Switch Power- Source?

Dutch123 · #1 (**permalink**) 06-08-2009, 06:31 PM

Installing driving lights- have a lead (according to directions)for "switch power" What/where is the source for this?

Thanks-

Franklin2 · #2 (**permalink**) 06-08-2009, 07:54 PM

What is the total wattage of the lights, and how do you want them to work, i.e. do you want them to come on with the headlights, or have a separate switch for them? Do you want them to work with or without the ignition being on?

Dutch123 · #3 (**permalink**) 06-08-2009, 08:38 PM

Ok- 100w total; would like these to work independent from the headlights- but with ignition on. (Separate switch I have)

Dutch

Franklin2 · #4 (**permalink**) 06-09-2009, 10:48 AM

100w at 12v = 8.3 amps. The best way to do this is mount a bosch type foglamp relay under the hood near the battery. Hook a inline fuse rated around 15 amps to the battery +, and then run this to the relay contact. Come out of the other relay contact and run to the lights. Use at least a 14 gauge wire for these connections.

For the coil of the relay, hook one side of the coil to a metal ground near the relay. Connect another wire to the remaining coil terminal, and run this all the way inside cab to your switch. Come out of the other side of the switch with another wire, and run this to the fuse box. Go buy some little gizmos they call "fuse taps". This will let you hook the wire from the switch into the fuse box. Pick something that is only on with the ignition on, such as the radio or possibly the blower motor. That will let the lights only work with the key in run, though if you hook it to the radio fuse, they might also work in acc position too.

Dutch123 · #5 (**permalink**) 06-09-2009, 02:29 PM

"fuse taps"- that's something I need to know... I diagrammed out your explanation and it is doable. So, am I supposed to add the 8.3 amp draw to whatever I fuse tap it to- and make sure I do not go over a certain fuse rating. Say a 15amp fuse for the radio- but what does the radio draw 11amps- so add these 8.3 and 11 (estimated) which is 19.3 so I need at least 20amps- Is my thinking on the right path here.

getting ready for shuttle lauch 6-15-09

Dutch

f250ssd · #6 (**permalink**) 06-09-2009, 03:04 PM

Here is a diagram with relay hookups that I drew for somebody else.
You could hook up the switched power to something that only comes on when you turn the ignition. With a relay hookup you don't have to worry so much about the current draw of what you hook up the switched power to, because the relay coil only uses about 150 milliamps.
The picture I drew is for an eight light system, but one of the relays there, is for two lights.

Dutch123 · #7 (**permalink**) 06-09-2009, 08:56 PM

Ok- I've got what I need

happylogan1 · #8 (**permalink**) 06-29-2009, 06:27 PM

BTW- Ran into a snag; obviuosly need to run wire assembly from engine bay into the cab. I have a 3/8" male-female connector (rectangular) that needs to find it's way. Should I drill this diameter hole- or bore out to this diameter an existing hole which currently is passing wires into the cab?

Cranks

Franklin2 · #9 (**permalink**) 06-29-2009, 08:16 PM

It's already made up on the underhood end? I guess you have already checked if you could undo this end and route the wire through the firewall from the inside, if the connector is going to end up being on the inside.

Otherwise, I guess a 3/8 hole is going to be required. They are a little bit expensive, but you can go to the store and buy what they call a "uni-bit". It's a stepped looking drill bit that makes a beautiful hole in sheetmetal.