgrade possibilities.
My circuit:
Last edited by theandies; Sep 27, 2017 at 06:31 PM.
Le Mans Master
Joined: May 2003
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From: Fernandina Beach FL
2023 Restomod of the Year finalist
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I actually am running a relay per light- like the Germans do separate circuits for each side.
However- I did upgrade to some Hella's with 80/100watt low/hi and 100watt high bulbs-
Relays fit neatly next to the electric headlight motors where the old vacuum actuator was-and if you look closely the black pieces between the 15A fuses are Ford diodes to isolate Hi and Low beams to run the headlight motors.
And ran some 4GU to power everything up front (headlights/electric headlight motors/horns/dual fans)
Melting Slicks
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From: Niles, MI
Thread Starter
Racer
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From: New Port Richey, FL