1. Welcome to PlowSite. Notice a fresh look and new features? It’s now easier to share photos and videos, find popular topics fast, and enjoy expanded user profiles. If you have any questions, click HELP at the top or bottom of any page, or send an email to help@plowsite.com. We welcome your feedback.

    Dismiss Notice

Basic Accessory wiring tips....

Discussion in 'Truck & Equipment Repair' started by Killswitch, Oct 13, 2005.

  1. Killswitch

    Killswitch Senior Member
    Messages: 246

    Hey guys.

    First let me appologize for any redundant or tedious questions, but I've searched and found little info, and perhaps this can be a searchable thread about basic 12 volt accessory wiring.

    I purchased the rubber encased floods from aw direct. They are solid lamps by the way and I can already say Id recommend them. Im sure they'll provide plenty of light.

    Now these lamps are self grounding one hot wire lamps that are 24 volts each and draw a little less than 2 amps.

    I plan on running from the power source (battery) into a fuse, through a relay, out to a simple switch and I want to just run one wire out to the lamps and split it there to run both lights.

    What size inline fuse should I use?

    What size relay?

    What gauge wire?

    On the relay.....how many posts are there and I assume one goes to power, one to ground, but would there be two posts that would go out to the lights?

    Take me to school.

    Thank you!
  2. Killswitch

    Killswitch Senior Member
    Messages: 246

    Gee....thanks for moving this to a forum no one reads.

  3. bigjeeping

    bigjeeping Senior Member
    Messages: 678

    I just wired in 4 floods and a Code3 420 lightbar on my new 450.
    everything went great and is running at full power, if you want to take a look just give me a jingle 734.368.2989

    I went a little overboard on the wire guage b/c im assuming in the future I am going to be adding additional accessories onto this circuit and I dont want to re-do the wiring at that time.

    I ran a massive 4 guage wire from the + battery terminal back with a HUGE inline fuse it must be 40-50 amps (I had this stuff laying around from a car-amp install from years ago). Once that wire goes back it branches to 2, 25amp switches with 10guage wire, one switch for all the floods, one switch for the lightbar. Then 10 guage wire away from the switches branching off to each individual flood with 16 guage wire and 12 guage to the lightbar. One 12 guage ground. Sounds complicated but pretty simple.
  4. murphyslaw

    murphyslaw Senior Member
    Messages: 443

    ok for starters, are you puting 24 volt lights in your truck? with a 12 volt circit? or is your rig 24 volt? if your rig is 12 volt this will hamper the light out put and the longevity of the bulbs. it would be like running a 6 cell maglite with 3 dead batteries.

    ok well if you have a good electrical supplier (up here i have friged north) they are a great help tell them what your doing. lamp draw how long of a wire run, and they will tell you what size wire you need. now a thing to help. to find amps when looking for a correct sized fuse. your lights are rated in watts(most likely) you take watts and devide that by volts and this will equal amps. (I.E 55watts\12volts=4.6amps. or the other way around ampsXvolts=watts) that should give you a good start. this way to can tell excactly how much of a draw you have. now with a fuse dont step up the fuse to much. if you find that your accesory is going to draw 12 amps then use a 15 amps fuse, but sont use a 25 or 30 this is asking for trouble remember you want the fuse to "pop" befor a section of your wiring. if you have a fuse that is to big you risk big damage. ok on with the info....

    on connections i would use shielded round connectors. lots of ppl use the spade style but imo the plug type are better. on all connections that are exposed to any type of liquid or lotsa dirt use a sealent on the connections(i use a product called "liquid electrical tape). this is some exceptianaly great stuff. it will also help prevent your connections from wiggling apart.

    any time you have to run a wire threw the firewall of for that matter any metal or sharp things USE GROMMETS. please please please use them they are made for a reason, i cant tell you how many time's i have heard ppl ***** about things not working because of cut and(or) shorted wires.

    dont use a solid wire. use a soft multi-braded wire. electrons travel on the out side of the wire so a 14 ga. multi strand wire will carry as much power as a 10 ga solid wire.

    dont use a wire that has a really soft insulator. but dont use a hard insulated wire these are pron to cracking and cover seperation.

    keep your wires as short as posible the longer a wire is the less power you have at the other end. here again is another thing a good electronics supplier can help you with figuring out the ressistance co-efficent(very important).

    ok sry im running on but its important that people under stand this stuff. and it dosnt help that i'm a licensed electrician. i think thats all for now but i have alota mind lapses, so ask any question you can think of i would be glad to help.
    Last edited: Oct 14, 2005
  5. flykelley

    flykelley 2000 Club Member
    Messages: 2,127

    Try www.12volts.com for answers.

    Good Luck Mike
  6. Killswitch

    Killswitch Senior Member
    Messages: 246

    Your links broken Fly. Ive seen 12volt out there on the web. Seemed like a big site and I didnt have time to investigate.

  7. flykelley

    flykelley 2000 Club Member
    Messages: 2,127

    Try this www.the12volt.com You can post questions and they have a FAQ section and tips.

    Good Luck Mike
  8. Big Dog D

    Big Dog D PlowSite.com Addict
    Messages: 1,134

    I will give you something to consider trying instead of your original plan.

    I have had numerous older trucks in the past and the biggest problems that we always had were wiring or wiring related problems that usually stemmed from things that were added, spliced, piggybacked, what ever by previous owners.

    What we started to do to prevent that on trucks that we set up now is to run a fused heavy lead (10ga. or bigger)from the battery back to a fuseable powerstrip (available through A.W.Direct) so that everything originated from one spot instead of making the battery look like a twelve tentacled sea creature. It also eliminates wires falling out of a tapped existing fuse, failing connectors etc.. It really makes for a clean neat installation for things like lights, lightbars, radios, etc......... and helps to keep the wiring intact.
  9. Killswitch

    Killswitch Senior Member
    Messages: 246

    Thats a great idea. Other than the plow and these lights I dont anticipate any other add ons, especially since Im involved in a wiring jam with the plow on this used truck I just bought. Im having to strip the entire wire harness from the plow and they are going to individually wire everything and get rid of the pin connector etc and basically wire it from scratch and make it dependable.
  10. Killswitch

    Killswitch Senior Member
    Messages: 246

    I did decide to wire in a 30 amp 4 post junction strip and will inline fuse any add ons to keep the battery clean.

    Thanks for the tip Z.

    Im in process of cleaning up a poor plow, lights, and accessory wiring job from whoever owned this truck before me. Getting it figured out and made right.

    Also adding these lights from scratch....the right way.
  11. Big Dog D

    Big Dog D PlowSite.com Addict
    Messages: 1,134

    30 Amp sounds kinda small for what your planning on doing if it's 30 amps total for the 4 posts if its rated for 4seperate 30amp loads then your all set. You don't want to just move the problem by installing something too small. Good Luck.
  12. Killswitch

    Killswitch Senior Member
    Messages: 246

    These lights only draw 2 amps each and the only other thing I may wire into it at this point would be the plow lights. Anything else would be a low amperage deal too like maybe a radio.....but Ill keep a close eye on it.

    The plow is straight to the solenoid and battery.

    Im making sure to use good proper gauge wire, fuses with not too much over, etc etc.

    I considered wiring the lamps into the reverse lights but since Im doing all commercial stuff and will be leaving them on until the particular job is finished at night Im gonna toggle switch it....
  13. PiratePlow

    PiratePlow Junior Member
    from alaska
    Messages: 19

    Wireing the head gear/plow lights

    (you'll need to use soldering skills.)

    I don’t do things quite like everyone else it seems. I've customed out my plow from the mounts up..

    With the lights, I wanted the ability to turn on/off all light functions with the flip of 1 switch (all functions tied to my trucks lighting.. parking lights, turns, low/high beams.) I also wanted to reduce cluttering electrical lines. I decided the best way to do that, was to tie all the hot lines from the head gear, to the harness in my trucks lighting systems, and tie the 1 switch to the grounds.

    I basically cut the internal ground lines in the head gear and ran the grounds together in a wire for me to put the switch on.

    Now slow down.. it looks easy and it is.. but there's a $5.00 investment and a little soldering to do. I went down to radio shack and bought 2 packs of 6amp rectifier diodes. (it was the largest rated ones they had.. and worked fine) They cost about $2.50 a pack and has 4 in each. We insert these in the power/hot sides of EACH light/filament line. Takes all of 30 minutes of simple soldering but well worth it. (I know the 6amps seem low, but considering there's 1 per filament, it's fine.)

    You see, if you just put a ground switch in.. the adjacent lights will use the filaments of other lights as their grounds.. basically, they ground themselves though adjacent light wires.(explained later).

    remember diodes only let juice travel in 1 direction, so solder them with the flow of current from the truck to the light.

    that's it! you can use a light weight switch because the ground lines don't carry the amps the power lines do. I'd also note, the cleanest place to put the diodes is in the light housings..


    ok.. the thing about lights grounding through themselves.. I'm explaining this out a little bit because it just sounded impossible for a light, having only hot wires hooked up, being able to light without a ground wire..it stumped me for a couple of hours drawing out the circuits trying to figure out what I had done wrong.

    If we look at the path in a single light bulb, we'd see that the hot wire connects to a filament, that connects to the ground side of the light, that's grounded to the truck.. so what would happen is that when the lights on the head gear received some juice from the active truck lights (turn signal for instance) the filament in the bulb next to it (the running/park light) would serve as a connection through the harness, to truck running lights, filament, to ground.. granted, there’s a lot of resistance in there and the lights are weak, but they are on.. and drawing juice.. and wearing down the lights they are drawing current through. this is why we put in the diodes.. with them in the circuit, only power can come thru the line in 1 direction.. (it's a magic thing..) and the other lights cant ground back the other way.

    ALSO: solder quick, clean and remember to use a heat sink on the diode when soldering them. (it's a little metal clip with rubber coating.. you clip it between where you are soldering, and the diode to keep most of the heat from traveling to the diode. an alligator clip will work too.

    I used disconnects at the harness to truck junction too. I used 3 pair.

    light wire diag 02 grnd based.jpg