Adding Relays

Voeltagear

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Hey everyone, I'm getting the pen and paper out to draw up a new charging and accessory wiring diagram. I have a 6 circuit fuse and relay box, plenty of 14ga and 12ga wire as well as some 8ga. I need some 4ga for the alternator to the circuit breaker. I'm planning to use relays for the voltage regulator, ignition system, headlights, 2 speed electric cooling fan, and an auxiliary 12v outlet. Do you have any other suggestions? Pictures of your component mounting, wiring? All feedback is welcome! Thank you in advance.
 

Duke5A

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Electric fan is the only thing that needs relays and the headlights could benefit from them. It's a common trick that circumvents the voltage loss of having to draw the current through the headlight switch - they'll brighten up a bit. As for everything else I'm scratching scratching my head, why? Don't mess with the voltage regulator and ignition. Those circuits are fine as is. Your aux 12v outlet only needs a suitable fuse for the max draw of the outlet. Don't go relay crazy.
 

Voeltagear

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Come to think of it, there is a relay already for the voltage regulator. The field and load relay.
 

Mikes5thAve

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I thought it was just whatever is associated with alternator and voltage regulator. In any case I'd follow what's stock for that and not re invent anything.
 

Aspen500

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Headlight relays work great. You can eliminate voltage drop through the dash switch and dimmer switch. Plus it takes the amp load off them also.

I went from (engine running) 11.4 volts low beam and 11.0 high beam to 12.8v at idle, hi and low beam after adding a pair of relays. At night the difference in light output is like, well, night and day. That's with Hella H4 (?) conversion headlights.
Relays in a modified Audi TT battery fuse panel. Upper right corner in the photo.

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Voeltagear

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Headlight relays work great. You can eliminate voltage drop through the dash switch and dimmer switch. Plus it takes the amp load off them also.

I went from (engine running) 11.4 volts low beam and 11.0 high beam to 12.8v at idle, hi and low beam after adding a pair of relays. At night the difference in light output is like, well, night and day. That's with Hella H4 (?) conversion headlights.
Relays in a modified Audi TT battery fuse panel. Upper right corner in the photo.

View attachment 50338

View attachment 50339
That looks awesome! Also, that's the exact problem I'm trying to remedy. I'm dropping into the 11v range with headlights on.
 

Aspen500

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It's also nice having brighter headlights because the older you get, the more light you need to see. Trust me :(
 

Lightning II

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Headlight relays work great. You can eliminate voltage drop through the dash switch and dimmer switch. Plus it takes the amp load off them also.

I went from (engine running) 11.4 volts low beam and 11.0 high beam to 12.8v at idle, hi and low beam after adding a pair of relays. At night the difference in light output is like, well, night and day. That's with Hella H4 (?) conversion headlights.
Relays in a modified Audi TT battery fuse panel. Upper right corner in the photo.

View attachment 50338

View attachment 50339

I just now recognized the that fuse & relay panel. VAG used them on the Golfs and Beetles too.
 
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