jimbo74

the headlights are not using any relay power for the aux lights... the only wire off the headlights is tapped into the switch of the relay for the aux lights.....

Unhappy99

In your drawing, there is a high current path between your switch (after fuse) and the high beam wire.

Here is what happens when you turn on the high beam and have the aux switch off: The aux relay closes and high current flows from the battery to fuse to relay to aux lights....all is good.

Now flip the switch on (with or without high beams, it doesn't matter). All the lights come on, but just long enough for the fuse to blow. There is a high current path from the battery to fuse to relay to aux lights, AS WELL AS a high current path from the battery to fuse to switch to the high beams. IOW, your switch is trying to power up the high beams as well as your aux lights. You have a lower resistance path to the high beams through your wiring than the Toyota wiring, and current takes the path of least resistance.

Add the two diodes as shown, and the aux lights will come on with either high beams or your aux switch.

jimbo74

ah ok.. where would i put the diodes? i think i get what you are saying now... also i think i understand where to put the diodes... are there automotive grade diodes? or do the look like the IC board ones i am thinking of?

firemedic

I think Unhappy99 put arrows on his diagram, which is where the diodes go.

Unhappy99

go up to post #12. Expand your drawing which I modified.

The cathodes of both diodes connect to the coil side of the relay. One anode goes to the high beam wire, the other anode to the aux switch.

The 1N400x series diodes are cheap, probably $1.29 for 10 at radioshack. And yes, they are used quite frequently on IC boards. ** BUT NOT ALL diodes on IC boards are of the 1N400x type. If you are going to scavenge a scrap board, ensure you are:
A) getting a diode and not something else.
B) getting one of the correct type.

Most diodes are labelled in fine print, so look for something which has 1N400x printed on it, most common is white ink on a black body. They also have a single white band near one lead which indicates the Cathode side.

This is a Diode

jimbo74

ok that jsut chilling on a line that has that much voltage going through it? and running on 16 guage wire is ok jsut sitting htere under the hood?

i swear i saw some diodes that looked like huge fuses in my old explroer

Unhappy99

Voltage (volts) is 'on' a wire. Current (amps) is 'through' the wire. And voltage multiplied by current equals Power (watts). For example, a 55 watt lamp requires 4.58 amps at 12 volts.

The aux relay primary (coil side) needs probably 0.060 amps, which is low current in this application. 16 gauge wire is fine from high beam to diode to relay, and from fuse to switch to diode to relay. Larger diameter wire (lower gauge number, like 12 gauge or 10 gauge) is needed from battery to fuse to relay secondary to aux lights, as the lights need quite a bit of current. The only issue with wiring under the hood is that it needs to have a high temperature insulator. Common wire is rated 60 centigrade, and you really want to have wire rated to 105 centigrade to handle the underhood temperatures.

On the wire jacket is printed quite a few things, like gauge in AWG, voltage rating in V, temperature in C, and manufacturers codes and industry approvals.

The nice thing about your wiring diagram is that everything is downstream of the fuse. So, if there is a short in the wires anywhere in the switch path, relay path, etc..., the fuse blows. Keep it this way.

Those 'huge fuse looking things' on your Ex were probably just that, huge fuses rated to 120 Amps or so and about the size of a AAA battery.

jimbo74

my main power lines for the ligths are 14 guage, with the ground being 16 guage.... both are fine for my aux lights as all 3 aux lights comes up to be less than 20 amps, which 14 guage power and a 16 guage ground can handle with no problem

JoKEpLaYeR

Hey, Check out the diagram I drew for you. I think it would work without blowing any fuses.

Unhappy99

Please don't wire anything up that way.

jimbo74

i wasnt going to wire it up like that. thats very crude, probably wnough to fry my wiring harness and then i cant drive my truck....

i got some diodes out of my dead explorer...they have the whole diode diagram on them and say diode on them..... --|<--

i am jsut going to wire them up like the modification you made in post 12 and see if everything works....

JoKEpLaYeR

Can you explain why not to wire it up that way?

jimbo74

you have 2 ground points and are basically pulling 30 amp circuit through stock maybe 18 guage wire... that cant handle power like that

JoKEpLaYeR

It's just pulling enough to flip the relay. The power going to the lights is going through 30 -> 87. The wire shown coming from the headlights is not really how I would wire it - I would use the wire that grounds the lights under the dash. I forget what color it is but I found it when I was wiring up my lights.

Unhappy99

Please first explain what you believe the grey wire does which connects 85 to the two main lamps. Is this intended to be a ground?

jimbo74

i just wired it like unhappy99 said with the diodes... everything works perfectly, the way i intended it to originally work

JoKEpLaYeR

Yes, the gray wire is a negative.

Sounds like Jimabena74 has it working.

Unhappy99

Then the most obvious flaw is that since the grey wire is negative, and the red wire goes from 86 to the batt, the relay is always energized and the aux lights are always on. Even if nobody is home.

JoKEpLaYeR

My understanding was that the ground side of the headlights is the switched side.

Unhappy99

Hot side is always switched. The current path is battery to fuse to relay secondary to load. That way the wires are not hot unless they are in use. Unless you are British, then things are different.