Wiring a lightbar

[detroitdiesel4x4]

I recently picked up a whelen edge 9000 to go ontop of my 08. I was originally looking for an mx7000 but found a good deal on the edge 9000, which was my second choice (easier to see the strobes during the day) and pretty close to period correctness.

Now since i have to tap the switch box directly into the battery, is it possible to get just 12v from either battery? Or do they both put off 24v? I'm assuming the front battery puts off 12v and the rear 24v?

 

[cliffyp]

They are both 12v batteries. When connected in series you get 24v. If you are running wires straight off the battery you could technically use either. If you were to go off the rear battery you cannot ground your system to the truck you would have to make it a closed circuit back to that batteries negative post. It's probably easier and safer to just pull from the front battery, then you can just ground to the truck and not have to run all the way back and you won't have the potential of an accidental fireworks show should something go wrong along the way.

 

[MarcusOReallyus]

Only I'll make it stronger - do NOT tap into the rear battery. Bad things are waiting to pounce on you down that road.

Since electrical stuff isn't your strong point, please trust us on this.

Really, for accessories, the best place to get power is the 12v junction on the firewall. See the TM or one of the stickies for help in finding it.

REMEMBER TO FUSE IT!!!!!! Install an inline fuse close to the 12v junction.

Are you going to set it up so it only goes on when the key is on? If so, you'll need a relay. Holler and I can toss a diagram your way.

 

[detroitdiesel4x4]

Ironically i work for an electrician, LOL.

I didnt really plan on making it come on with the ignition, but it is something i'll consider if you guys strongly reccomend it. I'd rather have something well setup and reliable then something that isnt.

I will definatly fuse it for sure

So i should run the hot to the buss bars on the firewall and ground to the chassis?

 

[MarcusOReallyus]

I didnt really plan on making it come on with the ignition, but it is something i'll consider if you guys strongly reccomend it.

Either way is fine. That's just a matter of choice, really. How are you going to use it, and how worried are you about leaving it on and running down the battery? You might find it a pain to have to turn the key on every time you want to use it, or that might work best for you. It all depends on how you are going to use it.

So i should run the hot to the buss bars on the firewall and ground to the chassis?

Yep!

Do you know how much power it draws? That will will help you decide how you want to wire it up (relay or not). Are you going to have a switch on the dash somewhere?

 

[Mainsail]

Either way is fine. That's just a matter of choice, really. How are you going to use it, and how worried are you about leaving it on and running down the battery? You might find it a pain to have to turn the key on every time you want to use it, or that might work best for you. It all depends on how you are going to use it.





Yep!

Do you know how much power it draws? That will will help you decide how you want to wire it up (relay or not). Are you going to have a switch on the dash somewhere?

Isn't the bus-bar on the firewall 24 volts? I don't think 24 volts would be healthy for a 12 strobe light.

 

[K9Vic]

Isn't the bus-bar on the firewall 24 volts? I don't think 24 volts would be healthy for a 12 strobe light.

Yes it is 24v, the comment was to "Install an inline fuse close to the 12v junction.". They are NOT the same, the one you are are talking about is 24v behind the batteries, the one MarcusOReallyus is talking about is 12v next to the GP relay.

I would not connect any light bar to the 12v junction on the firewall, too many amps that can overload the fusiable link. Best to connect the switch box & power for the light bar to the 12v side battery of the battery. It is no different over the firewall 12v connection as it all comes from the same place on the battery. An Edge 9000 can use as much as 40 amps depending on the amount of strobe heads. A fully loaded model with all lights on will likely draw about 30-35 amps. So bad idea to connect it to the firewalls 12v buss.

 

[MarcusOReallyus]

I would not connect any light bar to the 12v junction on the firewall, too many amps that can overload the fusiable link. Best to connect the switch box & power for the light bar to the 12v side battery of the battery. It is no different over the firewall 12v connection as it all comes from the same place on the battery. An Edge 9000 can use as much as 40 amps depending on the amount of strobe heads. A fully loaded model with all lights on will likely draw about 30-35 amps. So bad idea to connect it to the firewalls 12v buss.

Oops! You're right! I was forgetting that junction is fed by a fusible link.

40 amps? He'll want a relay then, operated by the switch in the cab.

 

[Crash_AF]

The Edge 9000 doesn't need a relay on the 40A feed, it goes into the bar and is distributed by the relays inside. Only reason to put one in would be to have a master switch that cuts the feed.

What I did was take a 12V junction off of a junk CUCV and bolt it to the firewall, and then ran a 4GA feed wire to a fused connection at the negative of the rear battery like the main 12V feed. Then I ran my power feed for the radio, switch box and lightbar from that 12V junction. High amp car stereo inline fuses work great and are readily available for feeds like this.

 

[MarcusOReallyus]

How is that thing switched? Does it have a main feed, then a separate line for a switch?

 

[donalloy1]

Like the look of that Bar. Please send pics of finished product!

 

[Crash_AF]

The Edge series has a main power and ground cable, then a control cable with lots of small gauge wires for controlling the different functions of the bar.

 

[MarcusOReallyus]

The Edge series has a main power and ground cable, then a control cable with lots of small gauge wires for controlling the different functions of the bar.

Cool. So no external relay needed or wanted!

With that kind of current draw, I'd run ground right to the battery, if it were me.

 

[Crash_AF]

Well, that's for a fully loaded bar, with like 12 strobe heads in it. A typical draw on my bar is like 10 with four strobes and 10 halogens (4 front, 4 rear, 2 alleys). I don't think I break 20 with the whole bar lit up like a christmas tree. LOL

 

[detroitdiesel4x4]

To start off with, i got a ballast plug from work so instead of crimping or soldering the wires together, that go from the switchbox to the light bar, i soldered/shrinktubed the wires to a plug so i can just plug and unplug the whole thing to make instalation/removal easy...i was proud of myself for that idea

I used 10 gauge from the buss bar under the hood to the switch box. I wrapped everything in a wire loom and tucked it all under the dash/interior channels to make it all neat. Ran a 10 gauge ground from the bar itself and the switchbox to an equiptment ground (another thing i got from work, and proud of myself for that idea!) that i mounted on the floor right before it meets the firewall. It also holds the ground for my scanner and CB. So far its so good. I havnt had any problems with the bar, or the grounds getting hot or anything frying. I was alittle apprehensive about not grounding to the battery, but this seems to work out fine so far. I have a cell phone picture i'll see if i can upload onto here shortly. The bar looks great! I totally love the look!

 

[detroitdiesel4x4]

The lightbar only has 4 strobes, they dont seem to draw much. I ran it with the truck off (just did this to see how much power it draws) for about 20 minutes and it didnt seem to effect the battery. It also has takedowns, 2 alleys, and front and rear flashers, but they stopped working on me....the bulbs blew. I think this may have something to do with me playing with the bar before i got a proper ground on it?

 

[detroitdiesel4x4]

Here she is!

 

[MarcusOReallyus]

To start off with, i got a ballast plug from work so instead of crimping or soldering the wires together, that go from the switchbox to the light bar, i soldered/shrinktubed the wires to a plug so i can just plug and unplug the whole thing to make instalation/removal easy...i was proud of myself for that idea

I used 10 gauge from the buss bar under the hood to the switch box. I wrapped everything in a wire loom and tucked it all under the dash/interior channels to make it all neat. Ran a 10 gauge ground from the bar itself and the switchbox to an equiptment ground (another thing i got from work, and proud of myself for that idea!) that i mounted on the floor right before it meets the firewall. It also holds the ground for my scanner and CB. So far its so good. I havnt had any problems with the bar, or the grounds getting hot or anything frying. I was alittle apprehensive about not grounding to the battery, but this seems to work out fine so far. I have a cell phone picture i'll see if i can upload onto here shortly. The bar looks great! I totally love the look!

Sounds really clean!

 

[detroitdiesel4x4]

Heres a better one!