24v power source at alternator for IBIS Light bar?

[vmaxmike]

Can anyone tell me if it's possible to pick up 24v directly off the 60 amp alternator in a M998. If so where?

Installing a light bar and would simplify my wiring harness that i need to build if I can get main power from there.

I already have a pulse tech distribution box installed I'm just trying to avoid pulling a heavy gauge wire all the way from there if I can grab 24V at the alt. Hoping to supply main power with an inline breaker for circuit protection from Alt. and then use the Pulse Tech panel for the 24v necessary for signal wires from switches to relays.

It is IBIS Tek light bar, HID and IR lights. The bar gets supplied with 24V and has relays built in that can be operated with switches.

HIDs pull 1.8A norm 4.5max bar has four of these

IR lights I still have to figure what the Amp. draw is going to be bar has two IRs

I'm guessing I need 20-25 amp total to cover everything if they ever hit Max. norm is 10-15A

If anyone has experience with these IBIS light bars I'd appreciate knowing how you wired them. specifically the gauge of wire used for main power to the bar and where you picked 24v up at.


Thanks,
M.

 

[Mogman]

Sorry I thought you meant you only needed a couple amps which is all I would pull from the alt.
It would be a good place to pick up switched 24V to power a relay (coil) but that part of the system is pretty much maxed out.
Run the heavy line to the battery box and fuse it there.

 

[Mogman]

The 60A is switched in and out by the run switch so no continuous 24V is available there.

 

[vmaxmike]

Sorry I thought you meant you only needed a couple amps which is all I would pull from the alt.
It would be a good place to pick up switched 24V to power a relay (coil) but that part of the system is pretty much maxed out.
Run the heavy line to the battery box and fuse it there.

That's the info. I needed, thanks for the quick response

M.

 

[juanprado]

You can pull up to 30amp on a pulse box lead and it will be on a circuit breaker or fuse can be used in place of breaker.

 

[vmaxmike]

I'm guessing it will take 10-12' in total length to get from my pulse box to where I'll be mounting the Light bar. Any guys sharp on their electrical engineering and can tell me what the max amps that 14 gauge wire can pull in a 24v circuit at that length?

I've Left a couple spare wires in a previous wire harness I made up , but my gut is telling me I need a heavier wire for this maybe 10 gauge ?

 

[Mogman]

Automotive Wire Amperage Capacity Chart

Recommended Length and Amperage for Automotive Wire while maintaining a 2% or less voltage drop at 12 volts Automotive Wire Size 5 Amps 10 Amps 15 Amps 20 Amps 25 Amps 30 Amps 20 Gauge Wire (AWG) 4.5 ft 2.2 ft 1.6 ft . 18 Gauge Wire (AWG) 7.3 ft 3.7 ft 2.4 ft 1.8 ft 16 Gauge Wire (AWG)...

wiringproducts.com

 

[vmaxmike]

Automotive Wire Amperage Capacity Chart

Recommended Length and Amperage for Automotive Wire while maintaining a 2% or less voltage drop at 12 volts Automotive Wire Size 5 Amps 10 Amps 15 Amps 20 Amps 25 Amps 30 Amps 20 Gauge Wire (AWG) 4.5 ft 2.2 ft 1.6 ft . 18 Gauge Wire (AWG) 7.3 ft 3.7 ft 2.4 ft 1.8 ft 16 Gauge Wire (AWG)...

wiringproducts.com

Thanks but that chart is 12v and this is a 24v circuit.

M.

 

[Mogman]

The amp rating is the same, only with 24V you deliver twice as much wattage per amp, the reference to 12V was not necessary in the article.

 

[vmaxmike]

Maybe you can clear this up for me as well, the HID shows norm. amp draw of 1.8 Max. of 4.5 amp.

Under what conditions would it pull max. and should I be engineering the system for normal, max, or max. plus a margin in respects to wire size?

There are four of these HIDs and two IR's

Judging by the wire size inside the light bar ( 22g? circled in red pic )running the IR and the fact that they are wired direct w/o a relay I'm guessing the IR's don't pull much


M.

 

[Mogman]

Maybe you can clear this up for me as well, the HID shows norm. amp draw of 1.8 Max. of 4.5 amp.

Under what conditions would it pull max. and should I be engineering the system for normal, max, or max. plus a margin in respects to wire size?

There are four of these HIDs and two IR's

Judging by the wire size inside the light bar ( 22g? circled in red pic )running the IR and the fact that they are wired direct w/o a relay I'm guessing the IR's don't pull much


M.View attachment 886749View attachment 886750

I am not sure, it could be the startup amps are higher than running amps, or based on what the input voltage is, you could see if the manufacturer has more detailed specs or contact them.
But in the end you will probably end up sizing everything for max amps.

 

[vmaxmike]

Yeah if the founders of the company weren't in prison for defrauding the government. That would be so much easier than reverse engeneering this damn thing. IBIS scammed the Gov. for milions, and got caught. Someone else bought the business and tried to make a go of it under a different name but that was short lived and they closed up shop. So getting info. isn't an option, I tried that 1st.

 

[Mogman]

You could set it up on a bench and read the actual amps at 28V, but it would probably be best to just size the wire to the max current draw.
If you are close to the max for a given wire then just go up to the next size.
Also that chart is for copper wire, there are ALLOT of folks selling copper washed (plated) aluminum wire which I would stay away from.

 

[vmaxmike]

I'd hoped someone had already been down this road and I could piggy back on their info.

Worse case I will just over size, it's likely easier than trying to hunt down the information.

I appreciate you taking the time respond.


M.

 

[98G]

Max plus a margin for the wire. Max for the breaker.

And be aware aluminum only has 61% the ampacity of copper.

 

[vmaxmike]

You could set it up on a bench and read the actual amps at 28V, but it would probably be best to just size the wire to the max current draw.
If you are close to the max for a given wire then just go up to the next size.
Also that chart is for copper wire, there are ALLOT of folks selling copper washed (plated) aluminum wire which I would stay away from.

Yeah I'm trying to keep things fairly stock appearing on this build and have been using the correct Mil. Spec Prestolite tinned copper wire.

That's my hang up actually I've run my other circuits with 14g and don't have any 10g wire that matches what's in the vehicle, I probably should just source 25' of 10g and stop truing to push a role up hill....lol

 

[vmaxmike]

Ok found a vender for Mil-spec 10ga wire , I'll make up another harness and pull power off the Pulse box.

Thoughts on ground wire, run it all the way back to battery box , or can I get away with a shorter run to one of the grounding points on chassis or engine block?


M.

 

[Mogman]

Engine block should do, one rule on the HMMWV is not to use the body for a ground

 

[Mogman]

Ok found a vender for Mil-spec 10ga wire , I'll make up another harness and pull power off the Pulse box.

Thoughts on ground wire, run it all the way back to battery box , or can I get away with a shorter run to one of the grounding points on chassis or engine block?


M.

Can you post a link to that vendor?
Thanks

 

[vmaxmike]

Can you post a link to that vendor?
Thanks

part number: m22759/34-10-0

This link is black wire

10AWG Wire - Black-M22759/34-10-0

www.milspecwiring.com

This is Red

JUDD M22759/34-10-2 #10awg Dual XL-ETFE Spec 55 Hook-Up/Lead Wire Red/25ft | eBay

25 feet JUDD WIRE M22759/34-10-2 #10awg Stranded Milspec/Spec 55 Tinned Copper Dual XL-ETFE-insulated red hook-up/lead wire. It consists of a 10awg stranded (37x26 stranding) tinned copper conductor, wrapped in a contrasting inner blue XL-ETFE (radiation cross-linked modified flexible Ethylene...

www.ebay.com