My offroad lights are running off of parking light wires (was easier) and parking light wires are on a 15A OEM fuse. 15Ax12v=180W; boo. I have two 110W (55x2) offroad light bulbs + whatever the parking light bulbs are.

I want 200W (100x2) in offroad bulbs + parking lights... (or no parking lights? Hmm.. )

So two options:

20A, leave parking lights, and have 240Watts total or so
20A, take OUT parking lights, and have 200Watts total

Is 200Watts gonna be okay on a system "rated" for 180Watts? (if I upgrade the fuse)?

 

Fuses are installed to protect the wiring downstream from them.

Over time, you'll let the magic smoke (the stuff that makes electrical devices operate) out of something....

Don't screw around with shortcuts. Install a proper rated relay and wiring to the proper power source and leave plenty of margin.

Steve

 

It's for sure solidly good advice in general, but do you think FMC put a 180W fuse on 180W wires without any margin? Even a 20W margin?

 

Fordgirl - I think the margin is in the fuse itself. Most devices pull more current at startup than they do when running. The amperage of the fuse is there to support the draw at peak load, not continuous load. Under continuous load, I suspect a 15 amp circuit is passing less than 10 amps. Anything more than this and the circuit is going to start to get "warm", which in turn increases the resistance which makes it warmer and ....

I'd be VERY reluctant to put a 20 amp draw item on a 15 amp circuit without the 15 amp circuit breaker protection.

Agree with the other guys - install heavier wiring, a higher wattage relay if needed and you're good to go. You DO not want an electrical fire on the highway.

- Jack

 

Anyone have some directions on how to wire up some fogs + a relay? Relays are a new experience to me and I know I'll be needing one to wire up my fogs...

 

I don't think I'd tempt fate here. Installing larger fuses in place of smaller ones (even by "only" 5 amps) is a good way to start an electrical fire.

 

Quintin is correct. A buddy of mine almost set his truck on fire when he kept burning out a 15 amp DRL fuse... so he stuck a 30 amp BUSS fuse in there... well, it worked for a short period of time, and then he showed me what happened to his electrical box in his truck... let's put it this way. It melted and 1/2 burnt... not to mention it almost set his truck on fire.

 

you NEED a relay. it can still be triggerd by the park lights but get its power directly from the battery. any lights you buy should come with the relay and wiring directions. the park light circuit cannot handle lights of that wattage.

 

You folks have convinced me. The lights in question on this truck are $20/pair Walmart "Baja" lights. I ordered 2x100W "Xenon White Light" light bulbs today, but whenever they come, I'll rewire this so I have a thick, fused wire coming directly from the battery, and have the parking lights turn on the relay which'll bridge that "battery" wire to my newfangled lights. That'll be my fifteen-dollar electrical fire insurance. It sounds reasonable.

 

This is the exact solution needed.

I'd suggest AWG 10 wire, a 30A fuse and a 30A relay. Plenty of safety margin.

Steve