Wire Gauge Inquiry

So long story short, dealership replaced my "body ECU" but stated my aftermarket wiring overheated and started smoking.

I'm of the mind my old ECU wasn't putting out whatever power it should've been and this new ECU is pushing full power but my wiring wasn't the right gauge and couldn't handle it.

That being said, what gauge wire should I use for aftermarket things like light bars, rock lights, fogs? I am pretty sure 16 ga isn't sufficient and overheated...

TIA

 

Depends on the draw of the light bars. You didn't mention what size bar and how many amps it pulls. Gotta do the math

 

What does your ecu have to do with light bars, or is it two separate issues?

 

Your light bars should be wired to the battery direct with a relay - good point. Shouldn't have anything to do with the ECU.

 

It is...

 

Anything directly connected to the battery bypasses ECU involvement? So now I’m questioning why my aftermarket wiring overheated.

 

You have to give us more info. 16ga wire will run some some things just fine. Bu what do you have hooked up? What size fuse you running? Fuse should blow before wire melts. Wire gauge, length, amp draw and fuse size all play a part

 

I have fog halos, CB, 8 pc rock lights, and 42” light bar directly connected to the battery.

Everything has an in-line fuse. The bar and rock lights are remote activated. CB has full-time power and must be manually turned off as do the halos.

 

I will bet anything I need to up the gauge wire I’m using. I’m just confused as to how a new ECU would cause this if everything is direct-connected to the battery?

 

The rock lights should be fine on 16ga depending on the draw. But everything else I would think would need bigger wire. What is the draw on the 42in bar? You need to know the draw so you can make sure you have the correct size wire. How many amps does the 42 bar draw?

 

Probably needs a 20A fuse which I’m pretty sure it has. The included harness had a relay, switch, and fuse.

 

I’m running 10 gauge with a 20 amp fuse. I know it’s overkill but better safe than sorry.

 

Technician told me I should run 12 ga w/small fuse so the fuse pops quickly if a problem comes up.

 

Yeah I am not a fan of the included wire harness that companies send - just seem under sized. Upgrade to 10ga or 12ga depending on length and amp draw.

 

UPDATE: So the body ECU/fuse block fried again. The dealership tried to tell me it would be my financial responsibility to cover the repairs and I was polite when I responded "It was working when I left here, I didn't touch anything, checked the lights when I pulled into my driveway and now they aren't working. Seems to me this points to something y'all didn't check well enough." I asked to speak to the service manager. My service writer comes back with #2 in charge and says they'll cover the repair as a "one time goodwill gesture" provided that I pull off every aftermarket lighting source I have added. Seeing the compromise, I agreed to it. I was going to pull all the wiring anyway. I'm taking out the CB, light bar, fogs, and Spyders. Ugh.

The cost of the repair is $1100-1200.

 

You also need to take into account the length of the wire run as well. Plenty of charts for a good reference point on google.