Big 3 cable upgrade crashes into ohm's law

[PlayingWithTBI]

When you did "headlight relay modification"; activation from headlight switch. Load feed power is what source again? Hot souce with key off? I missed it.

The wire going to the headlights will activate the relay(s) which will send battery power to the headlights.

Here's a schematic I drew up using 3 relays...

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[thegawd]

I'm kinda confused, they operate as normal. Most of the headlight wiring is still there, it is used as the trigger wire that operates the relay that powers the headlights directly from the battery. this mod can be done many ways but I chose to re wire the headlights with new wire that was the same gauge as the original. I roll my own but I have bought a couple kits that I then rewired with solder and double wall shrink wrap just to get all the components. this is unnecessary but it makes for a nice clean job.

Al

 

[PlayingWithTBI]

The idea is to have all 4 headlights on when you hit the "high beam" switch and to get full battery voltage to them so they're a lot brighter than trying to force almost 10Amps through an 18ga wire just for the low beams and higher through a 16ga wire for the high beams plus, you're running both sets at the same time.

 

[thegawd]

I didnt mean that towards you Peter. I understand that perfectly. A necessary Mod in my opinion, I also have my low beams running off the battery as well. my wiring is similar but I only used 2 relays.

 

[PlayingWithTBI]

I understand that perfectly. A necessary Mod in my opinion, I also have my low beams running off the battery as well. my wiring is similar but I only used 2 relays.

Sorry for the misunderstanding. I'm planning on using 3 (with each on its own fuse/breaker) so I don't get any back feed and I hate using diodes. I've thought about 2 relays and am still open to doing that if I can see a diagram how it's done. I may be overthinking it too. I tend to do that sometimes

 

[Schurkey]

I hate using diodes. I've thought about 2 relays and am still open to doing that if I can see a diagram how it's done.

Never heard of using three relays. I used two, with a diode.

I made it a point to pull power from the firewall-mounted power distribution studs mounted on the right side of the firewall--'88 K1500. This prevented throwing more voltage at the headlights than they're rated for, so I retain full service life from the bulbs.

http://www.automotiveforums.com/vbulletin/showpost.php?p=7207868&postcount=1

 

[PlayingWithTBI]

Never heard of using three relays. I used two, with a diode.

As I mentioned, I hate using diodes. I've seen times where they will bleed and cause all kinds of issues trying to troubleshoot circuits. This was in an industrial environment where downtime costs were $1000s/Hr so we discontinued using them unless necessary in bridge rectifiers etc. The reason for the 3rd relay is 2 fold.

1) I will have 3 fuses or circuit breakers protecting the circuits so, if I hit high beams and there's a short going to low, I still have power to high and vice a versa.

2) Each circuit in turn will always be protected separately.

You're right in using circuit breakers but, I would only use one in the low beam circuit. All the others, I would use fuses since, if I have a short I don't want it to keep resetting and add more heat which may cause other issues like arcing and fire maybe? I would also go 150% of rated load to eliminate ghost issues from in-rush etc. The wires need to be rated at least as high as the fuses. Just my opinion as well as NEC.

We all have our own way of doing things and I don't want to piss anyone off - I'm just going by my life's experience in industrial automation and controls

 

[Frank Enstein]

mine comes off the alternator charge post to 2 auto reset circuit breakers then to the relays.

 

[Mr Eric]

Federal code requires headlights operable without key on, acc or engine running. Sooo... When you did "headlight relay modification"; activation from headlight switch. Load feed power is what source again? Hot souce with key off? I missed it.

Federal law may require then for a new car manufacturer, but who's looking over the shoulder of some guy working on that's 20-55 years old?

Lots of different ways to wire this chair.......

 

[Ehall8702]

As I mentioned, I hate using diodes. I've seen times where they will bleed and cause all kinds of issues trying to troubleshoot circuits. This was in an industrial environment where downtime costs were $1000s/Hr so we discontinued using them unless necessary in bridge rectifiers etc. The reason for the 3rd relay is 2 fold.

1) I will have 3 fuses or circuit breakers protecting the circuits so, if I hit high beams and there's a short going to low, I still have power to high and vice a versa.

2) Each circuit in turn will always be protected separately.

You're right in using circuit breakers but, I would only use one in the low beam circuit. All the others, I would use fuses since, if I have a short I don't want it to keep resetting and add more heat which may cause other issues like arcing and fire maybe? I would also go 150% of rated load to eliminate ghost issues from in-rush etc. The wires need to be rated at least as high as the fuses. Just my opinion as well as NEC.

We all have our own way of doing things and I don't want to piss anyone off - I'm just going by my life's experience in industrial automation and controls

What are your thoughts on this way? I'm mecp certified and been installing mobile electronics over 25 years now, I see no issues this way, power to relay is fused from keyed source so if relay sticks it won't leave lights on when key is off. Pull relay or relay malfunctions, oem operation is defaulted to.

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Forgot to say this is LED only , halogen bulbs pull way too much for this on factory wiring.