Will this wiring modification work

[hunter]

I'm adding another factory FXSTDI headlamp to my Deuce.  I'm thinking that if I splice a couple relays into the factory hi/lo supply lines to the original headlamp, I can use the ignition sourced power supply to control the additional headlamp while still providing power to the original headlamp.  In fact, my first true lesson in electricity came when I held a phone ringer with uninsulated wires and plugged it into the household current.  The wires vaporized and the ringer fell to the floor.  So....

Will this work?

[FSG]

No.  It's my zzzzzZZZZZZZ time, I'll redraw it for you tomorrow if someone doesn't do it in the meantime.

[Dakota]

   I really don't see how it wouldn't work if all you're doing is using the existing headlight wiring to control the relays, unless a relay draws enough power to overload the headlight wires.  I'm also assuming that you're providing the power for the extra headlight via separate wiring and not from the original headlight wires.  I don't know how many amps a relay draws, though.

[Dresser]

If the relay diagram in FB's reply is correct your wiring isn't going to work.

[96dynabagger]

That wiring is definately wrong in that it connects to the wrong relay
terminals.  For a good description of the relay wiring, see:

http://www.the12volt.com/relays/relays.asp

[Admiral Akbar]

I'm adding another factory FXSTDI headlamp to my Deuce.  I'm thinking that if I splice a couple relays into the factory hi/lo supply lines to the original headlamp, I can use the ignition sourced power supply to control the additional headlamp while still providing power to the original headlamp.  In fact, my first true lesson in electricity came when I held a phone ringer with uninsulated wires and plugged it into the household current.  The wires vaporized and the ringer fell to the floor.  So....

Will this work?

My first experience with electricity was to stick a butter knife into a light socket. Dad kept having to replace the fuses in the fuse box. Not sure he ever figured out why until I got caught trying to suck the water out of the toilet bowl with a vacuum cleaner.. Didn't wave wet vacs back then.

Nope wont work.

Need to ground 86

Use 85 for control to the switch. 87 for one beam and 87A foe the other..

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I wouldn't use this circuit. I'd use only one relay to power the extra headlight and control the relay of the low beam. That way if you loose either fuse, you only loose one headlight..

Max

[hunter]

See, this is why I almost electrocuted myself.  Please understand, I'm not trying to argue but understand and this kind of thing hurts my head.

I recognize this type of relay is commonly used to allow low current switches in the cab to control high power devices under the hood.  I've used one to manually control the glowplugs on my diesel truck for extended ops with my 9G plugs.

Why wouldn't the 85-86 trigger still flow current based on the amp draw?  And wouldn't it still provide sufficient current to power the 60 watt bulb and then seek a ground through the existing one in the headlight while controlling the 30-87 triggered contact?

Regardless of how stupid my drawing is - which probably should result in a warning for this thread - I'd appreciate a drawing that demonstrates how I can tap into the existing hi/lo power supply to the existing headlight to control an additional headlight that's powered separately to avoid overloading the existing circuit.

SECOND EDIT:  I think I get it.  I'm going to try to draw an individual circuit and repost.

[Admiral Akbar]

"And wouldn't it still provide sufficient current to power the 60 watt bulb and then seek a ground through the existing one in the headlight while controlling the 30-87 triggered contact?"

Nope.. You drop all the voltage across the relay and almost none across the bulb. BTW not call the drawing stupid.. Trying is half the battle.. Max

[hunter]

How about this instead?

And FSG, what am I doing wrong with my picture posting?

[attachment removed after 60 days by system]

[Admiral Akbar]

Should work but you could use 87A for the low beam.. Max

[hunter]

But if the 30 poll is always hot, wouldn't that mean that one of the lights - either the hi via the 87 or the lo via the 87A - would always be on?

[Admiral Akbar]

Thats correct. Isn't that what you want? Max

[hunter]

No.  I'm trying to use the hi/lo switch and its associated wiring to control the original headlight and trigger power for the additional headlight to receive power directly from the battery.  With the key off, I want neither headlamp powered.  With the key on, I want both headlamps to be on hi or both headlamps to be on low depending on the hi/lo switch position.

BTW, I very much appreciate your rapid responses.  Once I get things in my head, I can't let it go...which explains the existance of the Deuce, my boat, my spouse....

[Admiral Akbar]

Gotcha,,

I assumed the source was switched. In your case you've got it.. duplicate for the low beam and you're done.. I suspect know that..

Max

[hunter]

I had hoped!  Thanks again.  I'm off to plan the continued devolution of the FrankenDeuce.

[crazycalvin]

I just looked at the factory service manual for my Deuce and it doesn't show any relays for the headlight.  It looks like they run up to 15 amps through the switch.  I would have thought they would have triggered a relay with the hi/lo switch and ran the main headlamp power through the relay, thus giving a low current control circuit and high current circuit isolation.  I will have to look closer at my manual and make sure I didn't miss anything.  Later, Calvin.

[hunter]

Nope, you've got it correct.  My Service Manual diagram shows the same thing - a direct load line coming off the keyed switch protect by a 15Amp fuse running through the hi/lo switch.  I'll be adding the relays.  I'm hoping to get them in the headlamp buckets themselves...both in the additional headlamp if they'll fit.

To that end, where can one acquire high quality wire, connectors and relays?  The wire I can acquire in the small town in which I live is the chinese junk that's brittle and likely not pure.  How about small relays?

[Scramjet]

Those relays are available at the auto store for about $12 but they are not small.  About the size of a 1"x1" cube, maybe a bit smaller.

B

[crazycalvin]

First of all the thinnest wire I would use for your project would be 14 AWG, but would probably consider 12 AWG due to the extra ampacity.  Second, I would make sure all of my connections are good and would even double up the crimp connectors with solder and heat shrink.  Third, you can get the wire, connectors, and heat shrink from Lowes or an electrical supply house.  Last but not least, you might be able to get one relay and wiring into a headlamp assembly, but I think two will be tight.  The two problems I see with tight are: wire chaffing and heat dissipation.  Hope this helps and let us know how it turns out.  Later, Calvin.

[hunter]

Got it.  Yeah, I couldn't find anything under an inch on the internet.  I figure I can put one in each of the buckets.