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How much power can be safely drawn on the headlight circuit?


sp838

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Sorry Docc, are you saying you have removed your headlight from the headlight relay?

I think Guzzi allowed for the Voltage drop to boost the Voltage to 14+

Without the headlight Voltage drop you can boost it up by creating an artificial drop in the black wire.

 

 

Sent from my shoe phone!

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Sorry Docc, are you saying you have removed your headlight from the headlight relay?

I think Guzzi allowed for the Voltage drop to boost the Voltage to 14+

Without the headlight Voltage drop you can boost it up by creating an artificial drop in the black wire.

 

 

Sent from my shoe phone!

Yes, I removed my headlamps (and horns) from the factory relay circuits  (and from the switches).

 

Somehow, my R/R throws 14.2 v.

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That's interesting, I thought it would drop the battery down a bit

Would you mind measuring the Voltage drop from battery + to the regulators black wire, just unplug it enough to get the meter probe on it.

 

With no load on the headlight relay I think charging should be more reliable.

 

 

WARNING, I'm going to wander off topic a bit

My EV (very similar wiring) stopped charging altogether on a trip, would barely crank. I didn't have time to troubleshoot it so I took a hot wire from the battery and wrapped it around the pin for the regulator's black wire so I knew it was getting a good reference.

A bump start got me going and I tried cranking next time I came to a hill, the charging was obviously working again. In hindsight I think I must have had a faulty Headlight relay.

 

You can actually get a VII home without a regulator (I had to do this when I first got mine), a large diode or bridge rectifier will charge the battery but you have to keep the revs down or it overcharges and the ECU cuts out. On that note if the regulator were to quit it still has at least one good diode, ground one yellow wire from the alternator, connect the other to both yellows at the regulator and it should produce half wave DC out the red wire, no need for the reference connection.

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I installed two relays one for low beam and one for high beam. I just used the stock wiring and relays to trigger the relays. Battery still charges at 14.7 volts. My head light is so much more brighter even the high beam dash light is very bright.

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I installed two relays one for low beam and one for high beam. I just used the stock wiring and relays to trigger the relays. Battery still charges at 14.7 volts. My head light is so much more brighter even the high beam dash light is very bright.

Then obviously I am wrong about the Voltage drop adding to the regulator Voltage. I did some testing on the bench and found the regulator stopped firing the regulator rectifiers at 13.8 Volts and assumed thats what it would charge too.

 

Yes I estimated my headlight was about 20% brighter.

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  • 1 year later...

I found that the regulator senses the Voltage on the headlight circuit downstream of the relay and it likes to see 13.8 Volts between the black reference wire and the case

 

I still haven't found this reference wire. Which one is it coming into the regulator?

 

When you say downstream of the headlight relay, where exactly can you check it? At the headlight?

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