Custom wiring

[one4fun]

86 K10 with quad head lights and H4 bulbs in all 4. As it is now, low beam turns on top low beam filaments only. High beam is both filaments on top and bottom. I want to connect an isolated toggle switch that i can turn on the low beam filaments on the bottom lights regardless of whether the headlight switch is on or not.

My question: If i had a separate switch connected as suggested above, had the low beams turned on to the lower lights and then turned on my high beams using the headlight switch, it's going to send power to both filaments on the lower lights. Is this going to fry something or cause an "electrical conflict"?

My lighting is upgraded with relays, ceramic bulb sockets and heavy gauge wire. The addition of a separate switch would also include relays, etc.

Thanks.

 

[chengny]

So currently:

You have dual filament lamps in both the upper and lower H/L assemblies

When on LB's - only the low wattage filament in the uppers is hot. The other three are dead.

When the dimmer is switched to HB's - all 4 (i.e. both filaments in both lamps) are hot.

You want to add an additional power supply to just the low wattage filaments in the lower assemblies. One that can be operated independently of the OEM headlight circuitry by the use of a dash mounted switch.

So, I guessing here, you want to be able to:

1. Have the low wattage filaments in both uppers and lowers on at the same time - by having the factory system on low beams (to illuminate the uppers) and your manual switch closed (to illuminate the lowers).

2. Also have the option to operate just the low wattage filament in the lowers - while everything else is off.


And finally, your concern is regarding this scenario:

You have the low wattage filaments in the lower assemblies energized (via the added/ independently switched power supply). Then you use the normal circuitry to turn on the headlights - and they are in the HB mode.

The lower wattage filaments in the lower assemblies will then have two hot power supplies connected to them. One from the independent source and one from the normal wiring. You wonder if this will cause any problems.


The short answer is; no.

Even though there are two 12 volt supplies to the filaments they don't add together or anything like that.

The load will be divided between the two incoming leads. How much will be supplied by each wire will depend on several factors (wire size, distance from the power supply, tightness of the connections, etc). Also it the percentage of the load carried by each will fluctuate during operation.

The entire H/L circuit is common (as is the truck's entire electrical system). Think of the hot side of the electrical system as a big shared pool of energy with all the components drawing from it only what they need to work.

But, I know what you are thinking. Like, can an outside power source go backwards up the wrong wire or force feed too much power to a component, etc.

No worries, you will be alright with what you want to do.

 

[one4fun]

Perfect. Thanks!