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Headlight rewire

EFI Wiring Fundamentals

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Discussion and questions related to the course Motorsport Wiring Fundamentals

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hello everyone I own a 1976 Chrysler galant and I have a Vr4 galant 4g63t in it Ive just started to look at rewiring a few things. First of all i want to use tefzel wire. Im starting with the headlights which Im reusing. They are twin sealed beam. The original loom doesnt have any relays so Im wondering what gauge wire i should use in tefzel? Ignition to starter wire gauge? And the Altenator wire gauge? Pretty shore they are 90amp from factory.

Your headlights are probably 50 - 90watts per bulb (about 4.2 - 7.5 amps @ 12 V). You should be able to use 18 ga wire (probably would be OK with 20ga) to each lamp, If you are splicing grounds, you may need to use something larger (14 ga for two lights).

I like to use a fairly heavy gauge for starter solenoid (12-14 ga) as this circuit can draw some power especially when the starter is hot.

Alternator output -- I suggest you use 6 ga for a 90-100 amp alternator.

Thanks for your help David

Hi David

Whats the best way to hook up Vr4 starter motor and alternator? Im not using the old wiring harness. My battery will be relocated to the boot. Main power from the starter will go straight to the battery with a fuse. What size fuse would I need to run? Now the 12-14 gauge solenoid wire you recommended. Where does it hook up to? With the alternator there are 3 terminals to wiring up? B terminal with a nut on it which Im shore goes to battery. Does this mean I have to run another cable to the battery including the main from the starter? Then you have the S terminal and the L terminal. Heres a photo of the alternator. Where do they wire up to?

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Well, you'll need to learn about alternators, lamp circuits, field currents, etc to determine the wiring for the alternator. I would start with the factory wiring diagram and try to understand how they have it connected and duplicate that.

Similar for the Starter -- starters normally ground to the engine block, and have a heavy current wire that is triggered by a solenoid (often attached to the starter). With the battery located far away from the starter, you will need a very large gauge wire to avoid voltage drops due the the resistance when cranking current is passing through it. Perhaps 2 or 0 gauge. Make sure the ground path is just as good (heavy gauge wire from battery to chassis, and from chassis to engine).

Thanks David

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